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Minimum F-Stop for portrait work

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Anonymous
August 6, 2005 8:55:26 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Hi all,

I'm getting close to purchasing my first Canon L series lens for portrait
work - every review I've read suggests that the 85mm F1.2 L is a real
honey - but I've also read better reviews of the 135mm F2.0 L series.

Today I've had a bit of a play with an online DOF calculator and if what I'm
reading is correct then I suspect that I'm never going to be able to use it
wider than 2.0 because the DOF range is so small we're getting to a point
where if the eyes are in focus then the tip of the nose will be out, and the
ears waaay out. I'm curious as to what you good folks feel is the minimum
F-Stop (ie largest aperture) for portrait work?

Also, am I correct in assuming that if I presently position my camera approx
1m away from my subject with a 50mm lens then I'll have to be at 2.7m with a
135mm?

Thanks,

CC
Anonymous
August 6, 2005 8:55:27 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <42f460cf$1@dnews.tpgi.com.au>, Pixby
<pixby_douglas@hotmail.com> writes
>
>There is such a thing described in almost every book on the subject of
>portraits as "the perspective of a portrait". Some techno geek from the
>frozen wastes of Canada told me perspective is not tied to focal
>length. For a portrait it is. He is yet to show me his "traditional
>portrait" taken with a 14mm lens. (Douglas sniggers quietly)

Well, the "geek" was (mostly) right and you were (mostly) wrong.
Distance perspective* is determined purely by distance. If you take a
picture from a set distance with a wide and a tele, and crop and enlarge
the wide shot to cover the same area, the two will be identical
(ignoring pixellation and any other resolution effects).

* I use this term to avoid confusing the issue with those arising from
poor drawing in the corners of extreme wide angles, or perspective
distortion arising from tilting the camera. If you fill the frame of a
14mm shot with a face, the geometric effects in the corners will indeed
distort the extremes of the face (which is why I said "mostly" above).
Of course, you probably would not be able to get a clear image anyway as
the subject's breath would be fogging the lens from about 3" away....
>
>For the purpose of discussing the artist merits of images taken with a
>camera, I will offer you the suggestion that you get a better
>perspective to your portraits when you use a telephoto lens. You will
>need to move farther away than with a normal lens.

And there you have said it yourself. Using a 135mm lens does not of
itself affect perspective, but to get the same field of view you have to
move further away, which does affect perspective
>
>The 85mm Canon Portrait lens is a really nice lens but if you have 1.6
>crop factor, you'll get too much depth of field and it will be too much
>length, for studio portraits. Why not try the (relatively) inexpensive
>50mm f1.8?
>
Nice lens, but surely one which will (other things being equal) give
greater DoF not less.

David
--
David Littlewood
Anonymous
August 6, 2005 8:55:27 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <42f4966c$1@dnews.tpgi.com.au>, Pixby
<pixby_douglas@hotmail.com> writes
>
>Just keep in mind that whatever DOF you would have at the lenses FL
>(say 50mm), the same lens on a digital will 'look' like it's a 75 mm
>but have the DOF of the 50 mm lens. The 1.6 crop factor is cropping the
>image, not magnifying it.

Not quite. Agreed a 50mm lens is always 50mm lens, and it is a mistake
to use "35mm equivalent focal length" figures in DoF formula. However,
the DoF figures assume a constant enlargement factor in producing the
final image; in order to fill the frame with a given figure crop, a 1.6
digital will need to be enlarged additionally by this factor to get to
the same size as an image from 35mm. Thus a 50mm lens will have a DoF of
approximately 2.25 that of a 75mm lens (1/f^2) before this factor (i.e.
if both are being used on the same format) but only 1.4 times (2.25/1.6)
on a same-size final image where the 50mm is being used on a smaller
digital sensor.
>
>f5.6 is the (Canon) digital equal to f8 in full frame and is what
>eminent flash makers like Metz, recommend for a starting point in
>portraiture. To use apertures wider than f5.6, you really need to know
>what you are going to get. The purpose of a fast lens is not so much to
>take impossibly shallow shots but to be able to see and focus with them.

Though they are highly useful in poor illumination; I use a Canon 35mm
f/1.4L as my preferred lens in museums, for instance.

David
--
David Littlewood
Related resources
Anonymous
August 6, 2005 8:55:27 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <sD_Ie.711$iM2.56328@news.xtra.co.nz>, Cockpit Colin
<spam@nospam.com> writes
>
>> I use a 50mm 1.4 lens for most portraits. This is roughly equal to the
>> 75mm of a true portrait lens however...
>
>My kit lens maxes out at 50mm - but at this distance I've got the camera
>only about 1m from my subject - so I'm assuming that with a 85mm lens I'd be
>a touch under 2m, which should be fine - is this a valid assumption???
>
>The issue I'm having is getting the shutter speed high enough to freeze a
>moving subject while I fire off a burst of shots. Many may not like this
>approach - and no doubt I'll improve my technique - but what I'm after is
>portraits where the subject (ie daughter for now) isn't just smiling, but is
>"squealing with delight" - only way I've found to get the ones I want is to
>take a burst whilst I make her laugh - but at F5.6 (even under strong
>lights) my shutter speeds are waaaaay too slow @ 100 ISO (I used to like the
>grain of higher ISOs, but soon discovered it's too much if the photo is
>being blown up). I'm gambling that a faster lens will make all the
>difference (even if I also have to use ISO 200 at a pinch). What I'm hoping
>to capture is something that'll be sharp when blown up to perhaps 150 to
>200% and framed on a feature wall)
>
Then your lighting is inadequate. In bright sunlight you should get
1/500 to 1/800 for f/5.6 at ISO 100 (depending on what latitude you are
at). If you are inside, try using flash.

