By: Gary Gray
When I’m looking to upgrade a lens or purchase a new lens, I typically go through a tedious evaluation of the various offerings . I’ll read user reviews and test reports and the manufacturers data on every lens I consider. This process is part of my engineering DNA, something I’ve learned from many years working with digital imaging systems at The Wall Street Journal. At a base level, like most folks, I don’t have an unlimited budget and I just want the best bang for my buck and I want the best image quality that I can afford.
Once I’ve talked myself into adding a lens to my kit, the first place I start is to compare the optical quality of my current lens with the optical quality of my available selections for an upgrade as well as compare the different selections using the same criteria across brands or models. My optical performance comparisons almost always start with the manufacturers MTF chart for that lens.
Here’s a quick primer on MTF charts. I’ll use the Nikon 200-500mm f/5.6 ED VR super-telephoto zoom compared to the Nikon AF-S 500mm f/4E FL ED VR. A $1,300 lens vs a $12,500 lens.
The prime lens will only have one MTF chart, because it only has one focal length. The zoom lens MTF chart will show the wide end and long end of the lens performance.
To simplify the understanding of the MTF chart, think of the left side of the chart as indicating lens performance in the center of the lens at maximum aperture and as you move to the right along the x axis, the performance is graphed towards the outer edge of the lens.
The lines are representative of overall lens contrast and sharpness based on the portion of the lens frame being measured. The measurement includes both horizontal and vertical contrast levels (dotted lines) in the lens as you move away from center and shows how much divergence the lens experiences from center to edge. In a perfect world, the lines would all be tightly grouped together from center to edge and there would be no change in distortion near the frame edge. The more those lines dip down and separate from each other on the right side of the chart, the lower image quality at the edge of the lens frame vs the center. Looking at the 500mm prime, you can see that the lines stay tight and just barely move down at the extreme edge of the lens frame. This is about as good as you can get in any lens. That’s why it costs $12,500. Looking at the 200-500 on the telephoto (right) chart, you can see that as one moves from the center of the image frame towards the edges, the horizontal and vertical components of the image quality begin deteriorating somewhat. Still, the lines are fairly close and the loss isn’t significant for a zoom lens. You can also see that the performance of the 200-500 is even better on the wide end (200mm) of the lens frame. For a $1,300 lens, it does quite well.
So, when you are choosing a lens and want to know what the image quality is going to be relative to another lens, call up the manufacturers website and find the MTF chart on the lenses you are researching. You can compare the different lenses on the same general playing field this way. Most zoom lenses are sharp in the center but they begin losing image quality as you move towards the edge of the lens frame. Zoom lenses are are a compromise of price and performance. Minor differences are just that, minor. A really good prime will almost always outperform a really good zoom. Yet, zooms are still good choices in a lot of circumstances for the reasons I’ll spell out later in this article.
Of course, the technical data regarding any particular lens doesn’t give you a complete understanding of how that lens is going to work for you in the field. One has to consider a number of factors when evaluating the lens. Price, weight, functionality, build quality, auto-focus performance, stabilization performance, etc.
My current kit consists of Nikon full frame DSLR bodies, so my article is going to be based on lenses made for the Nikon F mount; however, you can make this same evaluation for any brand of camera and lens. I’ll through in a few observational experiences and opinions along the way.
I have two basic interests in my photography. I am a landscape photographer and a wildlife photographer, and as such I make my lens selections based on those two disciplines. The general lens performance characteristics I look for are not the same between landscapes and wildlife. There is no one size fits all in my mind. Different jobs require different tools.
For the purposes of this article, I’m going to concentrate on lens selections for wildlife photography. Perhaps I’ll write something about landscape lenses in the future.
For wildlife photography I find the most useful focal lengths to be telephoto to super-telephoto. Reason being, I normally want to get as much of the animal in the frame of my image as possible. I also want that animal to appear sharp and crisp. I like to count the hairs on their nose or the ripples in their feathers. My field kit normally consists of two full frame cameras, one mounted with a 70-200mm zoom lens for animals in close proximity and the second camera mounted with a super-telephoto zoom, in my case a 200-500mm lens for those animals at a further distance.
