Why Fuss Over Lens Bokeh?

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

A buddy of mine posed an interesting question to me, and while I think
I have some of the answer, thought I'd pose it to the group. Why is
lens bokeh perceived as important in the digital world? His point was
it's very easy to add almost any type/quality of blur using PS. He
argues you should shoot sharper than ultimately needed and then add
blur in post-processing. This gives you the ability to choose where
the blur begins and how much you have and at what rate it changes using
a layer mask with a gradient. He concedes that in some cases it can be
hard to do in post processing because of complex foreground and
background relationships, but in almost every case where there's a
single foreground object, PS allows for amazing control, etc. - far
more than a lens ever can.

Thoughts?

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

Tony Polson wrote:

>
>
> If you think you can use Photoshop to reproduce the effect of smooth
> bokeh in a shot taken with a lens that has harsh bokeh, you have a
> promising career ahead of you ...
>
> ... selling snake oil. I wish you luck.
>


Yeah, that was my point too. :-)

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

<briansgooglegroupemail@yahoo.com> wrote:

> Why is lens bokeh perceived as important in the digital world?

For the same reason sharpness is perceived as important in the digital
world.

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

<briansgooglegroupemail@yahoo.com> wrote in message
news:1117214260.807448.194810@z14g2000cwz.googlegroups.com...
>
> A buddy of mine posed an interesting question to me, and while I think
> I have some of the answer, thought I'd pose it to the group. Why is
> lens bokeh perceived as important in the digital world? His point was
> it's very easy to add almost any type/quality of blur using PS. He
> argues you should shoot sharper than ultimately needed and then add
> blur in post-processing. This gives you the ability to choose where
> the blur begins and how much you have and at what rate it changes using
> a layer mask with a gradient. He concedes that in some cases it can be
> hard to do in post processing because of complex foreground and
> background relationships, but in almost every case where there's a
> single foreground object, PS allows for amazing control, etc. - far
> more than a lens ever can.
>
> Thoughts?
>

Often when people say they have a friend who wants to ask a question, they
are really protecting themselves - you, or your "friend" dont need to answer
that.

I've tried and _seen_ PS bokehs and they look horrible. If you have a link
of a good one, I would be interested. The bokeh is also a function of
aperture blade construction and hence it would be difficult to mimick this
with say a gaussian blur. Some of us on this NG pay damn good money to have
pictures with things as much out of focus as possible - strange isn't it?

Musty.

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

BTW, I think he's copping out now, saying my parameters are difficult
to PS.

Figures.


briansgooglegroupem...@yahoo.com wrote:
> Musty wrote:
> >
> > Often when people say they have a friend who wants to ask a question, they
> > are really protecting themselves - you, or your "friend" dont need to answer
> > that.
>
> Heh, actually we're having an ongoing email discussion about it in
> parallel with this thread. I just sent him a shot of a flower behind
> some foreground leaves and with other flowers and plants behind it
> taken at f/20. I'm also keeping another pic of the same scene to
> myself that I shot at f/2. He's gonna photoshop the f/20 one and then
> we'll compare. It'll be interesting. In any event, I'm not good
> enough with photoshop to do a good job at it. But he thinks he is.
>
>
> > I've tried and _seen_ PS bokehs and they look horrible. If you have a link
> > of a good one, I would be interested. The bokeh is also a function of
> > aperture blade construction and hence it would be difficult to mimick this
> > with say a gaussian blur. Some of us on this NG pay damn good money to have
> > pictures with things as much out of focus as possible - strange isn't it?
>
> If his looks good, I'll post it. I told him that one requirement is
> that it must not look photoshopped.

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

>BTW, I think he's copping out now, saying my parameters
>are difficult to PS.
>
>Figures.

Do the world a favour, and make him say the words 'I was wrong'. There
are too many folk around that just can't bring themselves to admit they
don't know everything, and they cause a lot of trouble...



And of course they are quite annoying to those of us who *do* know
everything...

