I was teaching a webinar the other evening and I got a question that prompted me to write this post. Now, I’ve actually gotten this question many times before, but this is the first I’m writing about it.
See, during the webinar I had mentioned that I “mostly” photograph birds with the lens wide open – that’s just another term for the lowest f-stop number that the lens will allow you to go to. This does several things:
- Allow’s more light in, which leads to lower ISO needs
- Allows you to shoot at faster shutter speeds, because you’re allowing more light in
- Allows for a more shallow depth of field, meaning that what you focus on will be sharp, but the backgrounds will go blurry and make your subject stand out.
- But as you move away from that focus point things will fall out of focus and become soft and blurry. Sometimes a good thing, sometimes not.
But some one asked a question that I’ve had asked many times over the years. It goes something like “Shouldn’t you avoid shooting the lens wide open because 2-3 stops past that is really the sweet spot / sharpest point on the lens?”. For example, if you have a lens that will shoot at f/2.8, you should really shoot at f/5.6 or even f/8?
The only way I can answer that question is based on my experience and looking at settings of others. I realize that there are charts out there and measure-baters (that’s a fun nickname we call a certain type of person in this industry) that will do long write ups on the technicalities of this, while they demonstrate with pictures of a rusted chair in the backyard of their home.
Is it true? Probably. But avoiding certain apertures is more true when it comes to diffraction and shooting at higher f-stop numbers than lower (though I shoot 100% of my landscapes at f/16 and nobody walking through my home ever thinks they’re not sharp). So not really something we’d have to worry about in wildlife photography.
But the lower end of the f-stops is really where this specific question comes from. For me, I have two thoughts.
Thought #1: Depth of Field
When you photograph a bird close to you at f/2.8 or f/4 (or even higher) you may get depth of field issues. This means that if you focus on the eye, the back of the head, wings, etc… may be out of focus. This effect is actually semi-desirable in portrait photography, but for some reason critiquers in bird photography frown up on it. See the Osprey photo below.
This Osprey was probably 10-15 feet away from me sitting on the side of a bridge I was driving over. I stopped, grabbed my Sony a7R4 and 200-600 at the time and zoomed in and took a full frame photo at f/6.3. As you can see, the osprey’s eyes are RAZOR sharp, but there is some depth of field fall off everywhere else because I was so close and at such a low f-stop number. Personally, it doesn’t bother me much and I actually like it in many photos.
But when I posted this to a website that I sometimes visit for critiques, everyone commented on the DOF and how I should have photographed it at f/11 so details were sharp all of the way through.
We can debate on the whether or not we all agree with this but that’s not really the point. There are indeed times where you may not want the shallow depth of field from shooting wide open, whether it’s because of the photo above, or because maybe you have several subjects that are in front/back of each other and a higher f-stop number is more appropriate.
Thought #2: So You Mean I’m Supposed To Pay What???
My second thought is a little more practical in nature. When some one says this to me, my reply is often: “So you mean, I’m supposed to pay upwards of $10,000 for a long zoom lens that lets me shoot at f/2.8. But… I’m actually not supposed to shoot it at f/2.8?… are you freaking INSANE???!!!”
This makes absolutely ZERO sense to me. And whenever I ask a tech or engineer with a camera company they often agree and fully recommend shooting the lens at whatever aperture you want to shoot at.
Here’s an example. Let’s zoom in to the photo above. Remember, it was taken at f/6.3 – the lowest aperture the lens can go to (gasp!!!). Do you see a sharpness problem? I’m hand holding 600mm from a car. And you’re telling me I shouldn’t shoot at this aperture because it’s not sharp?
Work With Me Here
So let’s work though this logic. You’re telling me I should shoot my $10,000 f/2.8 lens at f/5.6 or even f/8 because it’s not sharp at f/2.8. Okay great. Well, once I switch to f/8, my shutter speed will naturally have to be longer to compensate, so I still get a good exposure right? Okay, well, if that happens now I risk getting a VERY motion blurred photo that is clearly blurry even without zooming in on it – not just blurry according to a chart on DXOmark.com
So how would I avoid that? Well, I’d have to lock in f/8 and a fast shutter speed which could yield a very under-exposed photo. In which case the only way to get it well exposed would be to up the ISO. So now, rather than a minutely soft photo from shooting at f/2.8, I have a photo at f/8 that’s shot at 6400 ISO. And now I have to do noise reduction on it which is great, but I’d rather have a clean photo (that doesn’t require noise reduction) any day if I can.
For me, this idea is absolutely ludicrous. You buy a lens that shoots at a certain aperture for a reason. Don’t cripple that lens, and not use it to its full capabilities. If you want to shoot at f/8 or even f/11 or higher for creative reasons, have at it. I totally understand and I even do it myself sometimes. But please please please, don’t risk blurry or noisier-than-needed photos just because of an article you read on the internet.
Personal Responsibility – Try It Yourself
Most of you reading know I throw the words “personal responsibility” out there a lot. If this is something you’ve read or heard about, and you’re not quite sure if it’s true or not, or how it will affect your specific lens, then you own it to yourself to do your own tests. Take the lens out to your backyard, and set up as close to your normal shooting situation as possible. If you usually handhold, don’t put it on a tripod. If you’re usually on a tripod, then don’t handhold. Then do some tests on something that’s still. Shoot one photo wide open, and shoot another 2-3 stops above that. Layer them in Photoshop and see what you find. Try it yourself and let your personal tests and results speak for you.
And lastly… look around the internet at wildlife photos you like. Find the pros that you follow and look at their settings? Do they shoot wide open? I bet they do. At least the ones I follow do, but look for yourself and I bet you’ll see that many of your favorite wildlife photos were taken with the lowest f-stop number their lens will offer.
If you concentrate on anything, I’d suggest forgetting this topic and concentrating on getting yourself in to a great place for bird photography, in great light, with a great subject. I promise you 100% that if you do that, and look at your photos later, you won’t think twice about the “sweet spot” for your lens. Thanks!