David
--
David Littlewood
Anonymous
August 6, 2005 8:55:27 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Cockpit Colin wrote:

> Hi all,
>
> I'm getting close to purchasing my first Canon L series lens for portrait
> work - every review I've read suggests that the 85mm F1.2 L is a real
> honey - but I've also read better reviews of the 135mm F2.0 L series.
>
> Today I've had a bit of a play with an online DOF calculator and if what I'm
> reading is correct then I suspect that I'm never going to be able to use it
> wider than 2.0 because the DOF range is so small we're getting to a point
> where if the eyes are in focus then the tip of the nose will be out, and the
> ears waaay out. I'm curious as to what you good folks feel is the minimum
> F-Stop (ie largest aperture) for portrait work?

There are portraits and there are portraits. Most people who have their
portrait done for "family" or "corporate" style want themselves to be in
focus from the nose to the ears. For full figure (or head to thighs),
more DOF usually looks better. an f/2.8 or better lens in 50mm to 100mm
(for cropped sensors) is ample, but such a lens will begin to peak on
sharpness at about f/5.6 to f/8.

Photographers and art department editors may have need for photos where
there is feature isolation (eye in tack sharp focus, other eye soft,
nose soft, etc...). So a fatter (f/1.4) lens is best.

The f/1.2 and f/1.0 lenses are more bragging right than anything else,
and are not noted as particularly sharp compared to the f/1.4 lenses in
the portrait range.


>
> Also, am I correct in assuming that if I presently position my camera approx
> 1m away from my subject with a 50mm lens then I'll have to be at 2.7m with a
> 135mm?

Yes, FL is proportional to distance for the same framing.

(note that a lens that says "50mm" might be 48 or 49; and a lens that
says 135 might actually be 131 or so).

Cheers,
Alan



--
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-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: Remove FreeLunch.
Anonymous
August 6, 2005 9:03:16 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Cockpit Colin wrote:
> Hi all,
>
> I'm getting close to purchasing my first Canon L series lens for portrait
> work - every review I've read suggests that the 85mm F1.2 L is a real
> honey - but I've also read better reviews of the 135mm F2.0 L series.
>
> Today I've had a bit of a play with an online DOF calculator and if what I'm
> reading is correct then I suspect that I'm never going to be able to use it
> wider than 2.0 because the DOF range is so small we're getting to a point
> where if the eyes are in focus then the tip of the nose will be out, and the
> ears waaay out. I'm curious as to what you good folks feel is the minimum
> F-Stop (ie largest aperture) for portrait work?
>
> Also, am I correct in assuming that if I presently position my camera approx
> 1m away from my subject with a 50mm lens then I'll have to be at 2.7m with a
> 135mm?
>
> Thanks,
>
> CC
>
>
Depth of field for a digital camera is a hell of a lot greater than with
film SLR. That having been said, the focal length previously considered
in 35 mm circles to be a "portrait lens" is too long for digital with a
1.6 crop factor. This is 75mm to 90mm, depending on the maker.

I use a 50mm 1.4 lens for most portraits. This is roughly equal to the
75mm of a true portrait lens however... The lens is too sharp for mature
aged portraits. I partly overcome this with the use of a "Duto" filter.
These are hard to come by now but are clear glass with circles etched on
the glass. They soften an image - ironing out wrinkles and other skin
imperfections. You can get a similar effect by lightly sandblasting a
filter. I have also used the body oil from scraping where your nose
joins your face and smearing it on a filter. This provides a soft look.

I wouldn't bother too much about the eyes/ears focus depth. Many of my
best portraits concentrate on the so called 'features' of a person's
face. It is only in reportage and travel shots, sharpness is beneficial
to a portrait. Some of the most highly regarded portraits from well know
photographers are softly focused. The digital brigade would probably
call them out of focus due to their lack of detail.

There is such a thing described in almost every book on the subject of
portraits as "the perspective of a portrait". Some techno geek from the
frozen wastes of Canada told me perspective is not tied to focal length.
For a portrait it is. He is yet to show me his "traditional portrait"
taken with a 14mm lens. (Douglas sniggers quietly)

For the purpose of discussing the artist merits of images taken with a
camera, I will offer you the suggestion that you get a better
perspective to your portraits when you use a telephoto lens. You will
need to move farther away than with a normal lens.