If you are lucky enough that the price of your photography gear isn’t an issue, investing in expensive lenses is fine. Prime lenses and some high end zooms will give you all the performance money can buy. Yes, exotic primes, as a rule of thumb, will provide you with better optical performance, but at a price. The price you pay is in dollars and in flexibility. I use zoom lenses most of the time. Personally, since I intend to make a profit from my photos, I look at the payback point of any lens I buy. How many salable photos do I think I can get from any given lens vs the purchase price for that lens. In my mind, paying for an exotic prime that costs upwards of $7,000 or more has to be offset by the number of really good photos I’ll get from that lens. If, for example, I can earn $100 per photo, how long will it take me to make that lens profitable. In other words, how long will it take for the lens to pay for itself? In the business world, and photography is a business to me, quite a bit of my evaluation and selection process hinges on “return on investment.”
If I pay $7,000 for a lens, how many photos from that lens do I have to sell and how long does it take to sell them, to make the lens a worthy investment. I’ll assume an arbitrary period of time as being 5 years of sales. For that $7,000 lens to pay for itself with photos that make $100 in 5 years, I’ll have to create an average of 70 salable shots in that same period of time. Alternately, a lens that costs $1,500 will require I create 15 salable shots over 5 years to reach my return on investment. Obviously, a cheaper lens is more cost effective, assuming you are getting salable images from that lens.
Customers could care less which lens you use. All a customer cares about is what the image looks like. Is it a good composition that meets their needs and is the quality of the image good enough to meet their needs? Customers aren’t out there asking “was this photo taken with an expensive lens?”
Another aspect of zoom vs prime lenses is flexibility. Over the years out in the field, I’ve seen a lot of photographers dragging around large exotic prime lenses mounted on huge tripods with expensive gimble heads and other accessories required to maintain that type of kit. I see it all the time. The photographer arrives on scene, they break out their tripod and gimble head, find a spot, set it up, get their gigantic exotic prime lens out of its protective case, mount it on the tripod, attach the camera to the lens, get everything aligned, leveled and pointed in the direction of the animals. If they don’t like their setup, they have to fold up the tripod legs and lug a 20 pound setup somewhere better, and that too almost always happens. Meanwhile, they are making a lot of noise, waving a lot of gear around and the moose is patiently standing there waiting for them to get their act together so it can pose for a nice photo. NOT. They’ll get a hand full of shots and then have to move because that prime lens is only going to give them a single field of view and, well, how many shots of a moose nose do you really need?
After a while, the photographer takes the big exotic prime off the tripod and just keeps it in their hands and learns to work a little faster and more quietly, hand holding a camera and lens that weighs over 10 pounds for the few seconds they can tolerate the bulk and weight. Next, they’ll understand the folly of the setup and they abandon the big exotic prime and expensive tripod, put a lighter zoom on the camera and work with that setup because it’s lighter, faster and more flexible. The end result is of course, that $10,000 lens/tripod setup gets stuffed in the back of the truck and that $1,500 lens gets most of the use.
I also believe there’s a certain “photographers vanity” associated with lens selections. I once had a fairly well known professional wildlife photographer tell me “when are you going to get a nice prime lens for your kit? You’ll never be taken seriously as a wildlife photographer if you don’t have a big expensive lens.” What? My thinking at the time was “I’m not really interested in impressing the other photographers who watch me work with how much money I spent on my gear.” Yeah, for some, it’s a vanity thing for sure. Having a big expensive lens on a expensive camera mounted on an expensive tripod is the best way to impress those around you when working. I responded with “Really? How long is it going to take for that lens to pay for itself?” I got no answer. Meanwhile, while he was lugging his behemoth rig around I was getting photos with my hand-held zoom lens. Good photos too.
