Primes for Crop Bodies

Anouilh

I am thinking of getting a 35mm f2 EF Canon lens.

http://www.amazon.co.uk/Canon-35mm-Wide-Angle-Lens/dp/B00007EE8P

It will behave as a "normal" 50mm or so on a crop body (Canon eos 400d, Digital Rebel). If I should get a full frame digital it should continue to be useful.

If anybody has advice on performance and its use for street photography I would be really grateful.

I had thought about the Sigma f1.4 series, either 30mm or 50mm, but they are over 200 euro.

PaulieC

I had the Sigma 30mm f1.4 on a crop body (Canon 30D), which is roughly the same focal length as a nifty-fifty on full frame. I had not problems with it quality-wise, but I did notice that there was slightly more distortion than you would get with a 50mm on a full-frame. Because I got the lens for mostly portraits, I sold it as the distortion was of the non-flattering variety i.e. it made noses look bigger than they were :pac:

Looking at that link, though, I might picl on of those up...cheap as chips and very good quality...

CabanSail

Convention says that for Portraits you want a lens of about 130mm (equiv) so on a crop body an 85mm is about perfect.

That 35mm looks nice for a a general purpose prime.

Anouilh

Thank you both for such helpful information.

The 35mm f2 seems to be relatively elusive. It has several positive reviews on the net, but it's difficult to find anybody who actually owns one.

This is a good site for prime lens reviews:

http://www.prime-junta.net/pont/Reviews/da_Canon_35_mm_2/a_Canon_35_mm_f2.pdf

Apparently this is a very noisy lens, though I suppose everything is relative.

It might be a bit of a nuisance for street work, however.

PoleStar

Unless Im mistaken, a 30 or 35mm lens on a crop body will not be the same as a standard 50mm lens on full frame for the simple reason that perspective is different.

Thus a 35mm on a crop body will give the same perspective as on a full frame.

Im sure someone else can explain this better.

Anouilh

PoleStar wrote: »

Unless Im mistaken, a 30 or 35mm lens on a crop body will not be the same as a standard 50mm lens on full frame for the simple reason that perspective is different.

Thus a 35mm on a crop body will give the same perspective as on a full frame.

Im sure someone else can explain this better.

It's a question of field of view (fov). On a crop body, the scene will be narrower with the same lens. That is why one needs wide angle lenses for taking in groups of people with a crop body.

This is useful for anybody trying to decide on a prime for portraiture:

http://forums.macrumors.com/archive/index.php/t-690066.html

The next part of my project is to find time to try out different primes in a camera shop.

Anouilh

PoleStar wrote: »

Unless Im mistaken, a 30 or 35mm lens on a crop body will not be the same as a standard 50mm lens on full frame for the simple reason that perspective is different.

Thus a 35mm on a crop body will give the same perspective as on a full frame.

Im sure someone else can explain this better.

This seemsto explain all:

http://dpanswers.com/crop.html

There are many fans of the "nifty fifty" but I wonder if it would be a bit long on an eos crop body.

DonkeyStyle \o/

Anouilh wrote: »

There are many fans of the "nifty fifty" but I wonder if it would be a bit long on an eos crop body.

I find it too long sometimes yeah... for a nicely framed, landscape, head/shoulders shot, you're looking at being about 5 feet away (if memory serves)... which makes taking photos indoors a bit awkward by times... it's not terribly bad though... and for the price of a f1.8 50mm (~€100) there really isn't much to complain about.

PoleStar

Anouilh wrote: »

This seemsto explain all:

http://dpanswers.com/crop.html

There are many fans of the "nifty fifty" but I wonder if it would be a bit long on an eos crop body.

Thats exactly what I wanted to say!

Freddie59

I have the 50mm 1.4 and, like other posters point out, the lack of zoom, plus the crop body, can make things a little awkward. But it's some lens.:)

charybdis

PoleStar wrote: »

Unless Im mistaken, a 30 or 35mm lens on a crop body will not be the same as a standard 50mm lens on full frame for the simple reason that perspective is different.