The 85mm Canon Portrait lens is a really nice lens but if you have 1.6
crop factor, you'll get too much depth of field and it will be too much
length, for studio portraits. Why not try the (relatively) inexpensive
50mm f1.8?

--
Douglas,
You never really make it on the 'net
until you get your own personal Troll.
Mine's called Chrlz. Don't feed him, he bites!
Anonymous
August 6, 2005 9:03:17 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

> The 85mm Canon Portrait lens is a really nice lens but if you have 1.6
> crop factor, you'll get too much depth of field

You will? I used it on a DR XT for some portraits, and at f/1.2, I
couldn't keep both eyes in focus unless the subject was facing 100% directly
at the camera. I just looked at one of the shots at f/1.6, where the
subject is rotated just about 10 degrees off of facing the camera. One eye
is tack-sharp, the other is just a tad soft - only noticeable if you look
for it - and the tip of the nose and ears are noticeably soft. When facing
about 50 or 60 degrees from the camera, one eye was very noticeably soft,
and that was at f/1.6 as well.

In fact, any wider than f/1.6 is just likely to ruin the shot unless you
*are* specifically trying to accentuate only one part of the face. If I
wanted to focus on the eye and not have to worry about keeping the entire
face in focus, I would stop to 2.0 or 2.4. Even at 2.4, in a shot with
three subjects lined side-by-side, but not *quite* perpendicularly to the
camera, one would be just a tiny bit soft. Not enough that you notice it on
a 5x7, but still a tiny bit soft.

The 85mm f/1.2 is a fine, fine lens. The only potential downfall for
portraiture is that the images are razor-sharp, especially once you're
stopped down to f/1.6 or smaller. If you want soft-focus, you'll have to
either use a filter, do it in post, or buy a soft-focus lens. Well, that
and the fact that you do need some room in order to fit much in the frame on
a 1.6 body. I shot a group portrait of 11 or 12 people with it, and it just
happened to work out perfectly - the location they wanted the portrait in
was right against a small duck-pond in the reception center. I walked
around the pond, and was at a very good distance for the shot. : )

steve
Anonymous
August 6, 2005 9:23:18 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

> the focal length previously considered
>in 35 mm circles to be a "portrait lens" is too long for digital with a
>1.6 crop factor. This is 75mm to 90mm, depending on the maker.

Agreed. Many folk refer to 135mm as portrait length also, but lets not
quibble.

>I have also used the body oil from scraping where your nose
>joins your face and smearing it on a filter.

Gross. Buy a soft filter (and keep any oils and greases away from your
camera equipment - this sort of practice should have died with
magnesium flash..). They are easy to find. Check secondhand camera
stores. You can also do post-processing (look for soft-focus actions
on the net, plenty to play with - and before anyone asks, no, they are
*not* the same as blurring!), but the real filters are best. Actually,
a real Softar lens is best, but let's not go there...

>Some of the most highly regarded portraits from well know
>photographers are softly focused.

What, like your famous, but now-withdrawn (as usual) 'tells a story in
a face' portrait? No, wait, that didn't get any 'high regard' from
anyone..

>The digital brigade would probably call them out of focus
>due to their lack of detail.

The 'digital brigade'? If that is meant as an insult, I would observe
that there are just as many talentless people in either camp - right,
Douglas? Digital folk tend to know how to process their images
properly for web display, though. I guess that's where we differ.

>Some techno geek from the frozen wastes of Canada told me
>perspective is not tied to focal length.

It isn't. The techno geek was right and still is, as were ALL the
other folk on that thread who tried to get it through to you. If you
hold all other things equal (and if you don't, the question is
meaningless) - perspective is strictly a function of distance from
subject. Proof - take an image on a zoom at, say, 28mm. Now, *without
moving*, take a second image at 80mm. Examine the *same area* of both
images, and you will notice that the perspective is the same. The
field of view changed, that's all.

OF COURSE you will have to move closer to the subject if you want the
same image from a 28mm lens as that from an 80mm. And by MOVING, you
changed the perspective. Evereyone else seems to be able to grasp this
concept...

>For a portrait it is. He is yet to show me his "traditional portrait"
>taken with a 14mm lens.

If *anyone else* has a problem with this concept, I will happily post
an image taken at 14mm that shows this concept, along with several
other images that prove beyond any reasonable doubt that it is DISTANCE
FROM SUBJECT that changes perspective.. But no-one else seems to have
the problem, Douglas, and I'm certainly not bothering for you.

>(Douglas sniggers quietly)

Douglas childishly embarrasses himself again - rather like his
signature, which is indicative of his maturity..

>For the purpose of discussing the artist merits of images taken
>with a camera, I will offer you the suggestion that you get a better
>perspective to your portraits when you use a telephoto lens.
>You will need to move farther away than with a normal lens.

Bravo - by adding that last line, you hint that even *you* understand
that perspective changes with distance, not focal length. I guess it
is at least in your subconcious.

