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10-27-2010, 02:14 AM   #16
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Recently, this came out on this thread as well.

10-27-2010, 04:45 AM   #17
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QuoteOriginally posted by RioRico Quote
Constantly translating crap factors will drive you nuts. Just get out there and SHOOT!
QuoteOriginally posted by Col Quote
CRAP factor! I think your true feelings are showing through Though I'm in total agreement with you...
This is one of the good examples of Freudian "slip of the tongue" cases in Psychology, it most probably indicates a very strong unconscious and repressed wish and conflict, through FF sensors or larger.

Freudian slip - Wikipedia, the free encyclopedia
10-27-2010, 11:31 AM   #18
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QuoteOriginally posted by icypepsi Quote
Here's what I don't understand. I was looking at the Tamron 70-200mm 2.8 at B&H the other day paired with my K7. At 70mm it had the exact same FoV of what my 18-200mm looked when it is at 70mm...
Yep, both lenses are set to 70mm, so you'll get the same field-of-view.
10-27-2010, 11:34 AM   #19
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QuoteOriginally posted by Raylon Quote
All lenses are measured to 35mm film standards, not FF or APS-C. .
Nope. All lenses are marked according to the ACTUAL physical focal length of the lens, not according to "35mm film standards".

10-27-2010, 11:37 AM   #20
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QuoteOriginally posted by egordon99 Quote
Nope. All lenses are marked according to the ACTUAL physical focal length of the lens, not according to "35mm film standards".
Aren't both the same?
10-27-2010, 01:04 PM   #21
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QuoteOriginally posted by Squier Quote
I still see thousands upon thousands of photographic websites, even reviewers, and many many ordinary amateurs repeat this stuff ad infinitum, parrot fashion, claiming they get extra reach when simply mounting a lens on a crop camera. Its become a legend that wont go away

The only way to get extra reach is with a Teleconverter, assuming we match like for like / pixel density between cameras
But that matching of the pixel densities is what you always have to account for.

For example, you're going to get more effective 'reach' from shooting a 300mm lens on a 12MP aps-c D300 than a 12MP FF D3, because if you crop that 12MP D3 FF shot, you're left with about 5MP. Good enough for a lot of applications, but you start to notice that resolution drop when print bigger. Also, you can't crop much more than that and keep the image viable.

Even a 21MP FF crops down to 10MP or so when trying to reach aps-c FOV.

This is the reason a lot of wildlife & sports pros shoot APS-C bodies for good-light telephoto.



.

Last edited by jsherman999; 10-27-2010 at 01:10 PM.
10-27-2010, 01:13 PM   #22
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I agree with you, but with regard to the myth of the ' magical ' focal length increase, we dont see this pixel density mentioned.

What we see is " stick this 500mm lens on your 1.5x crop camera and get 750mm reach "

This is what i'm addressing as a general myth buster
10-27-2010, 01:35 PM   #23
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QuoteOriginally posted by Squier Quote
I agree with you, but with regard to the myth of the ' magical ' focal length increase, we dont see this pixel density mentioned.

What we see is " stick this 500mm lens on your 1.5x crop camera and get 750mm reach "

This is what i'm addressing as a general myth buster
Another myth I see almost as often is: "just crop out the central part of the FF shot and it's exactly the same as the APS-C shot! No reason to shoot APS-C, just crop FF!"

To the larger question of FOV folks have been discussing in this thread - if you shoot film & aps-c or FF and aps-c, you do have to keep the FL conversion factor in your head. It's not enough to say "a 50mm lens is a 50mm lens, period!" because you completely change the FOV when you swap that lens between bodies, and you can't keep the MP in the image circle the same simply by cropping.

This seems like a 'duh' concept, but it kinda makes the "a 50mm lens is a 50mm lens" one of those statements that's technically correct, but has little bearing in real world applications (unless you only ever shoot one format, then it does, and the crop factor discussions become annoying. )


.

10-27-2010, 01:52 PM   #24
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QuoteOriginally posted by jsherman999 Quote
Another myth I see almost as often is: "just crop out the central part of the FF shot and it's exactly the same as the APS-C shot! No reason to shoot APS-C, just crop FF!"

To the larger question of FOV folks have been discussing in this thread - if you shoot film & aps-c or FF and aps-c, you do have to keep the FL conversion factor in your head. It's not enough to say "a 50mm lens is a 50mm lens, period!" because you completely change the FOV when you swap that lens between bodies, and you can't keep the MP in the image circle the same simply by cropping.