For all my previously stated reasons, I find that zoom lenses are cheaper, more cost effective and I get more salable photographs from them. That’s why I use zooms over primes. People watching me work and going ohhh, aaah, about my gear is the least of my concerns.
All that said, what are your best considerations for a wildlife lens? Here are my thoughts.
You don’t need f/2.8 lenses. Yeah, they are great in really low light and give you a little faster shutter speed at a lower ISO, sometimes. Today’s cameras can generate excellent images quality up to ISO 3200, so that extra stop of aperture isn’t really solving a problem in today’s world. Plus, depth of field at f/2.8 isn’t really suitable for a good quality in-focus image. I almost always set my lens aperture for f/7.1 shooting wildlife. The only exception is in the very early hours of the day before the sun rises or after sunset when I may bump the aperture to f/5.6, but honestly, it’s a fools errand shooting in such low light to begin with. Good photographs involve good light, so shooting in the dark is not something that generates a lot of really nice photos. F/2.8 isn’t really solving a problem, it’s just making you feel all warm and fuzzy about working in crappy conditions. I use f/7.1 as a starting point because I get the depth of field I like to see when I focus on the eyes of an animal. The eyes are sharp, the entire head is in focus and I don’t get many focus misses at that DOF. If there are more animals I want to get in the frame, I stop down accordingly to get more depth of field. F/2.8 doesn’t solve that problem, it just makes it worse.
Here are a select few the basic telephoto zoom lens choices you’ll have in today’s world, meaning the year 2020. Now I’m not shooting mirror-less so the Sony and other mirror-less shooters can extrapolate to what is available. Just check those focal ranges and MTF charts before you whip out that credit card. I’m going to discuss lenses that cost $3000 or less. If you have money and want something a little better, it’s not hard to do.
For the Canon shooters.
Canon EF 100-400mm f/4.5-5.6L IS II
If I were a Canon shooter (and I used to be), this would be the first lens I would buy. It’s versatile, sharp, light and has very good image quality. Stay away from the older push-pull 100-400 L. It’s not all that sharp and failure prone. You can still find them on the used market but they aren’t worth fooling with. I know this from experience.
Canon EF 70-200mm f/4L IS USM and f/2.8L IS II USM (and other variations)
These are optically good lenses and you can pick up just about any version new or used and get good results in this focal range. I prefer the image stabilized versions, but even the original 70-200 f/2.8 L without stabilization is quite hand-holdable with excellent image quality. Great for a second body.
Canon EF 28-300mm f/3.5-5.6L IS USM
Old and unimproved, I don’t know why Canon continues to make this lens. It’s not sharp, it’s expensive, it’s bulky and just not worth fooling with.
Canon EF 70-300mm f/4-5.6L IS USM
It’s sold as a high quality L lens, but quite honestly, the focal range looks appealing but Canon hasn’t updated this lens in years and it’s just not that good optically. I had one for years and simply hated it. I’d skip it.
Canon EF 70-300mm f/4-5.6 IS II USM
A consumer grade lens that is almost as good optically as the L version at half the price. If you don’t have a lot to spend, this one is a better buy than the L version. I still don’t like it. It seems that Canon and Nikon both offer the 70-300 focal range zooms and none of them are go-to lenses in my opinion. For people on a budget and who want a very light kit.
For Nikon Shooters.
AF-S NIKKOR 28-300mm f/3.5-5.6G ED VR
Consumer grade lens, I consider this a travel lens but I suppose it could be suitably used for wildlife. Lousy MTF on the wide end, a little better at 300mm. Good for the budget minded.
AF-S VR NIKKOR 70-300mm f/4.5-5.6G IF ED
Better on the crop bodies, it just doesn’t cut it on a full frame camera beyond 200mm. It will work in a pinch though, just don’t plan on top quality image quality at 300mm, which sort of defeats the purpose of having a lens that goes to 300mm. Dirt cheap on the used market though.
AF-P NIKKOR 70-300mm f/4.5-5.6 E ED VR
Nikon’s best offering in this focal range and at a reasonable price. A good one lens solution or on a second body. Stay away from all previous versions. This one is worthy of having in the kit.