>The 85mm .. is a really nice lens but if you have 1.6 crop factor,
>you'll get too much depth of field

The only additional d-o-f he will get is from the additional distance
he is from the subject, and it is a f1.2 lens for heaven's sake...

>and it will be too much length, for studio portraits.

Depends on his shooting style and studio layout. I often use 135mm,
even 200mm (35-equivalent) zoom lengths. Having a 135mm-ish f1.2 would
be rather nice..
Anonymous
August 6, 2005 9:39:31 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <spMRElHMdM9CFw9s@dlittlewood.co.uk>,
david@nospam.demon.co.uk says...
> Though they are highly useful in poor illumination; I use a Canon 35mm
> f/1.4L as my preferred lens in museums, for instance.

I am envious. If you die, please make sure you have willed that lens to
me.
--
http://www.pbase.com/bcbaird
Anonymous
August 6, 2005 10:55:13 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <MPG.1d5ebfe12dfbf1499897ae@news.verizon.net>, Brian Baird
<no@no.thank.u> writes
>In article <spMRElHMdM9CFw9s@dlittlewood.co.uk>,
>david@nospam.demon.co.uk says...
>> Though they are highly useful in poor illumination; I use a Canon 35mm
>> f/1.4L as my preferred lens in museums, for instance.
>
>I am envious. If you die, please make sure you have willed that lens to
>me.

They're not ^that^ expensive (and besides, my daughter has her eye on
it).

David
--
David Littlewood
Anonymous
August 7, 2005 12:35:41 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

> I use a 50mm 1.4 lens for most portraits. This is roughly equal to the
> 75mm of a true portrait lens however...

My kit lens maxes out at 50mm - but at this distance I've got the camera
only about 1m from my subject - so I'm assuming that with a 85mm lens I'd be
a touch under 2m, which should be fine - is this a valid assumption???

The issue I'm having is getting the shutter speed high enough to freeze a
moving subject while I fire off a burst of shots. Many may not like this
approach - and no doubt I'll improve my technique - but what I'm after is
portraits where the subject (ie daughter for now) isn't just smiling, but is
"squealing with delight" - only way I've found to get the ones I want is to
take a burst whilst I make her laugh - but at F5.6 (even under strong
lights) my shutter speeds are waaaaay too slow @ 100 ISO (I used to like the
grain of higher ISOs, but soon discovered it's too much if the photo is
being blown up). I'm gambling that a faster lens will make all the
difference (even if I also have to use ISO 200 at a pinch). What I'm hoping
to capture is something that'll be sharp when blown up to perhaps 150 to
200% and framed on a feature wall)

I was getting excited about the 135mm F2.0 L lens - one of the reviews
described it as "the perfect portrait lens" - but I didn't check what sort
of camera he was using it with - probably safe to bet is wasn't with a 1.6
crop factor camera :( 

I'm leaning towards the 85mm F1.2 L - I really don't know what I'll think of
the DOF - but I think it'll give me the most options (can always stop down
for better DOF) - and for portraits it sounds like it's a safer bet @ 85mm.
I'll probably get the other one as well - it sounds like it would be a good
choice for trips around the zoo.
Anonymous
August 7, 2005 12:35:42 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

> so I'm assuming that with a 85mm lens I'd be a touch under 2m, which
> should be fine - is this a valid assumption???

2 meters, or maybe a touch over it would probably work for a face-only
picture. If you want a full-body picture, you have to move back, back,
back, back.

> I'm leaning towards the 85mm F1.2 L - I really don't know what I'll think
> of the DOF - but I think it'll give me the most options (can always stop
> down for better DOF) - and for portraits it sounds like it's a safer bet @
> 85mm. I'll probably get the other one as well - it sounds like it would be
> a good choice for trips around the zoo.

Don't forget that it's big, fat, heavy, and slooooow to focus. : ) It's
also expensive - the 50mm f/1.4 that someone (Pixby?) mentioned will also
take fine portraits, at about 1/5th the price! Call around and see if
anyone local to you will rent you the 85 and/or the 50, and play around with
them for a day, then decide.

steve
Anonymous
August 7, 2005 12:52:03 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Cockpit Colin wrote:
>>I use a 50mm 1.4 lens for most portraits. This is roughly equal to the
>>75mm of a true portrait lens however...
>
>
> My kit lens maxes out at 50mm - but at this distance I've got the camera
> only about 1m from my subject - so I'm assuming that with a 85mm lens I'd be
> a touch under 2m, which should be fine - is this a valid assumption???
>
> The issue I'm having is getting the shutter speed high enough to freeze a
> moving subject while I fire off a burst of shots. Many may not like this
> approach - and no doubt I'll improve my technique - but what I'm after is
> portraits where the subject (ie daughter for now) isn't just smiling, but is
> "squealing with delight" - only way I've found to get the ones I want is to
> take a burst whilst I make her laugh - but at F5.6 (even under strong
> lights) my shutter speeds are waaaaay too slow @ 100 ISO (I used to like the
> grain of higher ISOs, but soon discovered it's too much if the photo is
> being blown up). I'm gambling that a faster lens will make all the
> difference (even if I also have to use ISO 200 at a pinch). What I'm hoping
> to capture is something that'll be sharp when blown up to perhaps 150 to
> 200% and framed on a feature wall)
>
> I was getting excited about the 135mm F2.0 L lens - one of the reviews
> described it as "the perfect portrait lens" - but I didn't check what sort
> of camera he was using it with - probably safe to bet is wasn't with a 1.6
> crop factor camera :( 
>
> I'm leaning towards the 85mm F1.2 L - I really don't know what I'll think of
> the DOF - but I think it'll give me the most options (can always stop down
> for better DOF) - and for portraits it sounds like it's a safer bet @ 85mm.
> I'll probably get the other one as well - it sounds like it would be a good
> choice for trips around the zoo.
>