(O;

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

Tony Polson wrote:

> "Musty" <musty@nospam.net> wrote:
>
>>The bokeh is also a function of
>>aperture blade construction and hence it would be difficult to mimick this
>>with say a gaussian blur.
>
>
> Bokeh has nothing whatsoever to do with "aperture blade construction".
>


Exactly. I have some old LF lenses with like 36 blades that still have some
nasty looking bokeh and other lenses with much fewer like a CZJ 180mm sonar
that has bokeh that is smooth as butter. Also the BS about 'sharp lenses
have bad bokeh' is wrong as this sonar is deadly sharp even wide open.
--

Stacey

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

On 27 May 2005 10:17:40 -0700, briansgooglegroupemail@yahoo.com wrote:

>
>A buddy of mine posed an interesting question to me, and while I think
>I have some of the answer, thought I'd pose it to the group. Why is
>lens bokeh perceived as important in the digital world? His point was
>it's very easy to add almost any type/quality of blur using PS. He
>argues you should shoot sharper than ultimately needed and then add
>blur in post-processing. This gives you the ability to choose where
>the blur begins and how much you have and at what rate it changes using
>a layer mask with a gradient. He concedes that in some cases it can be
>hard to do in post processing because of complex foreground and
>background relationships, but in almost every case where there's a
>single foreground object, PS allows for amazing control, etc. - far
>more than a lens ever can.
>

It's not restricted to the digital world. It started with film. And I
defy you or anyone the produce the boke, one can get out of a Canon
135mm F2.0L in Photoshop.


****************************************************

"The booksellers are generous liberal-minded men."

Samuel Johnson
"Life of Johnson" (J. Boswell), Vol. I, 1756

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

On 27 May 2005 10:17:40 -0700, briansgooglegroupemail@yahoo.com wrote:

>
>A buddy of mine posed an interesting question to me, and while I think
>I have some of the answer, thought I'd pose it to the group. Why is
>lens bokeh perceived as important in the digital world? His point was
>it's very easy to add almost any type/quality of blur using PS. He
>argues you should shoot sharper than ultimately needed and then add
>blur in post-processing. This gives you the ability to choose where
>the blur begins and how much you have and at what rate it changes using
>a layer mask with a gradient. He concedes that in some cases it can be
>hard to do in post processing because of complex foreground and
>background relationships, but in almost every case where there's a
>single foreground object, PS allows for amazing control, etc. - far
>more than a lens ever can.

This may help you and your buddy understand this better and why it's
not like what you can do in Photoshop?

http://www.luminous-landscape.com/essays/bokeh.shtml

http://www.luminous-landscape.com/ [...] 4-04.shtml


****************************************************

"The booksellers are generous liberal-minded men."

Samuel Johnson
"Life of Johnson" (J. Boswell), Vol. I, 1756

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

Toby wrote:
> <briansgooglegroupemail@yahoo.com> wrote in message
> news:1117214260.807448.194810@z14g2000cwz.googlegroups.com...
>>
>> A buddy of mine posed an interesting question to me, and while I
>> think I have some of the answer, thought I'd pose it to the group.
>> Why is lens bokeh perceived as important in the digital world? His
>> point was it's very easy to add almost any type/quality of blur
>> using PS. He argues you should shoot sharper than ultimately
>> needed
>> and then add blur in post-processing. This gives you the ability
>> to
>> choose where the blur begins and how much you have and at what rate
>> it changes using a layer mask with a gradient. He concedes that in
>> some cases it can be hard to do in post processing because of
>> complex foreground and background relationships, but in almost
>> every
>> case where there's a single foreground object, PS allows for
>> amazing
>> control, etc. - far more than a lens ever can.
>>
>> Thoughts?
>>
>
> It's not so simple: bokeh refers to the look of out-of-focus parts
> of
> the image, but that isn't constant, it depends on how o-o-f a given
> area actually is. PS can add any kind of blur you fancy, but it
> can't
> add it selectively depending on how o-o-f an area is--it can only
> apply it globally, so you are going to have a big job manually
> appling different amounts of blur to different parts of the image.
> In
> any case since elements overlap you will never be able to reproduce
> the effect of bokeh accurately post-capture.
>
> Toby

Do I hear the sound of an enterprising programmer with artsy
tendencies thinking, "Aha! _Genuine_ _Bokeh_! I'll be rich and
famous!"

