mirror lenses Centon 500 - f8???

I've noticed these can be had quite cheaply, are mirror lenses any good? will this Centor work on my K10?
I remember my dad telling me about them but I haven't heard anything since.
If I remember correctly they are good for moon shots (or similar) but have a strange bokeh.

Generally the cheaper ones are dreadful. They are also easily damaged, so second hand ones may be even more dreadful.

The Tamron has a good reputation, but I was not impressed with the one I tried.

Their main advantages are small size and low weight for a long focal length. I have the Centon, and it's "ok". Someone around here posted some shots recently, which were taken with (i think) the tamron and they were far better than I get with the centon.

Well sounds like they are er...inexpensive for a reason.
but might be worth having fun with tho'.
I'm up to 300mm at the mo', do you think the Centor would be sharper than my Tamron with a converter? or able to do something interesting?

there was a 500mm f5.6 mirror lens out there . pretty cheap....I wonder how well that would autofocus with the af 1.7 teleconverter....that would be like a 1300mm f10 telescope (roughly).

The Centon mirror lenses get mixed reviews, mostly unfavourable. If you really must try a 500mm mirror (or reflex) lens, at least try a decent'ish one. The Tamron BBAR 500mm f8 lens I had was a reasonable performer and is about as good as they get. I sold it only because I just wasn't using it. Pentax once made a 400-600mm reflex zoom but I haven't a clue how good or bad it is/was.

OK guys I'm trawling the internet and I've come across a Paragon 300-600 mirror. any ideas if this is better or worse than the Centor? I am just going to be messin' around, but I might as well get a half decent 'telescope'.

Here's the thread with the Tamron 500mm mirror examples

https://www.pentaxuser.com/forum/viewtopic.php?t=5767

courtesy of Gartmore

Anything with 'Centon' on is usually sh*t........

The best mirror lenses are the Russian (actually Ukrainian) 'Rubinar' lenses in 300mm f8 and f5.6, 500mm f8 and f5.6 models and also 1000 mm models. these lenses are available in various harware configs including military quality and macro versions at amazingly low prices. Optical quality is good and those rebuilt by Hartblei in Czech Rep. are excellent.

Older good mirrors were made by East German Zeiss for pentacon camera,..the 1000mm was military quality and used on the wall for looking at the west and also by Bunderswehr for looking at the East,...but, you need a trolley to move it around.....

You may also find marque mirror lenses of very nigh quality, even higher prices and so rare that you might not find them at all...

Pentax made 400-600mm zoom, 1000mm and 2000mm mirror lenses. The 2000mm weighed 8kg so it won't be in my camera bag.

I've got the Tokina 500mm F8 and found it quite decent - it's also usually fairly cheap 2nd hand. There are some example shots in this gallery http://www.pbase.com/niblue/mirror

I think I will hang around for one of the better ones, I like the images by niblue, mirrors clearly have some interesting applications. Think I'll need a stronger tripod tho'..

Is there such a thing as a Paragon 300-600 or did my seller mean pentacon? (I hope)

I got rid of my Centon 500 F8 after I did a side by side comparison with my K10D. Centon 500 F8 vs Pentax FA 80-320 at 320 and cropped, the 80-320 won hands down. I would expect you'd get the same result if you compared it to your Tamron 70-300.

Tamrons come uo all the time on eBay. I'm watching one at the moment.
I bought one last month for £62 inc. P&P and I like it 'cos its so much lighter and easier to handle than traditional lenses. There are downsides;
Fixed aperture at f8
Shallow depth of field
Bokeh produces strange donut shapes in some shots
Some people think they lack contrast

On the upside, they focus close at 1.7mtrs.

Tamron did a 350mm mirror lens as well and one of those is on eBay at the moment for spares or repair. Could be no good but I might take a punt if it goes for less than about £15.

I was given one of these and had to pay out £10 for a T-Mount. So far that £10 has been wasted as the lens is very poor - it focuses way beyond infinity and is therefore difficult to use on anything as close to you as the moon. At least I now have a T-Mount just in case one day I might need it!