Is 85mm really ideal for portraits?

[JBPhotog]

@adamhiram another consideration for you to think about is aspect ratio. You always hear "fill the frame" but what do you do when you've "filled the frame" on a sensor with its 3:2 aspect ratio, and Mom wants an 8x10 (5:4) or an 11x14 (14:11) Your beautiful image is going to be missing something, or you spend some quality time in PS adding length/width, so you can crop to the correct ratio. A better option for me is a little pre-planning (choice of focal length and required FOV) for the anticipated final image so I have room to crop.

There is an easy fix for shooting in 5:4 aspect ratio if the plan is making typically sized prints. Set your Image Area in the Shooting Menu and choose 5:4, crop marks will be visible and your image captured will be cropped to that aspect ratio. Its always a good practise to leave a bit of breathing room around your subject unless of course you are in tight.

 

[adamhiram]

Thank you all for the great feedback.

• I've been happy with my Nikon 85mm f/1.8 since I got it a few years ago, and I'm leaning towards replacing it with the Z-mount version, which is significantly sharper, less prone to flare, and does much better with chromatic aberration.
• 105mm seems like a good compromise between longer focal length and comfortable working distance - I've had some challenges using an 85mm on a crop sensor in tighter spaces, which is roughly equivalent to 135mm on full frame. However the high price of the Nikon lens and the absurdly large size of Sigma's offering probably make this a no-go.
• 135mm seems like a a good 2nd option to have if I hold onto my 85mm. The lens size (at least for the Sigma) is more reasonable, and I'm pretty used to that working distance.

Thanks again, and I'll try to follow up if I make any decisions in the future. From everyone's experiences, it sounds like there's really no wrong answer.

 

[mrca]

The lens length does not effect compression, camera subject does. A 35 mm lens will have the same compression as an 85 at 7 feet. You can just crop. Want to see this without a lens, stand at the bathroom sink against the counter. Look at your nose, take a step back and watch it look smaller. Take another step back, smaller again, another the same. What is ideal is what is your vision of compression and what you feel is proper for a particular face. Only you know your vision. With my ample italian probiscus, I want you back 10-12 feet. At 15 feet I have a michael jackson nose. Chose the compression from the distance you like then chose the lens for the angle of view you desire. This is the same for any other photography but has been forgotten with so many folks using zooms and just standing in the spot they first see the shot, zooming and shooting. Setting perspective should be done before lens selection if possible. My choice for a head and shoulders 8-10 feet distance and a 100 or 135. There is compression but not excessive for my taste. I trained with 2 photographers who charge 45 grand for a wedding. They used the 85 for 3/4 couple shots during the day. I listen to folks that get paid that kind of money.

 

[AlanKlein]

The lens length does not effect compression, camera subject does. A 35 mm lens will have the same compression as an 85 at 7 feet. ... I trained with 2 photographers who charge 45 grand for a wedding. They used the 85 for 3/4 couple shots during the day. I listen to folks that get paid that kind of money.

What did they use for a head and shoulder shot of one person?

 

[Pixeldawg1]

The focal length makes no difference to the distortion -

Sorry, but this is quite incorrect. To prove it, shoot the subject with them at the same size on-camera at 24mm and then again at 105mm. Huge difference due to the focal length.

 

[petrochemist]

Your not understanding what I am talking about.

Registration distance is the distance from the focal point to the image plain for those not knowing.

Your definition of registration is different from that I've met all over the place in the past, both on-line & in print, and doesn't describe a constant distance let alone a feature of the lens. Registration is usually used to mean the same as back focal length, the distance of the image plane from the mounting flange of the lens.

The minimum distance of the image plane from the focal point (ie along the lens axis) is dependant on the distance being focused and the lenses focal length. When focused at infinity the image plane passes throught the focal point (by definition), When the image size is the same as the subject size (1:1 macro) the image plane is one focal length behind the focal point, by the time the subject is at the front focal point the image distance is at infinity.

 

[petrochemist]

The focal length makes no difference to the distortion -

Sorry, but this is quite incorrect. To prove it, shoot the subject with them at the same size on-camera at 24mm and then again at 105mm. Huge difference due to the focal length.