--
Frank ess

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

Stacey wrote:

> Alan Brownbe wrote:
>
>
>>briansgooglegroupemail@yahoo.com wrote:
>>
>>>it's very easy to add almost any type/quality of blur using PS. He
>>>argues you should shoot sharper than ultimately needed and then add
>>>blur in post-processing. This gives you the ability to choose where
>>
>>Fundamental misubnderstanding of out of focus areas.
>>
>>First off, an image is a 2D rendering of a projection from a 3D world.
>>
>>OOF areas can't be 'sharp' they are out of focus. They should ideally
>>be smooth and creamy. Many very sharp lenses render highlights in the
>>out-of-focus area harshly.
>>
>
>
> Lens sharpness has next to nothing to do with the rendering of OOF parts of
> the image.

That's essentially what I was saying. For example, many of Nikons
exceptionally sharp lenses have harsh bokeh.

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.

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

Chrlz wrote:

> And of course they are quite annoying to those of us who *do* know
> everything...

Congratulations.

I missed my certification when they asked "what is the answer to
everything" and I replied "24".

Damned dylsexia!

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.

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

Paul Furman <paul-@-edgehill.net> wrote:
> Alan Browne wrote:
>
>> many of Nikons exceptionally sharp lenses have harsh bokeh.
>
> Did I read above that the 50mm f/1.8 has bad bokeh? I thought that was
> the best feature of those?

I wouldn't call it bad. I shoot wide open with mine almost exclusively
(well, sometimes I stop down to f/2) and have no problem with it, even
though it's not as outstanding as a much more expensive lens might give.

I think the "bokeh" (ghod, I hate that word) on the 50/1.4 is better when
used wide open -- but not better enough to get me to replace my 1.8 with
it at 3x the price or so, at least not quite yet. (Though I do have a
manual 50/1.2 for when I need the speed; if I didn't, I probably would
have gone for the 1.4 by now.)

> Or was it just that they have octaganal shaped highlights when there is
> a high contrast highlight but otherwise soft & creamy.

Highlights are actually quite round at f/1.8. Probably not so much when
stopped down, but I can't find any pictures in my collection taken with
this lens stopped down with out of focus highlights.

Here's a good example of out of focus highlights with the 50/1.8, at
f/1.8 (D70, ISO 640):

http://www.exit109.com/~jeremy/nopictures.jpg

The 85/1.4 it ain't, but I don't think it's bad.

> I might look at a 35mm fast model if that might do better since it'd be
> more 'normal' on a D70.

If you like "zero depth of field" type shots, the 35mm f/2 won't get you
there; it's a nice lens, but does give a lot more depth of field than a
50mm. There is a manual focus 35mm f/1.4, which I have never used, that
might be reasonable. Except in price, which is a bit high.

--
Jeremy | jeremy@exit109.com

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

Paul Furman <paul-@-edgehill.net> wrote:

> Hmm that's a darn obvious donut ring effect on the strongest highlights.
> I guess those are really strong highlights though.

Yep; that's why I picked that example, it shows it as bad as it will ever
get. Point light sources with very high contrast, and the hardness of the
edges of the circles is apparent. If your out of focus areas aren't point
light sources at night, they won't be nearly as bad (as you can see in the
other areas) but as you can tell it won't be the ultimate creamy soft-edged
circles. But at least they are circles, not octagons or whatever.

The thing is, the lens is so cheap you can buy it on a whim, and that counts
for a lot. It's also, all around, a top-quality lens.

[35mm]
> $600 is more than I'd spend on a 'normal' lens & I don't have a deep
> craving for extreme blur. I was thinking of the f/2 for $300.

I picked it up used for about half that. But it usually goes for more on
eBay, so I had to be patient and "lose" several auctions before I got it
at the price I wanted to pay.

> Interesting that the 35 f/2 is good for closeups too.

It focuses very close, yes, less than a foot I think.

> Hmm, but it looks like the 50 f/1.4 is about the same price and is
> supposed to have equisite OOF quality.

The 1.4 is better wide open than the 1.8, yes. I haven't seen it described
in gushing terms, but I have heard that it's better. Someday I'm sure I'll
upgrade.

> I couldn't find any review specifically mentioning the bokeh of the
> 35 f/2.

I'm trying to find a good example... damn iView MediaPro for lacking
search ability on the one field I want right now, focal length.

Ah, here we go. Not a great shot (he turned out not to want his picture
taken, so I didn't get his face) but it has both out-of-focus foreground
and background:

http://www.exit109.com/~jeremy/streetfood.jpg

That's shot with the 35/2 at f/2. As you can see, there's much more
depth of field than you get with a 50mm at close range.