AF-S NIKKOR 70-200mm (Various versions)
All good. Nice and sharp, hand holdable and excellent image quality from any of these lenses. Buy the one that fits your budget. I use the f/4 G version on a D750 and am quite satisfied with it.
AF-S NIKKOR 80-400mm f/4.5-5.6 G ED VR
This is a solid lens with good image quality out to 300mm but at 400mm it becomes a little too soft for my tastes. I know a lot of photographers who use this lens and are quite happy with it though. If you’re considering this lens, I’d recommend the 200-500mm over it because it’s cheaper and optically as good or better in some instances. Stay away from the older versions of this lens on the used market. They aren’t very good.
AF-S NIKKOR 200-500mm f/5.6 ED VR
This is my main wildlife lens. Optically, it’s producing good quality images out to 500mm, it’s quite hand-holdable and very affordable. The build quality is more consumer grade and some of the design elements are a little bit cheesy, but for the price, this would be the first lens I’d consider adding to the kit.
Sigma 60-600mm F/4.5-6.3 DG OS HSM|S
A newer offering from Sigma, it has a versatile focal range and decent image quality. A bit of a compromise across the focal range but you can get usable images from this lens. At almost 6 lbs in weight, it’s not that light a lens, but can be used hand-held by those with strong arms and hands. It replaces the old “Bigma” 50-500mm, which I’d avoid buying used.
Sigma 70-200mm f/2.8 DG OS HSM|S
Optical quality is good enough and it is priced lower than the Canon or Nikon counterparts. If you’re looking to save some money on this focal range, it’s worth considering. The auto-focus isn’t as good as Nikon or Canon though. You won’t get as many keepers. It isn’t that heavy so it can be used hand-held without much concern.
Sigma 100-400mm f/5-6.3 DG OS HSM|C
A usable lens with decent optical quality out to about 350mm but at 400mm it starts losing sharpness. Very light weight and solidly built for a consumer grade lens. If you’re on a budget and want to keep just a few lenses in a pack, this might be worth looking at. I’ve shot with this lens and the only real gripe I had about it was the auto-focus being a bit slow.
Sigma 120-300mm F/2.8 DJ OS HSM|S
A little bit on the pricey side, the MTF indicates this lens has pretty good optical quality. The focal range is a bit more limited and seems to be better suited as a sports lens, but it would be quite usable for wildlife photography. A better choice than any 70-300mm on the market, but you may need an additional lens for wider angle telephoto shots.
Sigma 150-600mm f/5-6.3 DG OS HSM|C
An excellent consumer grade lens for the price. It’s primary competition is the Tamron 150-600mm. The optical comparison is roughly identical between the Sigma and Tamron. If I had to choose between the Tamron and Sigma, I think the Tamron would be the better choice as it holds a little better image quality at 600mm. The Sigma probably holds up a little better at the wide end. The auto-focus performance isn’t anything to write home about though.
Sigma 150-600mm f/5-6.3 DG OS HSM|S
The more expensive “Sport” version of the Sigma offerings in this focal range. It’s a bit heavier and has a more sturdy build than the C version of the lens. Optically, not much difference with the cheaper lens, being perhaps a little sharper in certain situations. If you’re in to spending quite a bit more for very little more, other than weight, this would be a suitable lens for wildlife photography. Personally, I’d save the money and buy the Tamron or the Sigma C version. While I haven’t tested it, the word is that the auto-focus on this lens outperforms the C version and the Tamron offering. That alone could be worth paying for.
Tamron SP 70-200mm F/2.8 Di VC USD G2
Optically quite good with just a little bit of image deterioration at 200mm, but nothing to loose sleep about. The problem I’ve always had with Tamron lenses is the performance of the auto-focus. For the money, a good alternative to the OEM versions.
