35mm verses 50mm for 7D

[gene_can_sing]

If you guys had to choose between a 35mm or a 50mm as a general purpose / low light lens for the 7D, which focal length would you go with?

I'm thinking about getting the $90 50mm EF 1.8 or spending an extra $100 for the Nikon 35mm f/1.8G AF-S DX (would this lens even work on the 7D with an adapter)?

If you guys had to choose between these 2 lenses (considering the different focal length), which one would you go with?

Thanks so much for all your help.

[ydgmdlu]

You can't use the Nikon because, as a G series lens, it doesn't have a built-in aperture control ring. So you won't be able to set the aperture at all when using the lens on a Canon camera, unless you buy this pricey adapter: http://www.16-9.net/nikon_g/

50mm won't be wide enough for "general purpose." I suggest the Sigma 30mm f/1.4. The lens has plenty of prominent fans here; there's a thread all about it: http://www.dvxuser.com/V6/showthread.php?t=184163

[mhood]

You might also consider the Canon EF 28mm 1.8 USM.

[dcloud]

yep sigma 30 1.4 is great.
if you like super dof, this one doesnt have it unless your pretty close. besides i dont like too much DOF blur

[Jean Dantes]

yep sigma 30 1.4 is great.
if you like super dof, this one doesnt have it unless your pretty close. besides i dont like too much DOF blur


Doesn't the DOF have to do with aperture setting?

And what do you mean by "pretty close"?

[Kholi]

Doesn't the DOF have to do with aperture setting?

And what do you mean by "pretty close"?

DOF does have to do with Aperture setting. Perceived "shallowness" also has to do with relationship in distance between lens, foreground, subject/focal plane and background.

The Sigma wide series (20, 24, 28, 30) are mostly Macros so you can "Close Focus" down to near-inches which will throw your "background" out of focus a lot more.

What DCloud is misunderstanding is that a lens will have the same amount of shallow focus no matter which distance the subject is from the camera, which means the lens is just as shallow at all times. It's simply what you're shooting and how you're shooting it that makes it appear less or more.

A lens that has a very small close focus distance is ideal, this is mostly what I'd like to have the Sigma's for but still have yet to shell out for them.

To the OP: the 30/1.4 is a great option for a cheap lens and the resale value is nice. If, however, you're looking to get a 35/1.8 versus a 50/1.4, my vote will always by the 35mm. This will probably be your go to lens for most shots if you're composing traditionally.

[ydgmdlu]

What DCloud is misunderstanding is that a lens will have the same amount of shallow focus no matter which distance the subject is from the camera, which means the lens is just as shallow at all times. It's simply what you're shooting and how you're shooting it that makes it appear less or more.
No, it's not just a matter of "perceived shallowness." Subject to focal plane distance is part of the mathematical DOF formula: http://en.wikipedia.org/wiki/Depth_of_field#Derivation_of_the_DOF_formulas


To the OP: the 30/1.4 is a great option for a cheap lens and the resale value is nice. If, however, you're looking to get a 35/1.8 versus a 50/1.4, my vote will always by the 35mm. This will probably be your go to lens for most shots if you're composing traditionally.
Just don't get the Nikon G series lens.

[Kholi]

No, it's not just a matter of "perceived shallowness." Subject to focal plane distance is part of the mathematical DOF formula: http://en.wikipedia.org/wiki/Depth_of_field#Derivation_of_the_DOF_formulas


Perceived is an easy way of explaining how Hyperfocal distance impacts "depth of field". But, you can surely read that Wiki for a few hours and if you come out with the ability to do the math on set in your head, you're a wizard.




Just don't get the Nikon G series lens.

Why not? Because it doesn't have an aperture ring? Just use paper, q-tip or get an adapter that controls the aperture manually.

[ydgmdlu]

Why not? Because it doesn't have an aperture ring? Just use paper, q-tip or get an adapter that controls the aperture manually.
I forgot that you're partial to such workarounds. :)

[Kholi]

I forgot that you're partial to such workarounds. :)

LOL. Yeah, I will admit that it sounds like a risky feat but for the most part, not much that will hold the aperture open can get jammed in there. I WOULD recommend getting an actual adapter that you can control aperture with.

Actually, just don't even listen to me. I thought about putting a Q-Tip in a twenty-two hundred dollar ($2,200.00) lens and it dawned on me how bad that sounds.

[ydgmdlu]

LOL. Yeah, I will admit that it sounds like a risky feat but for the most part, not much that will hold the aperture open can get jammed in there. I WOULD recommend getting an actual adapter that you can control aperture with.
I agree that that would be the best solution, but the OP sounds like his budget is tight and most likely can't afford such an adapter (which I linked in my original reply) as an added expense on top of the price premium of the 35mm f/1.8 over the 50mm.

[Kholi]

I agree that that would be the best solution, but the OP sounds like his budget is tight and most likely can't afford such an adapter (which I linked in my original reply) as an added expense on top of the price premium of the 35mm f/1.8 over the 50mm.

True indeed. 30/1.4 Sigma it may very well be. I need to finally pick that lens up to toy with!

[ydgmdlu]

And, of course, let us know how you like it. :)

[visugeek]

Doesn't the DOF have to do with aperture setting?

And what do you mean by "pretty close"?

Here is a chart and a calculator that you can use to get an idea. Plug in the focal length and camera type, in this case, I think the Canon Rebel XT, or scroll down to Cinematography and choose 35mm as the sensor in the 7D is between Academy and Super 35mm in size. They don't have the 7D as a choice yet.

DOF changes with the sensor size, focal length, and aperture. Plug in some different numbers and you'll get an idea of the relationship. Wider focal lengths mean more of the image is in focus, no matter what the stop. The smaller the sensor, the same thing. That is why a camcorder with a small sensor and a wide lens will have EVERYTHING in focus.

The reason why camera assistants measure on a set is to guarantee that they keep the talent within that acceptable range. If the DOF is really shallow, it's best to measure to the eyes.

http://www.dofmaster.com/doftable.html

http://www.dofmaster.com/dofjs.html

[Elephantalk]

You guys aren't fond of canon 35mm f2 I guess since nobody mentioned it? I myself are on the same boat as I prefer 35mm fov on aspc over 50mm.