--
Jeremy | jeremy@exit109.com

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

BC wrote:


>
> Another example which even you wouldn't refute is that of catadioptric
> lenses with a central obscuration. These are well known to have just
> about the worst bokeh of any lens, and the effect is 100% due to the
> donut shape of the aperture stop. The optical design of the lens
> simply does not play a role here.
>


Maybe then you can explain who so many lenses have AWFUL bokeh when shot
wide open, when the aperture is perfectly round? The 180mm f2.8 sonar has
sopme of the smoothest bokeh around yet has no more blades than the nikons
you speak of.
--

Stacey

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

In article <Wd1me.13090$6g3.7794@tornado.texas.rr.com>,
Musty <musty@nospam.net> wrote:
>So based on what you just said eventually, bokeh is a function of aperture
>construction (you just said that the aperture can made bad bokeh slightly
>less obvious). Just the fact that the bokeh generating light rays pass
>though the aperture makes it a function of this variable (on top of all the
>other variables that generate the bokeh function). In other words what I am
>saying is:

It is true that point light sources are strongly influenced by the shape
of the aperture when they are rendered out of focus.

However, point light sources tend to be quite rare in many categories of
photography. Typical subjects that include point light sources are
street lights and reflections from a camera mounted flash.
Larger features in background are not nearly as much influenced by the
shape of the aperature as point light sources.

Furthermore, when a lens is wide open, the aperture tends to be round.

So when it comes to bokeh, the important part is the optical contruction
of the lens.

It is only when you shoot point light source and you can't affort to have
the lens wide open, that the shape of the aperture becomes an issue.

>The final captured bokeh is affected (and is thus a function of) the
>aperture design. Even Canon claim the same thing when advertising some of
>their lenses. Besides this, its bloody obvious that the light path effects
>the light.

Larger features with moderate contrast are not all that much influenced
by the shape of the aperture. If you shoot for example portrets then there
is good chance that you don't need any kind of special aperture provided
that the optical contruction of the lens has good (smooth) bokeh.


--
That was it. Done. The faulty Monk was turned out into the desert where it
could believe what it liked, including the idea that it had been hard done
by. It was allowed to keep its horse, since horses were so cheap to make.
-- Douglas Adams in Dirk Gently's Holistic Detective Agency

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

On Sat, 28 May 2005 17:56:48 -0400, Stacey <fotocord@yahoo.com> wrote:

>Alan Browne wrote:
>
>> Stacey wrote:
>>
>>> Alan Brownbe wrote:
>>>
>>>
>>>>briansgooglegroupemail@yahoo.com wrote:
>>>>
>>>>>it's very easy to add almost any type/quality of blur using PS. He
>>>>>argues you should shoot sharper than ultimately needed and then add
>>>>>blur in post-processing. This gives you the ability to choose where
>>>>
>>>>Fundamental misubnderstanding of out of focus areas.
>>>>
>>>>First off, an image is a 2D rendering of a projection from a 3D world.
>>>>
>>>>OOF areas can't be 'sharp' they are out of focus. They should ideally
>>>>be smooth and creamy. Many very sharp lenses render highlights in the
>>>>out-of-focus area harshly.
>>>>
>>>
>>>
>>> Lens sharpness has next to nothing to do with the rendering of OOF parts
>>> of the image.
>>
>> That's essentially what I was saying. For example, many of Nikons
>> exceptionally sharp lenses have harsh bokeh.
>>
>
>Good grief, you contradicted yourself from one sentance to the next or you
>can't read.
>
>And no Alan sharpness has NOTHING to do with how the OOF parts are rendered.
>There are some "exceptionally sharp" lenses like the zeiss planar and sonar
>that also have creamy smooth bokeh. Many of the jap lens makers focused on
>sharpness and ignore bokeh altogether so I guess if all you've used are
>these, you might jump to this assumption?

*********************************************************

"I have been a witness, and these pictures are
my testimony. The events I have recorded should
not be forgotten and must not be repeated."

