When it comes to discussing lenses, sharpness is a topic that receives significant attention, particularly in wildlife photography. The pursuit of sharp images is a common goal, with bird photography enthusiasts, for instance, emphasizing fine feather details. However, the question arises: How much does lens sharpness truly matter in wildlife photography?
Lens sharpness refers to a lens’s ability to capture and resolve detail on the subject. However, it is important to note that lens sharpness is not a single, fixed metric. A lens can exhibit varying levels of sharpness depending on factors such as aperture and the specific portion of the frame being considered. For example, let’s examine the sharpness measurement of the Nikon Z 50mm f/1.8 S lens using Imatest:
In laboratory tests, this lens has proven to be one of the sharpest lenses ever tested. However, even with such high sharpness, the results show that sharpness can differ based on the aperture used and the specific area of the frame being analyzed. Like most lenses, the Nikon 50mm f/1.8 S is sharpest in the center and typically reaches its optimal sharpness within a range of aperture values, often referred to as the lens’s “sweet spot” (in this case, around f/2.8 to f/5.6).
The sharpness and resolving power of a lens are influenced by its optical design. Generally, more modern and complex lens designs tend to offer improved sharpness and fewer aberrations. Expensive and exotic telephoto lenses, such as 300mm f/2.8 or 600mm f/4 lenses, are often considered among the sharpest options available today. However, there are also more affordable telephoto lenses on the market that may not exhibit the same level of optical performance. The question then arises: Does optical performance truly matter?Well…
A Sharp Lens Does Not Mean Sharp Photos!
When people talk about “sharp image,” they are actually saying that they have the details. The quality of detail is dependent on more than the sharpness that the lens.
So you shouldn’t be expecting to get the newest 600mm f/4 lens and immediately take stunning, sharp photographs of wildlife. There are a variety of other aspects to think about before you make a decision.
One of the most significant are Subject distance. When the subject’s distance is further away to the camera, details like bird feathers will be greater in relation to the frame which means you’ll get greater detail in feathers. Furthermore, being closer can reduce the effects of atmospherics on distortion.
Also, there’s the focal length that the lens has. If the subject is from you, the world’s most powerful 400mm lens isn’t comparable with an average 800mm lens in the amount of detail you’re trying to capture, as an 800mm lens magnifies your subject much more.
This is one reason it’s dangerous to evaluate lens sharpness solely by looking at sample photos, especially in the absence of raw Raw files. For instance, a near bird shot with a less expensive 70-300mm zoom appears sharper than a bird in the distance, photographed using the highest-end 300mm f/2.8.
There are other elements as well, such as:
- Speed of shutter and subject movement If you choose too slow shutter speed and you’ll see motion blur, which is a major cause of loss of sharpness!
- Focusing off: Front-focus or back-focus could make a lens that costs $10,000 look more sloppy than a point-and-shoot lens.
- Sharpening after processing: This will not magically erase detail However, it could enhance the clarity of existing details.
- Image noise: Taking pictures in low light or high ISOs can lead to loss of detail. A proper noise reduction technique can be helpful however, overdoing it could cause the problem to get more severe.
Also the final quality of detail in your photograph is dependent on much more than the actual resolving capability that your camera has.
A Below-Average Lens Does Not Mean Blurry Photos!
It’s true that sharp lenses will be able to capture more details (at the very least, if you’ve done everything else correctly). This is helpful when cropping your images or printing them a bit larger.
However, if you’re covering the frames with your subjects, and have ample sunlight, you’ll get comparable levels of detail using an affordable telephoto as opposed to a high-end exotic lens, provided that your print’s size is within a reasonable range. Let me put it this way If you’re experiencing blurry images with all modern lenses, it’s likely that the lens’s resolving ability is at fault.
Recently, at Jardim Botanico in Sao Paulo Brazil I was able to be very close to the Southern Lapwing, using my Nikon 70-300mm AF-P DX zoom. It’s a pricey entry-level zoom for telephoto, and while it’s perfectly fine however it’s unlikely to be as popular as Nikon’s premium primes. But because I had the right focus, a quick enough shutter, lower ISO and a subject in within the frame, this image is extremely sharp in close-up. The only thing that can limit the ability to make a an image that is large is the number of pixels, not the lens!