Thus a 35mm on a crop body will give the same perspective as on a full frame.

Im sure someone else can explain this better.

Perspective is a function of distance, lenses have no direct effect on perspective.

For a fixed format size, lenses with longer focal lengths have a narrower angle-of-view that tends to require greater working distance for most subjects. It is this greater distance between focal plane and subject that renders perspective as "flat".

Similarly, lenses with shorter focal lengths have a wider angle-of-view that does not require such a large working distance for many subjects. It is the reduced distance between the focal plane and the subject that renders images with exaggerated perspective.

cambo_gueno wrote: »

I had the Sigma 30mm f1.4 on a crop body (Canon 30D), which is roughly the same focal length as a nifty-fifty on full frame. I had not problems with it quality-wise, but I did notice that there was slightly more distortion than you would get with a 50mm on a full-frame. Because I got the lens for mostly portraits, I sold it as the distortion was of the non-flattering variety i.e. it made noses look bigger than they were :pac:

Looking at that link, though, I might picl on of those up...cheap as chips and very good quality...

As you have said, a 30mm lens on a crop sensor body has a very similar angle-of-view to a 50mm lens on a full frame body; why do you think there was more "distortion" (assuming you are not taking about barrel distortion) compared to the 50mm?

Anouilh

A wide angle lens emphasises foreground objects, which can mean distorted features in portraits:

http://www.the-digital-picture.com/Reviews/Canon-EF-16-35mm-f-2.8-L-USM-Lens-Review.aspx

http://www.flickr.com/groups/nikkor50mm18/discuss/72157614337201782/

I'm going to have to try out different primes in a shop. Buying off the Internet with no prior experience could lead to years of scary photos of friends...

charybdis

Anouilh wrote: »

A wide angle lens emphasises foreground objects, which can mean distorted features in portraits

No it doesn't.

I just explained that it doesn't.

Anouilh

charybdis wrote: »

No it doesn't.

I just explained that it doesn't.

Many posters on the net seem to have a different experience.

I have no opinion, except to repeat hearsay.

I have seen photos of people taken on Flickr which are very unflattering due to distorted features. It's possible that they actually look like they are represented, but I doubt it...

Some of the more advanced lenses seem to balance optical distortion, which I suppose is barrel distortion.

I'm new to all this and shall study more...

charybdis

Anouilh wrote: »

Many posters on the net seem to have a different experience.

I have no opinion, except to repeat hearsay.

I have seen photos of people taken on Flickr which are very unflattering due to distorted features. It's possible that they actually look like they are represented, but I doubt it...

Some of the more advanced lenses seem to balance optical distortion, which I suppose is barrel distortion.

I'm new to all this and shall study more...

Others' experience is irrelevant, this is physics. If people are suggesting otherwise they are mistaken or imprecise.

Barrel distortion is another matter entirely.

Anouilh

charybdis wrote: »

Others' experience is irrelevant, this is physics. If people are suggesting otherwise they are mistaken or imprecise.

Barrel distortion is another matter entirely.

Quite...

Mr. Grieves

I think we're confusing definitions of distortion and perspective here.

Simply, if I stand close to someone, their nose will look bigger relative to the rest of their face than it would if I stould further back. Unless I'm mistaken, that's all there is to it.

Of course the reason you're standing further back may be because you have a longer lens, a smaller format or you're planning on cropping later etc etc, but the effect is the same.

sineadw

charybdis wrote: »

I just explained that it doesn't.

ah well then.. :rolleyes:

I think the point that Anouilh was making is that portrait shots (as in head shots) are not very flattering with a wide angle - they tend to 'emphasise'what's closest to them - usually the nose.

sineadw

Aaaaanyway...

@ Anouilh - Id be steering more towards the longer end of things for portrait shots. 50mm is not by any means long even on a crop body - quite the opposite. If you want it for street shots then go for it though. And at that money then why the hell not

Fionn

@Anouilh
if you go to this site it illustrates the subject pretty good - go to part three for a tutorial on lenses, perspective etc.