-James Nachtwey-
http://www.jamesnachtwey.com/

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

Paul Furman <paul-@-edgehill.net> wrote:

>Alan Browne wrote:
>>
>> many of Nikons
>> exceptionally sharp lenses have harsh bokeh.
>
>Did I read above that the 50mm f/1.8 has bad bokeh? I thought that was
>the best feature of those? Or was it just that they have octaganal
>shaped highlights when there is a high contrast highlight but otherwise
>soft & creamy. I might look at a 35mm fast model if that might do better
>since it'd be more 'normal' on a D70.


The Nikon 50mm f/1.8 Series E, AIS, AF and AF-D versions are all
optically similar. They have just about the harshest bokeh of any
Nikon lenses ever made. They appear to have been over-corrected to
achieve high MTF at the expense of bokeh.

If you want smooth bokeh, Nikon have almost no lenses in the 35mm and
50mm focal lengths that will fit the bill. The only Nikon 50mm lenses
known to have acceptable bokeh are earlier AI and pre-AI designs. The
50mm f/1.8 AI that preceded the AIS is not bad. I used a pre-AI 50mm
f/1.4 which wasn't bad.

I believe that Gordon Moat, whose views I greatly respect, found a
50mm f/1.4 AIS with smooth bokeh but only after trying four other
examples that had harsh bokeh. I admire his tenacity. I wouldn't
want to have to rely on sample variation to find a lens that performed
acceptably well.

Nikon make claims that their careful attention to the shape of the
iris diaphragm opening improves the appearance of out of focus
highlights. Some recent Nikon lenses have used a greater number of
blades and/or fitted blades with curved edges.

Unfortunately, all this does is make the out-of-focus highlights look
round instead of shaped like a polygon. It doesn't change the bokeh
one bit. The highlights still look bright at the edges, making them
obtrusive.

Bokeh is purely a function of the optical design, specifically the
degree of correction of spherical aberration. All other things being
equal, a greater degree of correction of spherical aberration gives
better sharpness (and high MTF) but harsher bokeh. A lower degree of
correction of spherical aberration gives less sharpness (and lower
MTF) but smoother bokeh.

The trick is to achieve better effective sharpness without ruining the
bokeh. Broadly speaking, this is best achieved by improving contrast,
which is one of the two factors that define apparent sharpness, the
other being resolution. So better contrast can improve sharpness
while still retaining good bokeh. You really can have it both ways.

Most lens manufacturers have achieved this in at least some of their
lenses. Nikon has made the 85mm f/1.4 AI, AIS and AF-D, 105mm f/2.5
pre-AI, AI and AIS, 105mm and 135mm f/2 AF-D DC and the 180mm f/2.8
AI, AI-S, AF, AF-N and AF-D. All have superb bokeh. The humble
75-150mm f/3.5 Nikon Series E one-touch zoom has sublime bokeh. But
there's not much else in the Nikon range.

Most Pentax lenses have good bokeh, and some have a stunning,
ultra-smooth rendition of out of focus highlights, notably the much
sought-after SMC Pentax-A* 85mm f/1.4.

Some of the Olympus Zuiko Digital lenses for the Four Thirds system
have excellent bokeh. The 14-54mm, 50-200mm, 150mm f/2 and 50mm f/2
macro all have very good to excellent bokeh. The 50mm f/2 performs
much like the excellent Tamron 90mm f/2.8 macro does for 35mm and APS
digital. The zooms are remarkable performers - it is especially
difficult to design a zoom lens which renders smooth out of focus
highlights.

All Carl Zeiss lenses for Contax 35mm SLRs and the G Series have
excellent bokeh. Most Leica M lenses made before introduction of the
latest ASPH series have superb bokeh. The ASPHs are merely good in
that respect, but with truly outstanding sharpness - and distortion so
low that it isn't worth even trying to measure it. But their bokeh
has disappointed many Leica enthusiasts, to the point where used
examples of the last pre-ASPH versions of some Leica lenses are
selling at higher prices than the much newer ASPH versions.

Going back to the 1970s and early 1980s, Kiron of Japan made some
superb lenses that were sold under the Kiron and Vivitar brands. Alas
these will not meter on the D70 because Nikon did not enable the use
of pre-AF lenses. The can, however, be used on the D2Hs and D2X.

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

Stacey <fotocord@yahoo.com> wrote:
>
>Good grief, you contradicted yourself from one sentance to the next or you
>can't read.

