The Tamron 55BB Mirror lens was introduced in 1983! It’s a camera lens that is definitely not your typical birding lens, and not one I would even recommend. In fact, this post is just to prove that it is theoretically possible to capture good images with it. Given that it is not that expensive compared to modern lenses on eBay when it does show up at all, it may be a fun experiment to try to bird with this lens.
Back in the day, this lens was considered to be a pretty cool lens. In that day, there were no superzooms or compact far-reaching cameras like the Nikon P950 or even the added reach you get with high-density crop or micro 4/3rd sensors in good light. In fact, if you check some of those old Audubon field guides from the 70s and 80s, you might even find pictures taken with a mirror lens like this one, right in a published nature book! Yeah!
But there are so few reviews on the internet with regard to this lens and birding, that I thought I should post one. The pictures that are out there often do not show this lens with regards to birds, or if they do, the pictures are typically made by someone who gave up on this lens too soon! I don’t blame them though because it’s really hard to use.
It’s extremely compact. It’s not much more noticeable than one of those modern 50mm f/1.4 heavy primes people are always raving about like the Sigma Art f/1.4. So, I can put it in exactly the same bag that I put a DSLR with a fast fifty attached. Wow. That is compact. No non-mirror lenses can really boast this level of compactness.
Handling is great. The focus ring feels like it belongs on a Mercedes, not that I’ve ever driven one of those. Too expensive. But it’s really smooth, like on high end supertelephoto primes! However, at medium to far distances, it is a little hard to manual focus, but that’s just the nature of the beast.
Oh yeah, this lens is an Adaptall-2 SP lens. That means it comes with a bare Adaptall-2 mount that you actually need to attach an adapter for to get a mount. So I’ve got a Pentax mount on it (my main camera now is a Nikon, but I started with Pentax). It’s on my K-50. In truth, I would really highly recommend anyone trying this lens get a mirrorless camera with focus aids and use it on that. While I don’t have much trouble with manual focus, I am sure manual focus on an EVF with peaking would be easier.
But you’re all here for the shots right? How good is this lens? Well, birding is the name of the game, and I believe very few subjects test a lens as well as the fine-feather detail of birds. So bring on the birds!
First, I’ll give you the good news. If you’re really close to the bird (2-3 meters), and you have a stable platform to shoot from like a tripod or your camera bag, this is about the maximum quality you can expect:
This is cropped only slightly. Here’s a 100% crop showing the feather detail:
You can see from the feathers on the left, which is about as good as it gets, the individual feathers are visible. Note that in the actual shot, I applied a little extra sharpening, but in this only the basic import sharpening has been applied. However, the contrast is low and you can already see some degradation of detail. The best 500mm prime lenses will look like you’re actually looking at the feathers in person, and the consumer superzooms will be nearly as good stopped down. This is already a mess. However, because individual feathers are there because we’re so close to the bird, the whole shot looks pretty good, especially if you push sharpening a little. Here is another shot from the same day from a bird that is farther away:
You can see some feather detail here but much as been completely obliterated. Still, with careful post-processing the detail is not bad. I think the funny onion-ring bokeh actually adds to this image. Here is another shot from a longer distance:
It is not too crisp but again, with careful postprocessing it is definitely not bad. Now, the next shot:
It’s taken in harsher light at maybe ten meters, in which bird shots don’t look that great anyway. However, I used this shot to illustrate a 100% crop:
The detail is pretty bad. Even without zooming in I feel a dullness in this shot, but even with an awesome lens it wouldn’t be that great I think. This shot was also handheld without any balance, and I must say that the IBIS of the K50 does not work very well at longer focal lengths. Let’s take a look at another shot:
Okay, this was done supported on my camera bag in a field by the Kew Public Library. It was cropped maybe 40%. There is a lot of obliterated detail here, though the bird was in the shade so the light was not as harsh. I sharpened this image to get some extra detail showing. I would say it’s still a nice image, but not up to modern day standards. Here is the 100% crop:
Again, the extra sharpening of the above is not present in this crop. Quite a lot of obliterated detail, but there is enough to make it look like a photograph at least. Now we come to the final image:
I would say the bird pose here is not perfect because its beak is hidden. However, it’s still rather nice and I do like the bokeh again. I think if you have an image of sufficient sharpness, the onion ring bokeh can be rather charming. This bird was at a similar distance to the Red-rumped Parrot, and it shows. Here’s the 100% crop:
Wow, from here, the detail is not bad. I would say of my many hundreds of shots taken with this lens, this is about the best you could ever expect from it. Certainly below the standards of even the cheap consumer zooms, but still fairly good, especially when given a little extra sharpening.
Of course, these are some of the best images I could get with this lens. Most of them are way worse. In fact, on stationary or slow-moving birds, my keeper rate is astoundingly slow. It only really works on birds that stay put in a given area and you have time to get them. Just forget birds in flight. I’ve occasionally gotten random still birds while hiking decently with this lens. But on average my keeper rate is probably 1/20 or even 1/30. And by keeper I really do just mean sufficiently sharp, not outstanding composition or anything.
So, is this lens suitable for general birding? No. But it’s a fun lens to play around with if you have time to sit in one place for a long time, and experiment. You do get to have bokeh that is quite different than modern lenses so you can create some cool retro images with it. And of course, you will get a much higher keeper rate if you stick to flowers or other still objects where you can really take time to nail that focus and lighting. In fact, the minimum focus distance of this lens is an astounding 1.7m, much closer than modern lenses. At that distance, it can achieve a reproduction ratio of 1:3, so it’s actually great for flowers.