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Jredtugboat
05-03-2005, 02:37 PM
Hi gang,

I'm just wondering about something. In reading various articles on portraiture, I've heard it said that many photographers are using lenses with focal lengths in the ~100mm range.

Is there any particular reason for this? Or is it just coincidence?

I'm curious about this. I'm considering a EOS-20d, is there some lens in this class that makes a lot of sense for portraits--maybe more than others?

Usage note: I'm not at all equipped for studio photography. Not yet. I'm trying to exercise some spending discipline here...

yours,

Julian

Rhys
05-03-2005, 02:51 PM
Hi gang,

I'm just wondering about something. In reading various articles on portraiture, I've heard it said that many photographers are using lenses with focal lengths in the ~100mm range.

Is there any particular reason for this? Or is it just coincidence?

I'm curious about this. I'm considering a EOS-20d, is there some lens in this class that makes a lot of sense for portraits--maybe more than others?

Usage note: I'm not at all equipped for studio photography. Not yet. I'm trying to exercise some spending discipline here...

yours,

Julian

I've always heard arguments by most professionals and most camera-makers that the 85mm lens is the perfect portrait lens. Hence many manufacturers make a very fast 85mm lens. The other common length is 105mm.

jamison55
05-03-2005, 03:06 PM
Hi gang,

I'm just wondering about something. In reading various articles on portraiture, I've heard it said that many photographers are using lenses with focal lengths in the ~100mm range.

Is there any particular reason for this? Or is it just coincidence?

I'm curious about this. I'm considering a EOS-20d, is there some lens in this class that makes a lot of sense for portraits--maybe more than others?

Usage note: I'm not at all equipped for studio photography. Not yet. I'm trying to exercise some spending discipline here...

yours,

Julian

It has to do with distortion. Lenses wider than 50mm give the subject the appearance that he/she is wider than real life. 50mm lenses are said to give an accurate representation of the subject. Lenses longer than 50mm give the subject the appearance that he/she is narrower than real life. How do you think most people like to appear...? ;)

Keep in mind that the same effects appear on primes that are mounted on 1.5/1.6 CF cameras. That 35mm will have the same distortion that it does on a full frame camera, even though it is cropped to a 55mm FOV on your DSLR!

Herein likes the problem. If you have a small studio, like me, you are forced to use wider WA lenses on your DSLR to ensure that your entire subject is in the photo...

For large studios or outdoor work, the perfect Canon portrait lens is the 85 f1.8. Just shot my first portraits with mine, and it is magical! http://fphoto.org/jamiewexler/FL%20Family%20Portraits/afl05%20240

For comparison, here's another shot with the Canon 85 1.8: http://fphoto.org/jamiewexler/FL%20Family%20Portraits//afl05%20225

And one with my (excellent) Tamron 28-75 f2.8 at 28mm: http://fphoto.org/jamiewexler/FL%20Family%20Portraits//afl05%20272

Yes, that's me in the orange shirt, surrounded by my family, with the tripod doing all of the work...but ignore that for now. Take a look at the couple that appears in both of the photos. In which picture do they look thinner?

jeisner
05-03-2005, 03:56 PM
It has to do with distortion. Lenses wider than 50mm give the subject the appearance that he/she is wider than real life. 50mm lenses are said to give an accurate representation of the subject. Lenses longer than 50mm give the subject the appearance that he/she is narrower than real life. How do you think most people like to appear...? ;)

Keep in mind that the same effects appear on primes that are mounted on 1.5/1.6 CG cameras. That 35mm will have the same distortion that it does on a full frame camera, even though it is cropped to a 55mm FOV on your DSLR!

Herein likes the problem. If you have a small studio, like me, you are forced to use wider WA lenses on your DSLR to ensure that your entire subject is in the photo...

For large studios or outdoor work, the perfect Canon portrait lens is the 85 f1.8. Just shot my first portraits with mine, and it is magical! http://fphoto.org/jamiewexler/FL%20Family%20Portraits/afl05%20240

For comparison, here's another shot with the Canon 85 1.8: http://fphoto.org/jamiewexler/FL%20Family%20Portraits//afl05%20225

And one with my (excellent) Tamron 28-75 f2.8 at 28mm: http://fphoto.org/jamiewexler/FL%20Family%20Portraits//afl05%20272

Yes, that's me in the orange shirt, surrounded by my family, with the tripod doing all of the work...but ignore that for now. Take a look at the couple that appears in both of the photos. In which picture do they look thinner?


This is correct from what I know, also I think 85-100 gives a comfortable working distance as you don't want to be in someones face ;)

TheObiJuan
05-03-2005, 04:28 PM
The 135 on a full frame is akin to the 85 on a 20D. The 50mm is closer to the 85 on a 20D too. The only downside is the compression and perspective remains the same while the field of view changes. I will get the 85 to compliment my 135 and 50. The 85 will be my head and shoulder's lens, I will just move the tripod bag to adjust for the 1.6 crop.