Alan Browne has not the faintest understanding about bokeh, nor about
much else related to photography. He has repeatedly poured scorn on
those who do understand bokeh and its significance to photography, to
the point where he and another equally condescending friend "invented"
another word for it: "Schmuckle".

How appropriate: a term for schmucks who have no understanding!

http://www.aliasimages.com/Schmuckle.html

A more interesting reference of the word can be found here, and I
think the term "deviant" could not be more relevant to Mr Schmuck(le).

http://schmuckle.deviantart.com/

;-)

>And no Alan sharpness has NOTHING to do with how the OOF parts are rendered.
>There are some "exceptionally sharp" lenses like the zeiss planar and sonar
>that also have creamy smooth bokeh. Many of the jap lens makers focused on
>sharpness and ignore bokeh altogether so I guess if all you've used are
>these, you might jump to this assumption?

You're wasting your time, Stacey.

Leave Mr Schmuck(le) to concentrate on those little things he *really*
understands, such as the paramount importance of the "Rule" of Thirds
to creating thousands of mind-numbingly boring snapshots ...

.... otherwise known as "The Archive", to be submitted to the SI on
those occasions (90% of the Mandates) when Mr Schmuck(le) simply
cannot tear himself away from giving "advice" on his computer to go
outdoors and actually shoot something relevant.

;-)

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

On Sun, 29 May 2005 18:13:10 +0100, Tony Polson <tp@nospam.net> wrote:

>Paul Furman <paul-@-edgehill.net> wrote:
>
>>Alan Browne wrote:
>>>
>>> many of Nikons
>>> exceptionally sharp lenses have harsh bokeh.
>>
>>Did I read above that the 50mm f/1.8 has bad bokeh? I thought that was
>>the best feature of those? Or was it just that they have octaganal
>>shaped highlights when there is a high contrast highlight but otherwise
>>soft & creamy. I might look at a 35mm fast model if that might do better
>>since it'd be more 'normal' on a D70.
>
>
>The Nikon 50mm f/1.8 Series E, AIS, AF and AF-D versions are all
>optically similar. They have just about the harshest bokeh of any
>Nikon lenses ever made. They appear to have been over-corrected to
>achieve high MTF at the expense of bokeh.
>
>If you want smooth bokeh, Nikon have almost no lenses in the 35mm and
>50mm focal lengths that will fit the bill. The only Nikon 50mm lenses
>known to have acceptable bokeh are earlier AI and pre-AI designs. The
>50mm f/1.8 AI that preceded the AIS is not bad. I used a pre-AI 50mm
>f/1.4 which wasn't bad.
>
>I believe that Gordon Moat, whose views I greatly respect, found a
>50mm f/1.4 AIS with smooth bokeh but only after trying four other
>examples that had harsh bokeh. I admire his tenacity. I wouldn't
>want to have to rely on sample variation to find a lens that performed
>acceptably well.
>
>Nikon make claims that their careful attention to the shape of the
>iris diaphragm opening improves the appearance of out of focus
>highlights. Some recent Nikon lenses have used a greater number of
>blades and/or fitted blades with curved edges.
>
>Unfortunately, all this does is make the out-of-focus highlights look
>round instead of shaped like a polygon. It doesn't change the bokeh
>one bit. The highlights still look bright at the edges, making them
>obtrusive.
>
>Bokeh is purely a function of the optical design, specifically the
>degree of correction of spherical aberration. All other things being
>equal, a greater degree of correction of spherical aberration gives
>better sharpness (and high MTF) but harsher bokeh. A lower degree of
>correction of spherical aberration gives less sharpness (and lower
>MTF) but smoother bokeh.
>
>The trick is to achieve better effective sharpness without ruining the
>bokeh. Broadly speaking, this is best achieved by improving contrast,
>which is one of the two factors that define apparent sharpness, the
>other being resolution. So better contrast can improve sharpness
>while still retaining good bokeh. You really can have it both ways.
>
>Most lens manufacturers have achieved this in at least some of their
>lenses. Nikon has made the 85mm f/1.4 AI, AIS and AF-D, 105mm f/2.5
>pre-AI, AI and AIS, 105mm and 135mm f/2 AF-D DC and the 180mm f/2.8
>AI, AI-S, AF, AF-N and AF-D. All have superb bokeh. The humble
>75-150mm f/3.5 Nikon Series E one-touch zoom has sublime bokeh. But
>there's not much else in the Nikon range.
>
>Most Pentax lenses have good bokeh, and some have a stunning,
>ultra-smooth rendition of out of focus highlights, notably the much
>sought-after SMC Pentax-A* 85mm f/1.4.
>
>Some of the Olympus Zuiko Digital lenses for the Four Thirds system
>have excellent bokeh. The 14-54mm, 50-200mm, 150mm f/2 and 50mm f/2
>macro all have very good to excellent bokeh. The 50mm f/2 performs
>much like the excellent Tamron 90mm f/2.8 macro does for 35mm and APS
>digital. The zooms are remarkable performers - it is especially
>difficult to design a zoom lens which renders smooth out of focus
>highlights.
>
>All Carl Zeiss lenses for Contax 35mm SLRs and the G Series have
>excellent bokeh. Most Leica M lenses made before introduction of the
>latest ASPH series have superb bokeh. The ASPHs are merely good in
>that respect, but with truly outstanding sharpness - and distortion so
>low that it isn't worth even trying to measure it. But their bokeh
>has disappointed many Leica enthusiasts, to the point where used
>examples of the last pre-ASPH versions of some Leica lenses are
>selling at higher prices than the much newer ASPH versions.
>
>Going back to the 1970s and early 1980s, Kiron of Japan made some
>superb lenses that were sold under the Kiron and Vivitar brands. Alas
>these will not meter on the D70 because Nikon did not enable the use
>of pre-AF lenses. The can, however, be used on the D2Hs and D2X.
>

