Popphoto rant

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

With a 1.6 "crop factor" a typical 70-200mm lens becomes a 112-320mm. Now
add your 2x teleconverter and you have 224-640mm lens. Now add the f stop
loss due to the teleconverter and the slower speed you'll be shooting at -
plus manual focus at the extreme end and camera shake is a real concern.

Bob S.


"Siddhartha Jain" <losttoy2000@yahoo.co.uk> wrote in message
news:1105985321.895560.108290@z14g2000cwz.googlegroups.com...
> Just started my Popular Photography subscription. The magazine's plain
> lousy. Its full of advertisments and the articles aren't worth
> anything. No indepth testing reports or insightful articles!! dpreview
> does a more thorough job anyday.
>
> Very disappointed!!
>
> Infact, one of the articles about teleconverters didn't look right to
> me. The "Editors" opine that on a dSLR (as compared to a film SLR) the
> teleconverter will magnify any shake or blur. I don't understand how
> can the affect of shake be more magnified on a dSLR than on a 35mm
> full-frame film camera? The 1.6x crop factor affects the angle of view
> and not the magnification. Right? So the affect of camera shake should
> be the same given that you blow up a sub-35mm dSLR and 35mm film shot
> in the same proportion. Right?
>
> - Siddhartha
>

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

Siddhartha Jain wrote:
> Just started my Popular Photography subscription. The magazine's plain
> lousy. Its full of advertisments and the articles aren't worth
> anything. No indepth testing reports or insightful articles!! dpreview
> does a more thorough job anyday.
>
> Very disappointed!!
>
> Infact, one of the articles about teleconverters didn't look right to
> me. The "Editors" opine that on a dSLR (as compared to a film SLR) the
> teleconverter will magnify any shake or blur. I don't understand how
> can the affect of shake be more magnified on a dSLR than on a 35mm
> full-frame film camera? The 1.6x crop factor affects the angle of view
> and not the magnification. Right? So the affect of camera shake should
> be the same given that you blow up a sub-35mm dSLR and 35mm film shot
> in the same proportion. Right?
>
> - Siddhartha

My logic with regard to the magnified shake question is like this:
There is a physical distance an image must be moved on the sensitive
plane in order for you to consider it blurred. The physical motion of
the camera necessary for sufficient image motion is smaller for smaller
sensors.

Right?


--
Frank ess

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

"Siddhartha Jain" <losttoy2000@yahoo.co.uk> wrote in message
news:1105985321.895560.108290@z14g2000cwz.googlegroups.com...
> Just started my Popular Photography subscription. The magazine's plain
> lousy. Its full of advertisments and the articles aren't worth
> anything. No indepth testing reports or insightful articles!! dpreview
> does a more thorough job anyday.
>
> Very disappointed!!
>
> Infact, one of the articles about teleconverters didn't look right to
> me. The "Editors" opine that on a dSLR (as compared to a film SLR) the
> teleconverter will magnify any shake or blur. I don't understand how
> can the affect of shake be more magnified on a dSLR than on a 35mm
> full-frame film camera? The 1.6x crop factor affects the angle of view
> and not the magnification. Right? So the affect of camera shake should
> be the same given that you blow up a sub-35mm dSLR and 35mm film shot
> in the same proportion. Right?
>
> - Siddhartha

did you not check out the mag before you subscribet to it? i got a 3 yr
subscription for 10.49 off ebay and am totally happy with it. keeps me
updated at least - and i think i have an own opinion to a point where i can
disagree with parts of the zine w/o freaking out.

sid

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

In message <whTGd.28935$Xs6.1044@twister.nyroc.rr.com>,
"BobS" <spam@eliminator.com> wrote:

>With a 1.6 "crop factor" a typical 70-200mm lens becomes a 112-320mm. Now
>add your 2x teleconverter and you have 224-640mm lens. Now add the f stop
>loss due to the teleconverter and the slower speed you'll be shooting at -
>plus manual focus at the extreme end and camera shake is a real concern.

Perhaps, but the increased need in relative shutter speed is not any
greater for a 1.6x crop camera than a full frame, when using the TC, so
the article makes an incorrect assertion, if the OP is paraphrasing it
correctly.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><

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

In message <bob_salomon-9F35C2.13351417012005@news.isp.giganews.com>,
Bob Salomon <bob_salomon@mindspring.com> wrote:

>Using the tele converter on the 70 to 200 with the 1.6x factor the lens
>is equal to a 224-640mm so the slowest hand held speed becomes 1/640th
>so yes the editors are right.

No; unless the editors said that the same lens with the same TC will
require a faster shutter speed with the 1.6x crop, which is not what the
OP implied. The OP implied that the editors said that putting a 2x
converter on a digital will require more of a shutter speed adjustment
than with full-frame film (less than half the exposure time).