Let your speedlight be your friend.
Set your camera's custom function to allow your speedlight to use
1/250th in Av mode. The luminance will be enough to light the subject
correctly with one shot and you can pretty much choose whatever aperture
you like within reasonable bounds, based on the depth of field you plan
to have and the output power of your speedlight.

If it sound like it won't work, consider the speedlight in ETTL II mode
will modify it's output strength and communicate to the camera to suit
the scene. It works quite well indoors. Outside is another kettle of fish.

The earlier poster who commented on one eye being out of focus when the
other is not, demonstrated why it is crucial in portraiture to either
see a stopped down preview or know your gear well enough to be able to
look at a shot and know what f stop will be needed to achieve the depth
of field you want.

Just keep in mind that whatever DOF you would have at the lenses FL (say
50mm), the same lens on a digital will 'look' like it's a 75 mm but have
the DOF of the 50 mm lens. The 1.6 crop factor is cropping the image,
not magnifying it.

f5.6 is the (Canon) digital equal to f8 in full frame and is what
eminent flash makers like Metz, recommend for a starting point in
portraiture. To use apertures wider than f5.6, you really need to know
what you are going to get. The purpose of a fast lens is not so much to
take impossibly shallow shots but to be able to see and focus with them.

Like having a 7 litre V8 engine. It is not supposed to use all it has
all the time. Same with fast lenses!

--
Douglas,
You never really make it on the 'net
until you get your own personal Troll.
Mine's called Chrlz. Don't feed him, he bites!
August 7, 2005 1:28:08 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

> I'm getting close to purchasing my first Canon L series lens for portrait
> work - every review I've read suggests that the 85mm F1.2 L is a real
> honey - but I've also read better reviews of the 135mm F2.0 L series.
>
> Today I've had a bit of a play with an online DOF calculator and if what
I'm
> reading is correct then I suspect that I'm never going to be able to use
it
> wider than 2.0 because the DOF range is so small we're getting to a point
> where if the eyes are in focus then the tip of the nose will be out, and
the
> ears waaay out. I'm curious as to what you good folks feel is the minimum
> F-Stop (ie largest aperture) for portrait work?
>
> Also, am I correct in assuming that if I presently position my camera
approx
> 1m away from my subject with a 50mm lens then I'll have to be at 2.7m with
a
> 135mm?
>

Its an artistic choice, but it seems a hallmark high volume low cost to have
everything in focus, including the texture of the background, and many
portrait photogs use the shallowest f/no they can.

I used to shoot a 4x5 wide open with a DOF so shallow that only one eye was
in focus. Lots of old hollywood images were like this.
Anonymous
August 7, 2005 3:09:08 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Pixby <pixby_douglas@hotmail.com> wrote:

>Depth of field for a digital camera is a hell of a lot greater than with
>film SLR.


Nonsense.

Depth of field for the Canon EOS 1Ds is the same as with 35mm film.

**Exactly** the same.

Why? Because depth of field depends on the sensor size, not whether
that sensor is digital or film.
Anonymous
August 7, 2005 3:09:09 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Tony Polson wrote:

> Why? Because depth of field depends on the sensor size, not whether
> that sensor is digital or film.

It actually has to do with the ratio of print size to sensor size, focal
length, aperture and focus distance.

But thanks for playing.

;-)

Cheers,
Alan.
--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: Remove FreeLunch.
Anonymous
August 7, 2005 1:23:30 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

David Littlewood wrote:
> In article <42f460cf$1@dnews.tpgi.com.au>, Pixby
> <pixby_douglas@hotmail.com> writes
>
>>
>> There is such a thing described in almost every book on the subject of
>> portraits as "the perspective of a portrait". Some techno geek from
>> the frozen wastes of Canada told me perspective is not tied to focal
>> length. For a portrait it is. He is yet to show me his "traditional
>> portrait" taken with a 14mm lens. (Douglas sniggers quietly)
>
>
> Well, the "geek" was (mostly) right and you were (mostly) wrong.
> Distance perspective* is determined purely by distance. If you take a
> picture from a set distance with a wide and a tele, and crop and enlarge
> the wide shot to cover the same area, the two will be identical
> (ignoring pixellation and any other resolution effects).
>

The problem here David is interpretation of wording applying to
different industries. The optical industry will go along with the notion
that perspective does not change with focal length - despite them making
variable perspective lenses.

