[PenPen]

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Rokinon 500mm f/ 8.0 NIB. For my k2000. I have a quality tripod. Aluminum body,T-mount included,warranty.
Please don't hesitate to tell me I'm an idiot and have no idea what I'm doing.I can take it.Seriously.I need all the help I can get in purchase matters!!
Thank you to all who answer.
Annie PenPen

[jatrax]

Cannot tell much from your description, you need to either provide the link or the complete information. From what you said it could be one of the 'bazooka' 500mm lenses that are common and cheap or a 500mm mirror lens which is also common and cheap. There are some of the mirror lenses that have rather good image quality, though the bokeh is a little strange. These are usually faster than f/8 though.

What is the asking price? Good is a relative term. What are your requirements for image quality? A 'good' 500mm for someone taking bird photos for publication might cost several thousand dollars. Or tens of thousands if you are talking Canikon fast glass.

[Adam]

Generally speaking, no, those generic mirror lenses aren't too hot unless you're shooting stuff that isn't moving and are using a tripod.

Reviews (found via forum search):
https://www.pentaxforums.com/userreviews/rokinon-kenko-bower-samyang-500mm-f-6-3-dx.html

[slackercruster]

Mirror lenses are tough to get high IQ out of. They are OK if your not too demanding. Compact, cheap and light. Here is a shot taken with a Sigma 400mm film era mirror.



...Don't know about your lens in question though.

[PenPen]

Generally speaking, no, those generic mirror lenses aren't too hot unless you're shooting stuff that isn't moving and are using a tripod.

Reviews (found via forum search):
Rokinon / Kenko / Bower / Samyang 500mm F/6.3 DX Lens Reviews - Miscellaneous Lenses - Pentax Lens Review Database

It's a loooong lens,reminiscent of my beloved Stellarvue refractor telescope.Not as big,of course,but it definitely is not a reflector shortie!
It's f/8.0 ,Manual,aluminum,warrantied and NIB.

[Canada_Rockies]

Ah, you have what used to be called a "girl watcher special" in the days when political correctness was not in fashion. They are not, technically, telephoto lenses but long focus lenses. A telephoto lens is shorter than its focal length. They can work, but they are slow. On a DLSR you will be working in the middle of the lens, so the edge problems won't be too bad. The image quality won't be all that good, but you might like it.

[PenPen]

Thank you for your help,and all others who answered as well. I'm not sure what I will do,but I will continue to pore over the message boards here and learn a lot!!!

[CTR01]

From my profile page:

Don't buy list:
Opteka 500mm f/8 mirror lens,2x TC, and
t-mount adapter from eBay...tried 2, both failed.


bought it from 47th st photo via ebay, both had the t-mount adapter get suck on the lens...
the image quality is not good even when using a tripod (Manfrotto 055XPROB tripod and Manfrotto 494RC2 tripod head) and IR remote and shake reduction off...
but maybe your lens will turn out to be a goodie/keeper?

[PenPen]

...without checking in here first.Already you nice folks have helped me a lot, and saved me money!!!
.There is an abundance of info here,and experienced photogs to help to keep me informed for a long,long time.
Thank you again.
Annie

[WPRESTO]

As with other comments made here, I'd advise against this lens. There are cheap 500mm lenses of both mirror and, as noted by CANADA_ROCKIES, of long-focus variety. It is VERY difficult to get good image quality in a long focal length lens of any design. If you're looking for a bargain telephoto, try EBAY for the old 400 f6.3 Spiratone. It used a T mount so you should be able to purchase one with a Canikon mount and switch to a K mount. It isn't a great lens, but it is much better than its price would suggest (around $100 in good condition). A local friend who is an outstanding nature photographer owns one that he still sometimes uses. It's an odd lens - the entire barrel rotates for focusing. Another lens you might find at higher price is the 300 f6.3 Takumar. It's another lens better than its price would indicate, but you'll pay more than for the Spiratone. There was a preset screw mount version which was limited by a rather long close-focus distance. However, it works very well with a Canon achromatic close-up lens to get to the distance needed for songbird photography.

[WPRESTO]

I just checked at KEH. They have a couple K-mount 300 f4 Takumars for under $200. They are in "bgn" condition = bargain, which means they will look well-used. If you can put up with the scruffiness of the barrels, this is a decent lens (NOT up to the quality of a modern ED tele).

[WPRESTO]

Dear PenPen:

Not knowing you budget, it's hard to offer realistic suggestions. However, there is a SMCA 400f56 currently being offered in the Forum marketplace for a reasonable price. There are multiple copies of this lens up for sale on EBAY with prices ranging from around $800 for one in mint condition down below $500 for a well-used lens. This is a very good lens, MUCH better than the Rokinon both optically and mechanically. Actually, in terms of fit-and-finish, it exudes quality (I have one).

[GibbyTheMole]

If you're on a budget, I'd look for a Tair 3M-5CA or Tamron f:8 500mm mirror lens. Both will get you the reach you need with good image quality. I have the Tair & it's definitely a keeper. The Tair's very slightly better than the Tamron, but they're very close.

KEH has several Tamrons in the $150-$180 range. There's a Tair on eBay here.

Any other mirror lens is a waste of time & money, IMO.

A nice thing about a mirror lens: no purple fringing.

Good luck!
Bobbo :-)

[reeftool]

I have an Opteka 500/8 which from what I understand reading up on it, it is the same lens as the Rokinon with a different label. I bought it for one reason and that was to get shots of my daughters crew team in college for a couple of courses they competed on that were a good 400 meters out on the water at the closest. It did the job but I can honestly say that my crops from my 70-300 Sigma were better IQ. It's very light to carry but it still needs to be on a tripod. 500mm is a lot and holding it steady is difficult at best and nearly impossible for me. The f/6.3 versions seem to be a little better judging from the posted shots and the Tamron 500mm mirrors are excellent if you can find a used one. I haven't used the lens since my daughter graduated in 2010. This is one of my shots with the Opteka from a couple of years ago at the NY State Collegiate Rowing Championships.