Only as you move to reframe the subject to the same size. It's the movement that makes the difference.

Leave the camera behind & compare the look of something close up to the same subject at a distance & you'll see close up distorts the perspective due to the relative distances being so different.
Stand ~10' from someone & their nose & ears are both ~10' away (close enough not to be noticeable) then stand 1' from someone & the roughly 6" distance from nose to ears beomces significant, the ears being 1.5x further from the lens look smaller.

 

[petrochemist]

The distance from the focal point to the image plane is known as (indeed, defined as) as the 'focal length'.

No, - it's image plane (at infinity) to the lens. The focal point is where the lens axis meets the image plane when focused at infinity or perhaps more accurately the point where a light source on the lens axis at infinite distance is brought to focus (which means the same thing).
With simple thin lenses this defintion was easy, but with most photographic lenses we don't know which point on the lens the measurement needs to be made to. I believe it's the 'rear principle point' which doesn't have to be within the physical lens at all - just as well or focal lengths below ~40mm would be impossible on SLRs.
See Focal length - Wikipedia

 

[Space Face]

I'm currently having a right good look at the Samyang XP 85mm f/1.2, which seems to equal and even out do the Sigma 85mm Art f/1.4 and the Canon 85mm f/1.2L ii in some respects and at around 1/3 of the price of the latter. It's MF but certainly the reviews I've seen say it's an astounding piece of glass.

 

[Soocom1]

Your not understanding what I am talking about.

Registration distance is the distance from the focal point to the image plain for those not knowing.

Your definition of registration is different from that I've met all over the place in the past, both on-line & in print, and doesn't describe a constant distance let alone a feature of the lens. Registration is usually used to mean the same as back focal length, the distance of the image plane from the mounting flange of the lens.

The minimum distance of the image plane from the focal point (ie along the lens axis) is dependant on the distance being focused and the lenses focal length. When focused at infinity the image plane passes throught the focal point (by definition), When the image size is the same as the subject size (1:1 macro) the image plane is one focal length behind the focal point, by the time the subject is at the front focal point the image distance is at infinity.

No your correct. I meant to say mounting distance.

 

[wfooshee]

The focal length makes no difference to the distortion -

Sorry, but this is quite incorrect. To prove it, shoot the subject with them at the same size on-camera at 24mm and then again at 105mm. Huge difference due to the focal length.

No, the huge difference is due to perspective from different shooting distances. If you shoot both lenses at the same distance, then crop the image from the 24mm to match the 105, you will have the same image, assuming the resolution is still there after the crop.

The distortion comes from subject to camera distance, i.e. perspective, and NOT from the focal length of the lens. When you said "at the same size," you forced a change in the camera to subject distance, which is the cause of the perspective change. The 24mm lens did not cause the exaggeration of facial features, moving closer caused that.

EDIT: I now see that Petrochemist already answered this. Oopsie!

 

[Pixeldawg1]

The focal length makes no difference to the distortion -

Sorry, but this is quite incorrect. To prove it, shoot the subject with them at the same size on-camera at 24mm and then again at 105mm. Huge difference due to the focal length.

Only as you move to reframe the subject to the same size. It's the movement that makes the difference.
.

Isn't this what I said? You would have to move the camera and make the subject the same size in both images.

 

[wfooshee]

But it's moving the camera that changed the perspective, not the different focal length. The focal length accommodates the camera position.

Shoot an image at 105mm, shoot another at 24mm, without moving the camera, then crop the 24mm image to match the 105. They will be the same, because the camera hasn't moved.

To get the different lenses to show the same size image, you do have to move the camera, but moving the camera is what changes the perspective, not using a different lens. Shooting both at the same distance and cropping the one to match the other will yield the same image (assuming you have enough resolution for the crop.) It's the distance, not the lens, that makes the change in the images.

 

[greybeard]

Like my signature says, shoot loose and crop. Many people don't realize that cropping a picture with from a 50mm will give you the same perspective as an un-cropped tele.

 

[AlanKlein]

Like my signature says, shoot loose and crop. Many people don't realize that cropping a picture with from a 50mm will give you the same perspective as an un-cropped tele.

But you lose real estate so enlargements are grainier and not as clear.