Tamron 70-210mm f/4 Di VC USD
An even newer and cheaper version of the Tamron lineup in this focal range. You get an extra 10mm of focal length and a much cheaper lens. A bargain basement lens in my opinion. If you absolutely need this focal range and don’t want to spend more than $500, this is your puppy. Optical quality isn’t as good as any other 70-200mm offering, but that price is mighty attractive. It’s still good enough to get you by though. Ultimately, you’ll ditch it and get something better.
Tamron 100-400mm f/4.5-6.3 Di VC USD
Tamron’s answer to the Sigma 100-400mm and a little better optically than the Sigma. Plus it comes with a tripod collar, which isn’t included with the Sigma. This lens is also about $200 more expensive than the Sigma 100-400. You’re paying a bit more for better optical performance and a tripod collar. The reports are that the auto-focus is fast and quiet. What more could you ask for? A good, light addition to your kit on a budget. It may be all you need.
Tamron SP 150-600mm f/5-6.3 Di VC USD G2
Tamron’s latest iteration of this consumer grade super-telephoto. There’s an earlier model, A011 which is commonly available as well. Of the two, the newer G2 version of this lens is superior, mostly on the frame edges. Optically, both are quite adequate for getting good quality photographs, though they do begin losing sharpness by 600mm. I compared my Nikon 200-500 VR to the A011 version some time back and the Tamron was pulling more detail at 600mm than the Nikon did at 500mm, though just by a tiny bit. The biggest issue I have with these lenses is the auto-focus performance. Neither perform well enough to be reliable birds in flight tools, but still, it’s possible. Otherwise, you can use either to photograph any type of wildlife reliably that isn’t fast moving.
So here is my recommendations for folks who are more worried about their budget and want to still get a good quality photograph in most situations.
Canon shooters should go for the EF 100-400mmL IS II and perhaps one of the 70-200mm L offerings.
Nikon shooters should be looking at the 80-400mmVR II or the 200-500mm VR. Any of the 70-200mm offerings will cover the wider focal lengths as well. Avoid the 70-300mm offerings unless you absolutely can’t afford more lenses, in which case the AF-P NIKKOR 70-300mm f/4.5-5.6 E ED VR would be my recommendation.
Both Canon and Nikon shooters can get satisfactory results from either the Tamron 150-600mm or the Sigma 150-600mm C offerings. I’d recommend the Tamron over the Sigma though. If you want a one lens solution, go for the Sigma 60-600mm.
The Tamron 100-400 may be a good substitute for an L lens or the Nikon 80-400 but it’s not going to be a high performer with birds in flight. If the budget is really tight, you can pick up the Tamron 150-600mm 011 version used for under $700 and you’ll get satisfactory results in most situations, short of tracking birds flying quickly towards or away from you.
For most situations, you don’t need more than 400mm of focal length for good wildlife photography. As a matter of fact, with focal lengths covered from 16mm to 600mm in my kit, 76% of the wildlife photo’s I’ve taken over the past 15 years are at or below 400mm. Having a 500mm or 600mm lens is gravy, and having that much reach is a luxury for the most part. If you want to shoot a lot of birds in flight, the OEM lenses are your better choice and also where those 500mm and 600mm lenses pay off. Birds are tiny things for the most part, and you aren’t likely to get very close to them.
Canon and Nikon’s auto-focus systems are superior to Sigma and Tamron, in just about every instance, and so are their prices. You pay more to get better performance.
Keep in mind also the difference between crop sensor bodies and full frame bodies. I use full frame because the overall image quality is superior in just about every instance. The crop bodies do give you a focal length multiplier though (1.6 for Canon, 1.5 for Nikon) which will give a 400mm lens an effective focal length of 600mm plus. You’ll be giving up a lot with a crop body though. Image resolutions are typically worse, noise is usually higher and most crop sensor bodies don’t have top notch auto-focus systems. But, on a budget a modestly priced crop sensor body such as the Canon 90D or the Nikon D7500, when coupled with a 100-400mm telephoto zoom lens, and you’re in the game at a fairly low price point.
And there you have it.