Why Are Some People In My Group Portraits So Soft? – Q&A with Matthew Saville
What is the best way to get family portraits in focus, without totally sacrificing shallow DOF? Sometimes people on the edges of the portraits are juuuust out of focus, but I’m already at f/4 or 5.6 and it just seems like everybody should be sharp.
As awesome and sharp as all the latest pro zoom lenses are, they have in my opinion caused two very big problems among photographers today: Firstly, they have made many photographers lazy with regard to hyperfocal distances, or at least having a solid understanding of depth and apertures in general. Myself included, by the way! Secondly, even though the latest pro zoom lenses are incredibly sharp in general, the wider angle lenses often have significant issues with field curvature and distortion, and are simply not well-suited for family formal photos especially at “fast” apertures. But what the heck is “field curvature”?? Don’t worry, it is exactly what it sounds like- your “field”, or plane of focus, is curved instead of flat. Either by design or due to quality control, or simply because of heavy abuse by hard-working pros, …one way or another any lens wider than 50mm need to be used very carefully for group photos.
Test Your Lenses!
First, aside from the technical stuff (which we’ll get into next) I want to present everybody with a little bit of tough love regarding the situation overall. Simply put, GET OUT AND TEST YOUR GEAR! This is the critical step in mastering your craft in general, and the responsible thing to do as a professional. You can read online articles all day long and look at test images etc, but unless you actually go out with your camera and start testing, you’ll never know for certain whether your camera or lens has a problem, and what to do about it.
So grab a tripod if you have one, (always good for eliminating factors of uncertainty during any sharpness test!) …and try things out. Recruit some friends if you have to. I’m betting there are a few other photographers in your area who shoot portraits and would like to learn about how to get the sharpest possible photos!
We’ll probably have future articles that are dedicated to “how to test your lenses”, of course!
Understand Depth Of Field For Group Photos
Now let’s discuss depth of field, (DOF) and how it relates to focal lengths and distances. Firstly, every photographer should know that the more you zoom out, the less “shallow” your DOF is going to be. In fact using a super ultra-wide lens or a fisheye lens, pretty much everything is going to be in focus unless you intentionally try to focus on something that is just inches away from your lens!
…Which brings me to my next item. The closer you focus, the more the background will blur. Now before everybody says “duh!” let me add this: You don’t necessarily have to focus “close” to your subject to achieve lots of background blur. All you need is to make sure that the distance between you and your subjects is less than the distance between your subjects and their background.
For example, if I were doing group photos outdoors, I would rather photograph my subjects standing in an open space with a very, very distant background at f/2.8 or f/4-5.6 even, …than photograph them at f/1.4 or f/2 in a space where the background is just a few feet behind them.
Of course keep in mind that I’m assuming you’re trying to achieve shallow DOF, and that is an assumption that will remain for this entire article. Obviously there are situations in which getting your background in focus is a very good thing.
But I digress. Learn how to find shooting environments and compositions that offer you the best chances of achieving background blur. For example if you’re photographing full-body portraits of a group of 5-10 people, I would prefer to have a background that is at least ~50 ft behind them. Obviously this isn’t possible in a church, but outdoors it is frequently doable.
The next thing to worry about is your focal length. I actually prefer to shoot group portraits with as long of a focal length as I can manage, even as long as 50mm or 85mm sometimes if I have enough open space. Yes, there is a lot of backing up involved in shooting a group of 5-10 people at ~85mm, but it is worth it!
Nikon D700, Nikon 70-200mm f/2.8 @ ~80mm & f/2.8
Camera-To-Subject Distance: 20-30 ft
Subject-To-Background Distance: 40-60 ft
The absolute best way to achieve shallow depth while still getting tack-sharp
group photos is to shoot at f/2.8 or f/4 on a 70-200 or 85mm
I usually only go wider to 35mm for capturing groups that are 10-20 people in size, or for capturing groups of 5-10 in closer quarters.
Nikon D700, Nikon 24-70mm f/2.8 @ ~40mm & f/4.8
Camera-To-Subject Distance: 20-30 ft
Subject-To-Background Distance: 40-60 ft
At about 10+ subjects, I stop worrying about shallow DOF
and focus on achieving zero distortion and good sharpness.