This seems like a 'duh' concept, but it kinda makes the "a 50mm lens is a 50mm lens" one of those statements that's technically correct, but has little bearing in real world applications (unless you only ever shoot one format, then it does, and the crop factor discussions become annoying. )


.
the fact is that no one really compares pixels in the image circle when considering using a lens on FF or ASP-C, regardless of what I am shooting between film (the old analog equivelent of FF) and digital ASP-C I pick a lens that gives me the field of view first and foremost, then set the lens for the DOF I want, and shoot. I don't give a damm about whether the image is anywhere between 6MP and 14MP (ranging between my *istD and K7. My film scanner is 2880 dpi which is 10MP like my K10) what I want is an image that when printed at 11x 17 is acceptable to me, and a full 6MP image printed on 11 x 17 is just fine for resolution.

the whole point is, that field of view has been a discussion since the film days, and one of the early books I have on photography shows a table of FOV as a function of format for lenses covering 35mm film, 6 x 6 cm format, 6 x 7 cm fomat(120 roll film) and 4 x 5 inch, (speed graphic)

there was no "crop factor" or magnification ratio or anything else discussed. it was just FOV vs format. so why are we now magically so thick we can't accept comparing FOV as a function of just one more format?

I think the following quote really applies here.

the intelligence of the world is a constant... The population is growing
10-27-2010, 01:54 PM   #25
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yeas, some good points again
10-27-2010, 02:18 PM   #26
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QuoteOriginally posted by Lowell Goudge Quote
...there was no "crop factor" or magnification ratio or anything else discussed. it was just FOV vs format. so why are we now magically so thick we can't accept comparing FOV as a function of just one more format?
.

Because, like it or not, pixel density and sensor resolution play a large role in things now, in people's choices, and that's pretty much tied directly to cost.

I want a certain FOV; I can shoot a 450mm f/5.6 lens on FF, or a 300mm f/4 lens on APS-C. They both will give me roughly the same image (using the same pixel density,) but the FF solution will cost probably 3 times as much.

So, I could just use the 300mm lens on the FF body and crop the image to save lots of money, but then I'm down to 5MP. Big enough to print at 11x16? Maybe. Some would say, not. And what if I want to print larger, or sell the image to someone who might, or crop the image further? Would a TC be better? (surprisingly, in many cases, no.)

And if I'm cropping most of my FF telephoto images, would it make sense to pick up a used APS-C body for my telephoto needs, and get all those pixels inside the image circle? By George, it might!

But what if I put that APS-C money towards a higher-resolution FF body? Will 10MP in the image circle be enough after a crop?

(and the discussion continues, with opinions mixing with biases mixing with myths... )


.
10-27-2010, 03:06 PM   #27
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I get it!

Makes perfect sense, Raylon. Clearly, I had the wrong notion that APS-C lenses were marked differently and that way the magnification itself is different at a given FL.

I'm sure people meant the correct facts when they wrote on forums. But, I think the legends of changes in FL on/for different sensor areas began to take shape when learners make their own numerical deductions from English (or other) sentences.

Perfect idea, RioRico. I think I just have to look at what FL I'm actually interested in and go from there. I eventually wanted to get myself a sharper, low-light friendly lens. People making the standards were actually trying to make it easy for me to make my choices

Thanks everybody! Cheers...
10-27-2010, 03:19 PM   #28
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For better and better

QuoteOriginally posted by jsherman999 Quote
.

Because, like it or not, pixel density and sensor resolution play a large role in things now, in people's choices, and that's pretty much tied directly to cost.
...

.
True. There are so many other things people will also consider. From weight/size to features to even just the good-feel of having an FF. I personally thought the FF sensor itself had a lot better low light noise performance (partly because of the pixel size). Now I see the K5 and I'm thinking that eventually technology gives that which are missing. Ofcourse, the FF gets better also, but then there are other factors you are looking at too. Features, speed, or even if you can wait for technology to come out.
10-27-2010, 03:27 PM   #29
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You can forgive the likes of us end users being taken in by BS, but i cant forgive the marketeers for cold bloodedly perpuating the FL magic increase BS, simply because its a sales increase, and they all know it.

There is no magic, and thats all there is to worry about. If you comtinually swap your lenses onto FF and Crop and back again, the FOV can be amazing / disappointing, but mostly there's nothing to worry about.

Stick a 500 mm lens on your Crop bod and get a 500 mm focal length
10-27-2010, 03:52 PM   #30
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Seriously! It is so easy to fool an end user (not just talking photography).

But knowing the truth about those markings actually makes me feel greater about my already esteemed K7. (Cant beat it for per-camera-per-money! Except with the K5 I guess )
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