Photographers and artists will know absolutely they can't take a
portrait photo which "looks" right unless they get the perspective
right. Standing well back from the subject and altering the angle of
view, will do this.

You simply can't get correct perspective of a portrait, with an 8 mm
lens so the whole picture which needs the right perspective is tied to
the focal length of a lens which will let you get that perspective. This
is about photography and art, not about the mechanics of tools used to
make a portrait. They can be anything from a chisel to a camera.

Artists who use cameras might not know the absolute last detail about
the mechanical design of their equipment - and nor should they need to,
the camera is just a tool - but they sure as hell know about perspective
in portraiture. If I didn't have a camera, I would sketch my portraits
and colour them with paint. All my portraits have a pleasant perspective
to them, regardless of whether I used an optical lens on a camera or my
eye and charcoal.

It is a well established description to refer to "a better perspective
to a portrait by using a telephoto lens". It is not my wording but from
an eminent portrait photographer responsible for several textbooks and
manuals on the subject.

The fact you have to move further away from your subject to use a
telephoto lens is secondary to the intent of the sentence. Using a
telephoto lens to take a Portrait, *forces* you to change the
perspective. "By what ever means you use to achieve the end result, the
process shall be known".

If you know who wrote that and when it was written, I will alter my
opinion of you as being a geek with a camera and not a photographer.

--
Douglas,
You never really make it on the 'net
until you get your own personal Troll.
Mine's called Chrlz. Don't feed him, he bites!
August 7, 2005 1:23:31 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Pixby <pixby_douglas@hotmail.com> wrote in
news:42f5468b@dnews.tpgi.com.au:

> David Littlewood wrote:
>> In article <42f460cf$1@dnews.tpgi.com.au>, Pixby
>> <pixby_douglas@hotmail.com> writes
>>
>>>
>>> There is such a thing described in almost every book on the subject
>>> of portraits as "the perspective of a portrait". Some techno geek
>>> from the frozen wastes of Canada told me perspective is not tied to
>>> focal length. For a portrait it is. He is yet to show me his
>>> "traditional portrait" taken with a 14mm lens. (Douglas sniggers
>>> quietly)
>>
>>
>> Well, the "geek" was (mostly) right and you were (mostly) wrong.
>> Distance perspective* is determined purely by distance. If you take a
>> picture from a set distance with a wide and a tele, and crop and
>> enlarge the wide shot to cover the same area, the two will be
>> identical (ignoring pixellation and any other resolution effects).
>>
>
> The problem here David is interpretation of wording applying to
> different industries. The optical industry will go along with the
> notion that perspective does not change with focal length - despite
> them making variable perspective lenses.
>
> Photographers and artists will know absolutely they can't take a
> portrait photo which "looks" right unless they get the perspective
> right. Standing well back from the subject and altering the angle of
> view, will do this.

As will standing in the same place and taking the same picture with a
wider lens, then cropping the image to produce the same picture as you
would have gotten with a longer lens.

> You simply can't get correct perspective of a portrait, with an 8 mm
> lens so the whole picture which needs the right perspective is tied to
> the focal length of a lens which will let you get that perspective.
> This is about photography and art, not about the mechanics of tools
> used to make a portrait. They can be anything from a chisel to a
> camera.

I think that you can, especially if you use a small sensor digital
camera that gives the same FoV with the 8mm as you would normally get
with a 40mm lens on a 35mm camera. As long as you stand in the right
place you will get the right perspective.

> It is a well established description to refer to "a better perspective
> to a portrait by using a telephoto lens". It is not my wording but
> from an eminent portrait photographer responsible for several
> textbooks and manuals on the subject.
>
> The fact you have to move further away from your subject to use a
> telephoto lens is secondary to the intent of the sentence. Using a
> telephoto lens to take a Portrait, *forces* you to change the
> perspective. "By what ever means you use to achieve the end result,
> the process shall be known".

The fact you have to move further away from your subject to use a
telephoto lens is primary to the intent of the sentence. It is 100% the
point of the sentence. The eminent portrait photographer wants you to
stand further back to get a better perspective, he knows that telling
you to use a telephoto lens will automatically get you to stand in the
right place without even thinking about it.

Surely if the same books had decided to explain that the "better
perspective" would be achieve by being further from the model and that
to get the right picture at that distance you would use a longer lens,
then it would have been just as correct? If a book said that changing
to an 80mm lens instead of a 50mm lens would mean that you would stand
further back and that standing further back would provide a better
perspective, isn't that simply a fuller explanation of "a longer lens
gives a better perspective"

What I am saying is that the books don't fully explain what they mean
and that "a longer lens gives a better perspective" is not true unless
you understand that they actually mean "standing furter away with a
longer lens gives a better perspective". They simply assume (fairly
accurately) that a photographer with a longer tele lens will naturally
stand further back. It is a case of explaining what to do, not how it
works.

