ProfHankD
Veteran Member
I don't buy many old lenses anymore, but when I do, they're now usually the oddball ones that tend to be somewhat rare and expensive. This is one of those. In fact, it is the most expensive used lens I've bought, costing me the unpleasant total of $371. So, was it worth that?
The lens in question is Spiratone Mirror-Ultratel 500mm f/4. OK, I have to admit that I have an irrational fondness for Spiratone dating back to when I used to frequent their store on Northern Boulevard in Queens, NY. And we're talking about a 500mm f/4. That's two stops faster than your average 500mm... Well, here it is next to my Minolta 500mm f/8 AF Reflex:
I think the size difference between these two 500mm mirror lenses is pretty obvious. The weight difference is just as large. I really appreciate the shiny metal handle on top of the Spiratone; it is the right way to carry the rig.
Both of those lenses are set-up for autofocus on my Sonys. The Minolta lens is on an LA-EA5 which makes it focus with near native performance on my A7RV and A7CR. The Spiratone is mounted on a TechArt LM-EA7 -- I mean the LM-EA7 and my A7CR are mounted on the Spiratone. That's slightly more complex because the Spiratone uses a T mount, and I don't have a T-to-M adapter, so it is actually on a stack of T-to-M42, M42-to-FD, FD-to-M, and LM-EA7. It's also complicated in that the LM-EA7 doesn't have enough movement range to focus the Spiratone, but it can tweak manual focus to be perfect by moving the camera body and also provides lens data (which I had incorrectly set at 300mm when I did my first tests). Of course, the Spiratone is really intended to be manual focus, and I tried it that way too on a T-to-FE adapter.
Unlike most mirror lenses, this Spiratone's manual focus mechanism is in the rear. The focus adjustment is entirely implemented by adjusting the refractive optics at the rear of the lens, and there are two metal rods sticking out from the small focus ring to make it easier to turn. This arrangement sounds odd, but works much better than trying to turn a giant-diameter lens barrel. The only annoyance is that there is also a rotating T mount with a little locking thumbscrew, and sometimes my fingers bump into the thumbscrew when turning the focus ring using the rods. Then again, the rotating T mount means it is easy to rotationally align your camera with the lens on a tripod in either the horizontal or vertical orientation, which is a really nice feature. Close focus is still tens of feet away, but extension tubes or a teleconverter can get you a tighter image.
There is a tripod mount on the lens that balances the weight extremely well. After all, none of the big parts of the lens actually move when focusing, so there is no shift in balance. The tripod mount accepts either standard screw size. I had no problems screwing in a standard arca-compatible mount and using that with a tripod felt pleasantly secure.
Overall, I have to say that this lens is shockingly hand-holdable. Yeah, you'll quickly build your upper body strength carrying it around by the handle, but supporting the lens with your left hand while focusing and shooting with the right is quite effective. With the LM-EA7, I can even set the approximate focus and then just use my right hand to press the shutter button and trigger autofocus -- with the LM-EA7 moving the body a mm or two to tweak focus. As long as I don't ever support the lens by the body or hold the body such that it can't freely move relative to the lens, my A7CR is way below the LM-EA7 motor drive weight limits even though the lens certainly isn't. Then again, only a lunatic would think it OK to support a lens this massive by the body mount.
Enough chat! What do images look like? Well, here are a few quickies shot using it with my A7CR. These are all shot at f/4 and scaled down from 60MP HIF to 1500x1000 JPEGs. Note that the lens comes with a cover that doubles as an f/5.6 Waterhouse Stop, but I didn't try that yet.
Manual focus on the arrow sign, shot through trees
Manual focus on the red leaves
Manual focus on the branches
This one was shot using the LM-EA7 to autofocus on the red leaves, which worked well
Those are very boring shots, but what I see is surprisingly good color, very thin DoF, and more donuts than one should ever really want. ;-) Seriously, it is an out-of-focus look that people tend to either love or hate, and I wouldn't want it in too many photos. That said, the donut bokeh are soft enough that I don't find them as distracting as from some other mirror lenses. Also note that even a little out of focus starts making sizeable donuts.
Finally, I shot a very crude resolution test of a brick wall. Here's a 1500x1000 crop from near the bottom right corner:
Autofocus brick wall shot, 1:1 crop near bottom right corner
It was pretty obvious that the detail was good when precisely focused with the subject in the center, but this brick image shows the lens is still reasonably good near the corners. The catch is that focus is beyond supercritical; there is almost no depth of field, so even slight misalignment of the focus plane with the subject can cause areas to be significantly blurry.
I haven't yet done formal MTF tests (hard to use this with a test chart!). My initial feeling is that contrast is slightly low, but good for a mirror lens. Resolution is not far behind the Minolta 500mm f/8 AF Reflex, which is a very positive statement given I'm talking about hand-held use of a giant lens needing very precise focus. Resolution of this lens isn't really challenging 60MP FF, but I'd say it is better than needed for 24MP FF to look crisp. I would not be surprised if this lens would still deliver enough resolution for 24MP while using it with a 1.4X or 2X teleconverter, and a 700mm f/5.6 or 1000mm f/8 sounds worth trying.