Jredtugboat
05-03-2005, 06:58 PM
It has to do with distortion. Lenses wider than 50mm give the subject the appearance that he/she is wider than real life. 50mm lenses are said to give an accurate representation of the subject. Lenses longer than 50mm give the subject the appearance that he/she is narrower than real life. How do you think most people like to appear...? ;)

Keep in mind that the same effects appear on primes that are mounted on 1.5/1.6 CF cameras. That 35mm will have the same distortion that it does on a full frame camera, even though it is cropped to a 55mm FOV on your DSLR!

Herein likes the problem. If you have a small studio, like me, you are forced to use wider WA lenses on your DSLR to ensure that your entire subject is in the photo...

For large studios or outdoor work, the perfect Canon portrait lens is the 85 f1.8. Just shot my first portraits with mine, and it is magical!
<snip>

Hi,

This is great...to be sure that I'm reading you properly...

For the equivalent 85mm effect, I'd have to take into accoun the -20d's 1.6x crop factor? Is this just a case of multiplying any given focal length on on the lens (prime or not) by 1.6? Ex., my 50mm f/1.8 would really be 80mm, with the accompanying 'slimming' effects of an 80mm lens.

A 35mm lens will make people look fatter, uh, wider. True? And (again, to make sure I'm reading you correctly) it will still make them look wider on my -20d even as the 35mm lens has "become" a 56mm?

I'm pretty new to this. In fact, I've never bought a lens before in my life!

Thanks,

yours,

Julian

Rex914
05-03-2005, 07:03 PM
It's actually multiplying the focal length by 1.6x. Think about it and why they call it the "crop factor."

Think about what happens to a picture when you zoom in (increase focal length). Besides the increase in detail capture and all that good stuff, you've also decreased your field of view (also called angle of view) and "cropped" out the rest of the picture. Think of the crop factor in that sense...

So in effect, you haven't increased the focal length at all. It's this crop that gives the illusion that that's happened.

Jredtugboat
05-03-2005, 07:07 PM
It's actuall multiplying the focal length by 1.6x. Think about it and why they call it the "crop factor."

Think about what happens to a picture when you zoom in (increase focal length). Besides the increase in detail capture and all that good stuff, you've also decreased your field of view and "cropped" out the rest of the picture. Think of the crop factor in that sense...

O.k., see, I've never thought about the FOV issue before--which is odd, because I'm always conscious of it when I use other optics, like binoculars. (We have three pairs aboard the boat I work on, and I always opt for the widest FOV model, because it allows me to judge distances and relative closing rates better.)

Yeah, multiplying...not dividing...I edited that last post to fix that. Thanks!

yours,

Julian

jamison55
05-03-2005, 08:09 PM
For the equivalent 85mm effect, I'd have to take into accoun the -20d's 1.6x crop factor? Is this just a case of multiplying any given focal length on on the lens (prime or not) by 1.6? Ex., my 50mm f/1.8 would really be 80mm, with the accompanying 'slimming' effects of an 80mm lens.

If only this were true...no the 50mm will have all of the optical "true to life" qualities of a 50mm whether it is on a film SLR or a 1.6CF digital. Even though the FOV is cropped to be the equivalent of an 80mm, it still retains the optical effect of a 50mm, so no slimming. To get the slimming you would have to purchase the 85mm, which becomes a 135mm with the FOV crop on the 20D (but with the slimming effect of an 85 - not the additional slimming of the 135).


A 35mm lens will make people look fatter, uh, wider. True? And (again, to make sure I'm reading you correctly) it will still make them look wider on my -20d even as the 35mm lens has "become" a 56mm?


Now you are getting it. Lenses have the same distortion effect whether on full frame or cropped sensor cameras. See why everyone wants affordable full frame cameras?

Jredtugboat
05-03-2005, 09:51 PM
If only this were true...no the 50mm will have all of the optical "true to life" qualities of a 50mm whether it is on a film SLR or a 1.6CF digital. Even though the FOV is cropped to be the equivalent of an 80mm, it still retains the optical effect of a 50mm, so no slimming. To get the slimming you would have to purchase the 85mm, which becomes a 135mm with the FOV crop on the 20D (but with the slimming effect of an 85 - not the additional slimming of the 135).



Now you are getting it. Lenses have the same distortion effect whether on full frame or cropped sensor cameras. See why everyone wants affordable full frame cameras?

Ah, ok. I will have to run this through a few times in my head, but I think I get it now.

And yes. I want an affordable full-frame camera! With prices still in the $8,000 mark, kind of makes you wonder when that's going to change? We can all dream, can't we...

yours,

Julian

cwphoto
05-10-2005, 12:16 AM
A change in focal length will have an effect on Perspective Distortion (PD). A longer focal length will decrease PD, but won't make your subject appear thinner - certainly not in the X & Y planes.