Which of these lenses to choose for a studio project?

Question

I'm preparing for my first professional studio photography project and am seeking advice on the best lens to use for portraits, including full-body shots and headshots. I have a Canon EOS RP with an EF adapter and the following lenses:

• Canon 50mm f1.4
• Canon 85mm f1.8
• Canon 70-200 f4 L series (an older model without IS)

In my home or DIY studio setups, I've typically used the 50mm f1.4 due to space constraints. However, in the professional studio, space won't be an issue. My goal is to achieve the sharpest and most detailed images possible, likely shooting between f7.1 and f9.

I understand that prime lenses often offer better sharpness and detail, especially in studio settings. However, my 50mm and 85mm are not L series lenses, whereas my 70-200mm is, albeit an older model.

Given these factors, would the non-L series prime lenses (50mm or 85mm) be more suitable for studio work than the L series 70-200mm f4, considering my focus on sharpness and detail?

Answer 1

There's really never an objective "best" choice, it all depends on what you're attempting to accomplish.

My goal is to achieve the sharpest and most detailed images possible, likely shooting between f7.1 and f9.

Just my personal take, but all three of those lenses are pretty sharp at those apertures:

• EF 50/1.4 USM vs. EF 85/1.8 USM at f/8 on full frame.
• EF 70-200 f/4L USM vs. EF 85/1.8 USM at f/8 and 85mm on full frame

f/8 is the great equalizer among lenses. :D The 85/1.8 might win by a hair over the other two but probably not enough to make much practical difference.

But you may be aiming for the wrong goal here. Sharpness in portrait photography can be a double-edged sword. Delineating every nose hair, pore, and wrinkle as sharply as possible may not be that flattering (it's why I don't use a macro lens for portraits). You may actually want some thin DoF to help "pop" a subject. And maybe something more in the mid-range of apertures, like f/4 or f/5.6 might still give you enough DoF to cover your subject, but slightly blur a background vs. f/9. And, more importantly, won't be requiring as much power/light output from your strobes. Which can help speed up your recycle times.

You also want to consider working distance and perspective distortion. None of these lenses are likely to be exhibiting much lens distortion, but short lenses, used closer in, tend to exhibit perspective distortion if you try to maintain the same framing, particularly with headshots.

There are reasons some full frame shooters like a 135mm (which, btw, is the center of the 70-200 range), not just an 85mm, for headshots. :) But not everybody wants to deal with the working distance of a longer lens when it comes to connecting with and directing a subject.

Which lens will work the best for you depends on both you and your subject. How close do you need to be to effectively communicate? How are you planning on framing (head, torso, full length?). What apertures and depth of field do you want to use? How much, if any, background blurring do you want? And how much power/spread do you have with your lights and modifiers?

Also, since this is a studio situation, there's no penalty in having all three lenses available to you to choose at will. And you should also give yourself enough time with each lens to know how they'll behave in the space before you ever put a paying client in front of them.

Answer 2

If you want the sharpest images:

• turn off image stabilization
• use an f/stop one down from the largest aperture
• put the camera on a tripod
• use flash instead of constant light
• use the fastest flash sync speed your camera/strobe setup allows
• use enough power to set the ISO to the lowest setting possible
• prime lenses are usually sharper than zoom lenses

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Do test shots using all the lenses at the distances you plan to shoot. Your depth of field should cover from the tip of the nose to the back of the ear with some space for the subject to move a bit. Focus on the near eye. Though one stop smaller than maximum usually yields the sharpest images, you may have to use a smaller aperture than that to get the DOF large enough to cover your subject.

As @inkista said above, The slight telephotos look better optically, than the shorter lenses so leave the 50mm in your bag.

Shoot RAW. You can always soften a too sharp image in post production. It's much harder to sharpen a soft image.

If you're renting a studio, don't forget - unless you're in a smaller photo market - that you can rent lenses.

What is the reason images have to be super sharp? What is the final use of the iamges going to be? Print? Web? Posters? Billboards?