It is true that these were near-perfect conditions. If you were shooting more challenging subjects or a lot of cropping, the 70-300mm lens would have revealed its flaws more evidently. However, it is clear that a basic or even a less than average zoom lens isn’t a death sentence for sharp wildlife photographs. It is better to fill the frame with a basic lens than to enlarge it with a high-end lens.
Should You Upgrade to a Sharper Lens?
The decision of whether to upgrade your lens is an arduous issue. If you purchase an expensive or better-performing lens, its sharpness can be far far from being the only thing to increase. As an example, switching between an Sony FE 200 to 600mm f/5.6-6.3 G to the Sony 600 f/4 GM will not only give more clarity, but more efficient autofocus as well as an aperture of f/4. In reality, these enhancements contribute more to the image’s overall clarity, as opposed to the different resolution power of the two lens.
In my own journey through wildlife I shot using lenses like the Tamron 150-600mm lens. I then upgraded to a Nikon 500mm f/5.6 F/5.6 PF lens. In this instance the more efficient autofocus as well as the smaller camera’s weight were both the biggest notable enhancements, and both had direct effects on the quality of my images. Yes 500mm f/5.6 is the more sharp lens in laboratory tests, and it is evident on the street, however, there were other attributes that made a greater difference for me.
It’s not even mentioning that generally speaking the issues in wildlife photos go higher than clarity (whether lens sharpness is present or not). It’s more important to focus the lighting, and the composition (gasp!) than the pixel-level details. If the issue is more specifically is lacking in details, the most likely cause is the need to gain a better understanding of the object.
This brings me to another issue: the extent of the change. In a typical scenario, if using a smaller lens, and you have a teleconverter as well, changing to a lens that has more focal length is usually a great improvement in terms of clarity (especially in the case of an f/1.8 primary lens).
However, sharpness differences diminish as you ascend the ladder of lenses that are high-end. If you’re not getting adequate sharp images with a $2,000+ telephoto prime You shouldn’t be blamed on the lens unless you fell from the ladder.
I can remember when Libor shocked a lot of people when he pointed out that Nikon Z 400mm f/4.5 (a $3250 lens) is identical to it is the Nikon Z 400mm f/2.8 TC (a $14,000 lens). There are a number of good reasons that pros would prefer the f/2.8 prime – particularly because of the bigger aperture and the built-in teleconverter, however, the sharpness tests at the lab are not one of them.
There will be no doubt in the minds of anyone that lenses have been becoming better as time passes. Contemporary lenses, including budget ones, are more advanced than the typical lens from ten years ago. I’d have no problem using modern telephoto lenses like those from Sony 200-600mm and the Nikon 100-400mm and likely the coming Nikon 200-600mm. The lens’ sharpness could be less sharp than a top-quality prime in the lab but when in use these differences usually disappear.
What’s the best way to answer the question I asked as the subject of this piece? I’d say that lens clarity isn’t a big deal up to a certain point and we’ve got to that point using modern lenses, including the cheapest ones. Yet, if you’re looking to upgrade, an even sharper lens could be a worthwhile option for those who are obsessive about sharpness! The reason is that the sharpest lenses available (usually the expensive primes) come with other attributes that are more important. They come with larger maximum apertures, more rapid speed of focusing, more effective stabilization of images and so on. These features directly contribute to sharper pictures. If you change from 70-300mm f/4.5-5.6 to 300mm f/2.8 you’ll certainly get sharper images, but not in the way you thought.
As a last note we should all step back when we can. It’s absurd how many photographers are obsessed on sharpness these days, and I’m guilty too. I like prints that appear sharp and clear when you look closely. However, some of the most stunning photographs of wildlife I’ve seen exhibit some flaws when you’re looking up to the lens. Before you commit to in upgrading your lenses, make sure you are aware of the advantages you’ll get and what it can do for your photography.