Anouilh

charybdis wrote: »

Others' experience is irrelevant, this is physics. If people are suggesting otherwise they are mistaken or imprecise.

Barrel distortion is another matter entirely.

Human perception has a lot to do with how science is used in everyday life. One of the professors in Maynooth College refused to enter the Aula Maxima because he claimed it defied all the laws of physics and was liable to collapse at any given moment...

There are some interesting ideas here:

http://forums.macrumors.com/archive/index.php/t-622892.html

Anouilh

This explains most of the questions raised so far:

http://www.bobatkins.com/photography/tutorials/portrait_lenses.html

cnocbui

I don't entirely agree with what is said on that page about perspective not being dependent on focal length.

In a portrait, there are usually two main elements. The first is the subject of the portrait and the second is the background behind the subject.

With a wide angle lens, you obviously have to stand fairly close to your subject to get the right proportions. The wide field of view means you often have less control of what will appear in the background of the shot because there will be more of it, thus a higher chance it will be 'busy', at least in the sense of taking photos in an uncontrolled setting.

With a short to moderate telephoto, you can often be far more selective about the background you include as a slight shift in shooting location can change it significantly since the field of view is narrower.

So the perspective in relation to the background is not independent of the focal length.

I personally like to use from 80mm to 180mm, on a 35mm camera, for portraits and lenses with at least f2.8, preferably f2. This allows even greater control of backgrounds as they can be blurred significantly.

If you want to shoot macro shots, an old school Tamron SP 90mm f2.8 macro is a fine instrument for the purpose, and low and behold, it is also an ideal focal length and aperture for portraits.

DaireQuinlan

I think there's a bit of confusion here. I don't think anyone is saying that the perspective doesn't depend on the focal length. This whole disagreement (or discussion :rolleyes:) is based on Cambo Gueno's assertion that the 35mm on his cropped body isn't equivalent to a 50mm on a FF body, because there's more distortion. Charybdis has pointed out that the two ARE equivalent (give or take a few mm), in which he is correct, and that CG's distortion is probably down to the effect of poor lens design or what have you (sigma prime). So yes, of course the perspective changes with the focal length all other things remaining equal, but on a cropped body the seemingly wider lens gives the same perspective as the 'normal' lens on a FF body.

Anouilh

DaireQuinlan wrote: »

I think there's a bit of confusion here.

Therein lies my inability to decide now on what to buy. I'm not in a hurry and have decided to try out my kit zoom at various focal lengths to see how I mostly like to take portraits. However, the discussion here emphasises how complicated things can get:

http://photography-on-the.net/forum/showthread.php?t=18664

I have some nice shots of full figures portraits taken at quite a distance with my 70-300 zoom. 88mm gives a pleasant balance, but really it's all a question of taste. I came across a reference to how Nan Goldin used a 35mm (on a full frame body) to create some very well regarded candid shots. Often I tend to associate "candid" with "weird" as every detail of a person's skin is recorded, which is sometimes not very flattering.

cnocbui

DaireQuinlan wrote: »

I think there's a bit of confusion here. I don't think anyone is saying that the perspective doesn't depend on the focal length.

I was referring to this statement from the page mentioned:

Now some people think that it's the focal length of the lens that governs perspective, but they'd be wrong. If you compare normal rectilinear lenses (i.e. not with fisheye lenses), the perspective is determined only by your distance from the subject.

And the distance from your subject is governed by the focal length, framing of the subject being equal. :rolleyes:

DaireQuinlan

I came across a reference to how Nan Goldin used a 35mm (on a full frame body) to create some very well regarded candid shots. Often I tend to associate "candid" with "weird" as every detail of a person's skin is recorded, which is sometimes not very flattering.

Wellll, candid just means casual or off the cuff, I think you're thinking of something different, maybe unflattering natural light or something as opposed to some flattering studio set up or something.

I've taken some great portraits with wide angles. They're great for jamming into people's faces and taking the shot. This was taken with a 50mm on a bronica which is about the equivalent of a 30mm on a 35mm framesize:




This was a 24mm (IIRC) on 35mm film