So, was this worth $371? Yes in terms of lens quality. No in terms of how often I'll bother using a lens that is this big and heavy. It is a very special-purpose tool. I have found myself often using the Minolta instead of my excellent Tamron 150-500mm f/5-6.7 native FE lens just because it is easier to carry. This Spiratone is on the wrong side of that usability comparison at almost twice the weight of my Tamron. Anyway, hopefully I'll at least make some nice fall foliage photos with it in the coming weeks... ;-)
The lens in question is Spiratone Mirror-Ultratel 500mm f/4. OK, I have to admit that I have an irrational fondness for Spiratone dating back to when I used to frequent their store on Northern Boulevard in Queens, NY. And we're talking about a 500mm f/4. That's two stops faster than your average 500mm... Well, here it is next to my Minolta 500mm f/8 AF Reflex:
I think the size difference between these two 500mm mirror lenses is pretty obvious. The weight difference is just as large. I really appreciate the shiny metal handle on top of the Spiratone; it is the right way to carry the rig.
Both of those lenses are set-up for autofocus on my Sonys. The Minolta lens is on an LA-EA5 which makes it focus with near native performance on my A7RV and A7CR. The Spiratone is mounted on a TechArt LM-EA7 -- I mean the LM-EA7 and my A7CR are mounted on the Spiratone. That's slightly more complex because the Spiratone uses a T mount, and I don't have a T-to-M adapter, so it is actually on a stack of T-to-M42, M42-to-FD, FD-to-M, and LM-EA7. It's also complicated in that the LM-EA7 doesn't have enough movement range to focus the Spiratone, but it can tweak manual focus to be perfect by moving the camera body and also provides lens data (which I had incorrectly set at 300mm when I did my first tests). Of course, the Spiratone is really intended to be manual focus, and I tried it that way too on a T-to-FE adapter.
Unlike most mirror lenses, this Spiratone's manual focus mechanism is in the rear. The focus adjustment is entirely implemented by adjusting the refractive optics at the rear of the lens, and there are two metal rods sticking out from the small focus ring to make it easier to turn. This arrangement sounds odd, but works much better than trying to turn a giant-diameter lens barrel. The only annoyance is that there is also a rotating T mount with a little locking thumbscrew, and sometimes my fingers bump into the thumbscrew when turning the focus ring using the rods. Then again, the rotating T mount means it is easy to rotationally align your camera with the lens on a tripod in either the horizontal or vertical orientation, which is a really nice feature. Close focus is still tens of feet away, but extension tubes or a teleconverter can get you a tighter image.
There is a tripod mount on the lens that balances the weight extremely well. After all, none of the big parts of the lens actually move when focusing, so there is no shift in balance. The tripod mount accepts either standard screw size. I had no problems screwing in a standard arca-compatible mount and using that with a tripod felt pleasantly secure.
Overall, I have to say that this lens is shockingly hand-holdable. Yeah, you'll quickly build your upper body strength carrying it around by the handle, but supporting the lens with your left hand while focusing and shooting with the right is quite effective. With the LM-EA7, I can even set the approximate focus and then just use my right hand to press the shutter button and trigger autofocus -- with the LM-EA7 moving the body a mm or two to tweak focus. As long as I don't ever support the lens by the body or hold the body such that it can't freely move relative to the lens, my A7CR is way below the LM-EA7 motor drive weight limits even though the lens certainly isn't. Then again, only a lunatic would think it OK to support a lens this massive by the body mount.
Enough chat! What do images look like? Well, here are a few quickies shot using it with my A7CR. These are all shot at f/4 and scaled down from 60MP HIF to 1500x1000 JPEGs. Note that the lens comes with a cover that doubles as an f/5.6 Waterhouse Stop, but I didn't try that yet.
Manual focus on the arrow sign, shot through trees
Manual focus on the red leaves
Manual focus on the branches
This one was shot using the LM-EA7 to autofocus on the red leaves, which worked well
Those are very boring shots, but what I see is surprisingly good color, very thin DoF, and more donuts than one should ever really want. ;-) Seriously, it is an out-of-focus look that people tend to either love or hate, and I wouldn't want it in too many photos. That said, the donut bokeh are soft enough that I don't find them as distracting as from some other mirror lenses. Also note that even a little out of focus starts making sizeable donuts.
Finally, I shot a very crude resolution test of a brick wall. Here's a 1500x1000 crop from near the bottom right corner:
Autofocus brick wall shot, 1:1 crop near bottom right corner
It was pretty obvious that the detail was good when precisely focused with the subject in the center, but this brick image shows the lens is still reasonably good near the corners. The catch is that focus is beyond supercritical; there is almost no depth of field, so even slight misalignment of the focus plane with the subject can cause areas to be significantly blurry.
I haven't yet done formal MTF tests (hard to use this with a test chart!). My initial feeling is that contrast is slightly low, but good for a mirror lens. Resolution is not far behind the Minolta 500mm f/8 AF Reflex, which is a very positive statement given I'm talking about hand-held use of a giant lens needing very precise focus. Resolution of this lens isn't really challenging 60MP FF, but I'd say it is better than needed for 24MP FF to look crisp. I would not be surprised if this lens would still deliver enough resolution for 24MP while using it with a 1.4X or 2X teleconverter, and a 700mm f/5.6 or 1000mm f/8 sounds worth trying.
So, was this worth $371? Yes in terms of lens quality. No in terms of how often I'll bother using a lens that is this big and heavy. It is a very special-purpose tool. I have found myself often using the Minolta instead of my excellent Tamron 150-500mm f/5-6.7 native FE lens just because it is easier to carry. This Spiratone is on the wrong side of that usability comparison at almost twice the weight of my Tamron. Anyway, hopefully I'll at least make some nice fall foliage photos with it in the coming weeks... ;-)