Bokeh is for armchair photographers.

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

John A. Stovall <johnastovall@earthlink.net> wrote:

>You forget Canon has some out standing boke lenses.


I didn't forget Canon. My experience with Canon is just too limited
for me to make sweeping overall judgements about the EF range. Canon
FD glass was renowned for good bokeh. I don't hear the same thing
being said about the EF range, but that doesn't mean there aren't some
good EF lenses.

I rent a Canon DSLR several times a year but only to use a rented 24mm
tilt and shift lens and my own Leica 28mm PC Super Angulon shift lens
for specific tasks. I briefly tried the EF 85mm f/1.8 (neutral bokeh)
and the 85mm f/1.2 (good but not excellent bokeh) a couple of years
ago but that's all.

Perhaps someone with better knowledge could express opinions on the
out of focus characteristics of the EF range.

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

"Frank ess" <frank@fshe2fs.com> wrote:

>Do I hear the sound of an enterprising programmer with artsy
>tendencies thinking, "Aha! _Genuine_ _Bokeh_! I'll be rich and
>famous!"


LOL!!!

One good thing about this thread is the fact that people are actually
discussing bokeh. Only a couple of years ago, certain people on
rec.photo.equipment.35mm were ridiculing the idea that bokeh even
existed. We have come a long way since then.

;-)

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

Tony Polson wrote:

>
> Perhaps someone with better knowledge could express opinions on the
> out of focus characteristics of the EF range.

Perhaps you should post from your vast photographic collection of photos
demonstrating the performance of these lenses.


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

Keep in mind that lenses with bad background bokeh often have good
foreground bokeh and vice-versa. You can't have both in one lens. That
would be a perfect lens that produced flatly illuminated disks (which is
considerd to be less-than-perfect bokeh. Good bokeh is, in itself, an
aberration, requiring uneven OOF disk illumination with the illumination of
the disk falling off at the edge. It's impossible to maintain this on both
sides of the focal plane. A dimmed edge on one side of the plane becomes a
bright edge on the other.

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

Bubbabob wrote:

> Keep in mind that lenses with bad background bokeh often have good
> foreground bokeh and vice-versa. You can't have both in one lens. That
> would be a perfect lens that produced flatly illuminated disks (which is
> considerd to be less-than-perfect bokeh. Good bokeh is, in itself, an
> aberration, requiring uneven OOF disk illumination with the illumination of
> the disk falling off at the edge. It's impossible to maintain this on both
> sides of the focal plane. A dimmed edge on one side of the plane becomes a
> bright edge on the other.

I've wondered about that. Foreground bokeh is rarely (very rarely)
discussed. I suppose that's natural as foreground objects are most
often excluded near the main subject, esp. if they have highlights that
would interfere with the image proper.

Any links or articles on the subject?

Cheers,
Alan.

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