If I am writing a book and want to explain to the readers that they need
to stand further back to get the right perspective I could tell them to
use a tape measure and stand a certain distance, but they will keep
moving to the distance that frames the subject the way they want. If my
goal is to get them to stand further back then the simplest way to
achieve that goal is to have them shoot with a longer lens. Why make
things complicated and tell people to measure the width of the face and
then calculate how far back to stand to get the perspective right, when
they could shoot with a 135mm lens and stand in the right place without
measuring, calculating or even consciously thinking about where to
stand?


--
Mark Heyes (New Zealand)
See my pics at www.gigatech.co.nz (last updated 25-June-05)
"There are 10 types of people, those that
understand binary and those that don't"
Anonymous
August 7, 2005 4:39:42 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

MarkH <markat@atdot.dot.dot> wrote:
>
>The fact you have to move further away from your subject to use a
>telephoto lens is primary to the intent of the sentence. It is 100% the
>point of the sentence. The eminent portrait photographer wants you to
>stand further back to get a better perspective, he knows that telling
>you to use a telephoto lens will automatically get you to stand in the
>right place without even thinking about it.
>
>Surely if the same books had decided to explain that the "better
>perspective" would be achieve by being further from the model and that
>to get the right picture at that distance you would use a longer lens,
>then it would have been just as correct? If a book said that changing
>to an 80mm lens instead of a 50mm lens would mean that you would stand
>further back and that standing further back would provide a better
>perspective, isn't that simply a fuller explanation of "a longer lens
>gives a better perspective"
>
>What I am saying is that the books don't fully explain what they mean
>and that "a longer lens gives a better perspective" is not true unless
>you understand that they actually mean "standing furter away with a
>longer lens gives a better perspective". They simply assume (fairly
>accurately) that a photographer with a longer tele lens will naturally
>stand further back. It is a case of explaining what to do, not how it
>works.
>
>If I am writing a book and want to explain to the readers that they need
>to stand further back to get the right perspective I could tell them to
>use a tape measure and stand a certain distance, but they will keep
>moving to the distance that frames the subject the way they want. If my
>goal is to get them to stand further back then the simplest way to
>achieve that goal is to have them shoot with a longer lens. Why make
>things complicated and tell people to measure the width of the face and
>then calculate how far back to stand to get the perspective right, when
>they could shoot with a 135mm lens and stand in the right place without
>measuring, calculating or even consciously thinking about where to
>stand?


Well said.

What is patently obvious is that Doug (Ryadia, Pixby ... etc.) simply
doesn't understand perspective.

Pearls before swine ...

;-)
Anonymous
August 7, 2005 4:39:43 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Tony Polson wrote:
[]
> What is patently obvious is that Doug (Ryadia, Pixby ... etc.) simply
> doesn't understand perspective.

Or don't share your viewpoint....
<G>
Anonymous
August 7, 2005 4:45:19 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In article <42f5468b@dnews.tpgi.com.au>, Pixby
<pixby_douglas@hotmail.com> writes
>David Littlewood wrote:
>> In article <42f460cf$1@dnews.tpgi.com.au>, Pixby
>><pixby_douglas@hotmail.com> writes
>>
>>>
>>> There is such a thing described in almost every book on the subject
>>>of portraits as "the perspective of a portrait". Some techno geek
>>>from the frozen wastes of Canada told me perspective is not tied to
>>>focal length. For a portrait it is. He is yet to show me his
>>>"traditional portrait" taken with a 14mm lens. (Douglas sniggers quietly)
>> Well, the "geek" was (mostly) right and you were (mostly) wrong.
>>Distance perspective* is determined purely by distance. If you take a
>>picture from a set distance with a wide and a tele, and crop and
>>enlarge the wide shot to cover the same area, the two will be
>>identical (ignoring pixellation and any other resolution effects).
>>
>
>The problem here David is interpretation of wording applying to
>different industries. The optical industry will go along with the
>notion that perspective does not change with focal length - despite
>them making variable perspective lenses.
>
>Photographers and artists will know absolutely they can't take a
>portrait photo which "looks" right unless they get the perspective
>right. Standing well back from the subject and altering the angle of
>view, will do this.
>
>You simply can't get correct perspective of a portrait, with an 8 mm
>lens so the whole picture which needs the right perspective is tied to
>the focal length of a lens which will let you get that perspective.
>This is about photography and art, not about the mechanics of tools
>used to make a portrait. They can be anything from a chisel to a camera.
>
>Artists who use cameras might not know the absolute last detail about
>the mechanical design of their equipment - and nor should they need to,
>the camera is just a tool - but they sure as hell know about
>perspective in portraiture. If I didn't have a camera, I would sketch
>my portraits and colour them with paint. All my portraits have a
>pleasant perspective to them, regardless of whether I used an optical
>lens on a camera or my eye and charcoal.
>
>It is a well established description to refer to "a better perspective
>to a portrait by using a telephoto lens". It is not my wording but from
>an eminent portrait photographer responsible for several textbooks and
>manuals on the subject.
>
>The fact you have to move further away from your subject to use a
>telephoto lens is secondary to the intent of the sentence. Using a
>telephoto lens to take a Portrait, *forces* you to change the
>perspective. "By what ever means you use to achieve the end result, the
>process shall be known".
>
>If you know who wrote that and when it was written, I will alter my
>opinion of you as being a geek with a camera and not a photographer.
>
I find it quite odd that you type a whole page trying to disagree with
me, but pretty well everything you actually say is in line with what I
said in the first place. Having made an error in wording in your first
post, you now try to say, "well the words I used are sometimes used by
others to apply to the facts as you described them".

