[Oldseabee]

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Just run across this mirror lens. You would have to get an adapter to mount it on a Pentax camera and that could be a deal breaker. You might also have to hire a pack animal to carry it. Jim
*Rare* Nikon Reflex-Nikkor 2000mm f/11 Mirror lens w/ Aluminum case 2000/11 | eBay

[grahame]

it is only 40 lb. With or without a camera does not make much difference . a tripod is also a piece of cake comparing to your lens, which might make things a little easier. you can do that!

[deus ursus]

Well, you don't need to go to other brands to get a lens like that: SMC Pentax Reflex 2000mm F13.5 Reviews - K Prime Lenses - Pentax Lens Reviews & Lens Database

[ismaelg]

I'll wait for the f2.8 version...
The lens cap should be about 3ft wide

[disconnekt]

I'll wait for the f2.8 version...
The lens cap should be about 3ft wide

Im too cheap to get the original lens cap, will use round metal trash can instead lol

[AstroDave]

I think I'll buy a new car instead (or two!).

[MossyRocks]

At those lengths I have often wondered if just getting a telescope would be a better solution.

[BigMackCam]

At those lengths I have often wondered if just getting a telescope would be a better solution.

That's exactly what this is - a catadioptric telescope with an F-mount.

I have a Soviet MTO 1000mm catadioptric lens, and there was an astronomy kit sold for these that included an eyepiece adapter and various eyepieces...

[WPRESTO]

Several comments:
1) For about a year I had a Pentax 1000mm f11 mirror lens. Despite multiple efforts, I failed to get one keeper image. I suspected camera motion, a major problem with a long lens. so I mounted it on a massive wooden tripod, put in high-speed slide film (ISO 400 in those days) and took it out on a cloudless sunny day and tried to get a picture of a green heron that was out in the open on a pond. No luck. IQ unacceptable.
2) I have read through multiple reviews of mirror lenses and here is the general opinion:
A) The Zeiss 500mm f8 mirotar is the best mirror lens - - fit, finish and IQ
B) The bargain mirror lenses, if you want to experiment, are Tamron's adaptall and early versions of the Russian MTO. These generally are second-tier for IQ and MUCH less expensive than the Mirotar
C) Nikon's 500mm mirror has most of the faults of most remaining mirror lenses which are: a) IQ not quite as good; b) "hot" center, which perhaps indicates vignetting but in-camera meters tend to expose for the edges so unless you compensate, images looks excessive bight in the middle rather than too dark at the edges.

I have never seen a formal review of any 2000mm reflex, nor a test of the equally massive Zeiss 500mm f4.5 Mirotar that was made for the Contarex (how many of those lenses were made?). I think these fall into the category of purchase if you want, experiment and post the best you can get, put it on a shelf because these are primarily collector's items.

[MossyRocks]

That's exactly what this is - a catadioptric telescope with an F-mount.

But a good Newtonian telescope at 2000mm costs a lot less than that lens which is why I was wondering if going the telescope route would be better. There are some very good reflectors that don't carry the Nikon name and thus aren't $32,000. It looks like for about $8,000 you can get a 2000mm f/3.9 scope with goto mount which would seem to be money better spent.

I have a Soviet MTO 1000mm catadioptric lens

I also have in my possession this lens as it is on semi permanent loan from a friend who go in trouble with his wife and needed for it to live somewhere else. It is M39 mount and to get the clearance from the popup flash I have to stick a teleconverter in the mix so I use it at 2000mm and f/20. It is big, fun, and of limited use

[Ontarian50]

From what I can tell, most of the mirror lenses beyond the 500 or 600mm range were really marketed to the "industrial/government" users.

There wasn't much you really needed to photograph from such a distance, aside from rocket launches, or keeping an eye on ships violating territorial waters.

All the disappointments with the mirror lens compromises were of no consequence to those who just had to get some sort of decent image at a distance. Not many were made, prices were high, and customers were often government departments.

But yes, you can get similar results by attaching your camera to one of the newer catadioptric telescopes. But again, it's hard to get sharp images, and they still fall short of the standards most photographers hold for pictorial images.

[SteveinSLC]

You can get an 11" Celestron Edge HD that's 2800mm F10 for $3200 or 1/10 the price of that Nikon. Given the more modern optics on the Celestron, it might be better too. And if you're wanting to do astro, you could get a very nice Astro-Physics mount, and still come in well under the price of that Nikon.

For terrestrial photography, there's not a lot of point...once you start talking about objects so far away that a big SCT like that would be helpful, atmospheric haze, wind and heat distortion start to degrade picture quality.

[MossyRocks]

atmospheric haze, wind and heat distortion start to degrade picture quality.

Even at the long focus end of a 200mm lens those become a problem. I have a number of pictures from a recent trip where when zoomed in at 1:1 there are lots of wavy lines that should otherwise be straight that were taken with a 200mm.

[WPRESTO]

As best I can tell. astronomical telescopes, either mirror or refractor, usually have substantial field curvature that is troublesome at typical photographic distances. a "field flattener" can correct this to some extent, but they are designed for use at infinity. Apochromatic retractors made for astronomy, having very simple optical systems by photographic standards (commonly a doublet or triplet design, either air-spaced or cemented) commonly have excellent to outstanding central IQ. I have seen excellent bird images taken with such optics, but they are expensive, very large, and not at all easy to use.

[disconnekt]

Several comments:
C) Nikon's 500mm mirror has most of the faults of most remaining mirror lenses which are: a) IQ not quite as good; b) "hot" center, which perhaps indicates vignetting but in-camera meters tend to expose for the edges so unless you compensate, images looks excessive bight in the middle rather than too dark at the edges.

I have never seen a formal review of any 2000mm reflex, nor a test of the equally massive Zeiss 500mm f4.5 Mirotar that was made for the Contarex (how many of those lenses were made?). I think these fall into the category of purchase if you want, experiment and post the best you can get, put it on a shelf because these are primarily collector's items.

Speaking of a Nikon Mirror lens, stumbled upon this while browesing on ShopEvilWill, a 500mm f8 Reflex: Nikon 500mm f/8 Reflex-NIKKOR-C w Case - shopgoodwill.com