It's one of those things that doesn't need to be said, and only is said
because someone was looking at it the wrong way.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><

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

In message <fNWGd.1647$Nu.781@fed1read04>,
"Mark²" <mjmorgan(lowest even number here)@cox..net> wrote:

><JPS@no.komm> wrote in message
>news:mvbou05gn0qg9t4q5aobh4n0jodvpkcuvg@4ax.com...
>> In message <whTGd.28935$Xs6.1044@twister.nyroc.rr.com>,
>> "BobS" <spam@eliminator.com> wrote:

>> >With a 1.6 "crop factor" a typical 70-200mm lens becomes a 112-320mm. Now
>> >add your 2x teleconverter and you have 224-640mm lens. Now add the f stop
>> >loss due to the teleconverter and the slower speed you'll be shooting
>> >at -
>> >plus manual focus at the extreme end and camera shake is a real concern.

>> Perhaps, but the increased need in relative shutter speed is not any
>> greater for a 1.6x crop camera than a full frame, when using the TC, so
>> the article makes an incorrect assertion, if the OP is paraphrasing it
>> correctly.

>It is different to the extent that eventual enlargement (prints) will be a
>greater ratio of enlargement compared with full-size sensor shots, and will
>therefore reveal more evidence of movement.

That is an obvious "given". What the paraphrase of the article implies
is that you have to compensate more when you take your lens off of a
DSLR with a crop factor, and stick a converter in-between, which is
nonsense. You double the denominator for a 2x TC, regardless of the
crop or lack thereof. It is a typical magazine profundity created by an
illusory starting point (you weren't using the proper shutter speed
before you attached the converter).
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><

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

Just remember your subscription will never run out either. I subscribed
for a year back in the 90s and am still getting the magazine.

--
http://www.chapelhillnoir.com
home of The Camera-ist's Manifesto
The Improved Links Pages are at
http://www.chapelhillnoir.com/links/mlinks00.html
A sample chapter from "Haight-Ashbury" is at
http://www.chapelhillnoir.com/writ/hait/hatitl.html

"Siddhartha Jain" <losttoy2000@yahoo.co.uk> wrote in message
news:1105985321.895560.108290@z14g2000cwz.googlegroups.com...
> Just started my Popular Photography subscription. The magazine's plain
> lousy. Its full of advertisments and the articles aren't worth
> anything. No indepth testing reports or insightful articles!! dpreview
> does a more thorough job anyday.
>
> Very disappointed!!
>
> Infact, one of the articles about teleconverters didn't look right to
> me. The "Editors" opine that on a dSLR (as compared to a film SLR) the
> teleconverter will magnify any shake or blur. I don't understand how
> can the affect of shake be more magnified on a dSLR than on a 35mm
> full-frame film camera? The 1.6x crop factor affects the angle of view
> and not the magnification. Right? So the affect of camera shake should
> be the same given that you blow up a sub-35mm dSLR and 35mm film shot
> in the same proportion. Right?
>
> - Siddhartha
>

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

In message <49_Gd.4527$Nu.616@fed1read04>,
"Mark²" <mjmorgan(lowest even number here)@cox..net> wrote:

>Obvious to you and I, perhaps, but not to folks who tend to ask these
>questions.

.... but let's get everything in a logical perspective.

If you're going to use a 1.6x-crop DSLR, then the denominator of the
longest shutter speed needs to be multiplied by 1.6x what it would be
for 35mm film. If you're going to use a 2x TC with either, you have to
double those numbers. The way the article stated (or was paraphrased),
it sounded like some special thing happens with digital and/or crops
that changes the basic principal. There is no need for such confusion.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><

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

<JPS@no.komm> wrote in message
news:0nsou09vgifv5mvo1rsjl492d4la7o8rgm@4ax.com...
> In message <49_Gd.4527$Nu.616@fed1read04>,
> "Mark²" <mjmorgan(lowest even number here)@cox..net> wrote:
>
> >Obvious to you and I, perhaps, but not to folks who tend to ask these
> >questions.
>
> ... but let's get everything in a logical perspective.
>
> If you're going to use a 1.6x-crop DSLR, then the denominator of the
> longest shutter speed needs to be multiplied by 1.6x what it would be
> for 35mm film. If you're going to use a 2x TC with either, you have to
> double those numbers. The way the article stated (or was paraphrased),
> it sounded like some special thing happens with digital and/or crops
> that changes the basic principal. There is no need for such confusion.

Yes. I see what you're focussing on there. I was talking more to the basic
question of whether camera shake can be more evident a problem when using a
smaller sensor vs. film. The apparent point about the 2x TC is indeed
silly...if that's what they were saying.

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

Phil Wheeler wrote:
> Substitute the name of most photo mags and the above would still
apply.
> I'm surprised that someone who knows about dpreview would subscribe
to
> Pop Photo. Didn't you buy a test issue at the newstand first??

In India, one issue of Popphoto sells for $4 in premier book shops!! So
I thought, what the heck, let me order a year's subscription for $20. I
think I will stick to learning the googling way from now on. And
ofcourse, a few decent sites like dpreview, luminous-landscape and
megapixel.net.

- Siddhartha