For the avoidance of doubt, perspective is determined by position, not
by focal length directly, though focal length may itself dictate a
position and thus indirectly affect perspective. You seem to agree with
this, so why the implied criticism?

I don't know what you mean by "variable perspective lenses".

I probably won't see your reply, as I am off to Italy for 10 days in an
hour or so, and any follow up will almost certainly have expired before
I return. However, I have to say that forming an opinion of another
person based on an almost total lack of knowledge does not impress.
--
David Littlewood
Anonymous
August 7, 2005 5:09:45 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

"David J Taylor"
<david-taylor@blueyonder.co.not-this-bit.nor-this-part.uk.invalid>
wrote:

>Tony Polson wrote:
>[]
>> What is patently obvious is that Doug (Ryadia, Pixby ... etc.) simply
>> doesn't understand perspective.
>
>Or don't share your viewpoint....
><G>


Since viewpoint uniquely defines perspective, obviously not.

;-)
August 8, 2005 2:14:11 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Pixby wrote:

> Cockpit Colin wrote:

> Depth of field for a digital camera is a hell of a lot greater than with
> film SLR. That having been said, the focal length previously considered
> in 35 mm circles to be a "portrait lens" is too long for digital with a
> 1.6 crop factor. This is 75mm to 90mm, depending on the maker.
>
The difference for APS-C is about 1 stop:
75mm at f2.8 with 35mm =
50mm at f2 with 1:1.5 ratio crop
Same DOF almost exactly (not that 1 stop is a big difference anyway).
A "hell of a lot greater" is comparing either of the above to a P&S
camera with a small sensor.
Anonymous
August 8, 2005 4:32:11 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

"David Littlewood" <david@nospam.demon.co.uk> wrote in message
news:+5hVQeG5RM9CFw$x@dlittlewood.co.uk...
> Then your lighting is inadequate. In bright sunlight you should get 1/500
> to 1/800 for f/5.6 at ISO 100 (depending on what latitude you are at). If
> you are inside, try using flash.

I'm using 2000 watts of halogen - do I need more????
Anonymous
August 8, 2005 4:32:12 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

In message <gbnJe.1022$iM2.73716@news.xtra.co.nz>,
"Cockpit Colin" <spam@nospam.com> wrote:

>"David Littlewood" <david@nospam.demon.co.uk> wrote in message
>news:+5hVQeG5RM9CFw$x@dlittlewood.co.uk...
>> Then your lighting is inadequate. In bright sunlight you should get 1/500
>> to 1/800 for f/5.6 at ISO 100 (depending on what latitude you are at). If
>> you are inside, try using flash.

>I'm using 2000 watts of halogen - do I need more????

With halogen or tungsten, you are always weak in the blue channel,
unless you filter the light or the lens.

--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
Anonymous
August 8, 2005 4:48:30 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Thanks everyone for the good advice - I think photography must be one of
those disciplines in life where "the more you learn the more you realise how
much you have to learn!"

Perhaps I should give up on portraits and go for nudes instead - Hmmm -
would probably need a super-wide-angle lens for that!
August 8, 2005 4:48:31 AM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Cockpit Colin wrote:
> Thanks everyone for the good advice - I think photography must be one of
> those disciplines in life where "the more you learn the more you realise how
> much you have to learn!"
>
> Perhaps I should give up on portraits and go for nudes instead - Hmmm -
> would probably need a super-wide-angle lens for that!
>
>


Depends on the broad nature of your subjects, no?


(sowwy, couldn't resist)

--
jer
email reply - I am not a 'ten'
Anonymous
August 8, 2005 1:20:34 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Broadly speaking ...

That's probably the difference between a pro and an amatuer - the pro uses a
portrait lens and gets paid for photographing stunning nude models - the
amatuer has to pay for it, and then has to use a wide angle lens to "fit
everything in" :( 

Oh to be a PROFESSIONAL photographer!!
August 8, 2005 1:20:35 PM

Archived from groups: rec.photo.digital.slr-systems (More info?)

Cockpit Colin wrote:
> Broadly speaking ...
>
> That's probably the difference between a pro and an amatuer - the pro uses a
> portrait lens and gets paid for photographing stunning nude models - the
> amatuer has to pay for it, and then has to use a wide angle lens to "fit
> everything in" :( 
>
> Oh to be a PROFESSIONAL photographer!!
>
>


ROFLMAO! Which means I better get a fisheye first thing tomorrow. :) 

--
jer
email reply - I am not a 'ten'
!