I try not to use 20-24mm unless I am indoors and truly constricted on space. If you’re shooting a bunch of groups of 3-10 people and then all of a sudden you get a group of 20 distant relatives in one photo, it may seem easier to just stay where you are and zoom out all the way on your 24-70mm. However if you try to shoot a group photo at 24mm and you have people’s faces at the edge of the frame, you’re going to be distorting them very significantly. The people on the edge are going to look a lot “wider” than the people in the middle of the photo.
As a rule of thumb, if I have to zoom out to 24mm or wider for a group photo, I try and make sure that I am including extra space on the left and right edges. At least enough space for an 8×10 crop, and maybe even a square crop if the particular lens I am using is rather nasty with regard to field curvature or edge distortion. So yes, I would rather zoom out to ~18mm and have all my subjects be much closer to the center of the frame, than have someone’s face be just a few pixels away from the edge of a 24mm frame. Especially if I have 24-36 megapixels to work with in post-production! However again, keep in mind this is an “emergency” type situation already. Whenever possible, I try and shoot even the largest groups at 35-50mm.
Full-Frame Versus Crop Sensors – For Formal Portraits
While some photographers may encourage you to get a full-frame camera, you’ll actually get MORE DOF on a crop sensor at the same aperture, which is quite nice as long as you have the right lens and working distance in order to blur your background.
The main issue with crop sensor cameras is that their wider angle lenses are usually a little bit more exotic with regard to their optical design, and they can cause significant distortion and/or field curvature. A lot of people choose full-frame simply because the lenses that exist for full-frame are more “people friendly” when you need to place someone’s face at the edge of a photo at a medium-wide angle focal length.
In my opinion, having a good understanding of distance, DOF, and focal length is more important than one sensor format versus another. So you’re welcome to save your pennies and upgrade, however don’t blame your sensor format for soft or distorted group portraits!
The Perfect Plane Of Focus For Group Portraits
Quite honestly, sometimes what it comes down to is getting all your subjects to line up or lean in perfectly. However instead of pestering your subjects to shuffle back and forth all session long, it helps if you can explain your reasoning to them. Personally I just flat-out tell my clients that they will be out of focus unless they take a step forward or backward, and/or “lean in” a little bit.
The key is to get your subjects on your side and have them help you out. I like to be just a tiny bit of a camera geek in front my clients, because it seems to help them become more proactive about achieving a flat plane of focus for me. Of course you don’t want to get too geeky or use big words just to sound impressive, usually a simple “can you lean in a little more so you aren’t out of focus, please?” works fine, or “alright I want everybody in this group photo to be totally in focus, so can I have the three people on the end take a couple steps back?”
Of course we haven’t even gotten into focusing and that whole aspect of sharpness at all, which is such a huge subject that we could probably consume a dozen articles on it alone. For now, check out this article here for Six Tips for DSLR AF and Sharper Images.
Lenses With Low Field Curvature / Distortion
- Nikon 24-70mm f/2.8
- Canon 24-70mm f/2.8 (mk2)
- Sigma 35mm f/1.4 EX DG ART
- Nikon 35mm f/1.4 G
- Nikon 50mm f/1.8 G (and pretty much any Nikon 50mm prime)
- Sigma 50mm f/1.4 EX DG
- Nikon 70-200mm f/2.8 (and pretty much any Nikon 70-200mm lens)
- Canon 70-200mm f/2.8 L IS (and pretty much any Canon 70-200mm lens)
Lenses With Moderate Field Curvature / Distortion
- Canon’s mk1 24-70mm 2.8
- Nikon 17-55mm f/2.8 DX (Unless it is perfectly calibrated)
- Canon 35mm f/1.4 L
- Canon 50mm f/1.2 L (and pretty much any Canon 50mm prime)
Lenses With Significant Field Curvature / Distortion
- Canon 16-35mm f/2.8L II
- Any Sigma ultra-wide lens, such as the Sigma 8-16mm f/4.5-5.6 EX DC
- Any lens that has not received proper optical calibration.
Hopefully there are a lot of experienced photographers out there who are shaking their heads and saying to themselves “well duh, you shouldn’t shoot a group photo at 16mm on full-frame, everybody knows it will distort people at the edges and make them look twice as large as the people in the center of the picture!” Indeed, field curvature or no field curvature, I think I’ve made it clear that zooming out should only be reserved for when you absolutely have no other option. If you’re aspiring to be a portrait or wedding photographer, you should definitely invest a lot of time into testing your lenses and finding the best way to achieve sharpness across your entire image!