Mirror lens

[mattmo]

Have been given a 1000mm mirror lens for nowt

whats the general opinion of these lenses? i havnt had a chance to use it yet

thanks

matt

 

[bindex]

Interesting to play about with Matt. But in general terms, fixed aperture is usually pretty slow, usually fairly crap IQ too. But very light for the focal length of course. Not something I'd ever recommend anyone to buy nowadays... but you got it at the right price!

Have fun with it.

cheers

 

[mattmo]

i think i will cheers!

 

[Anorakus]

Mirror lenses always used to be regarded as a viable cheaper/lighter alternative to conventional telephoto lenses in the days of film SLRs - maybe digital SLRs show up their limitations.

They have fixed apertures, usually something like f/8, but this wouldn't be as much of a problem with the ability to select an ISO on a digital SLR.

They also give very distinctive out-of-focus "doughnut" highlights due to the lens construction, viz.

A.

 

[mattmo]

cheers A

Im gonna have aplay with it tonight

matt

 

[andyred]

Father-in-law has a mirror lens for his Minolta and gets some good results with it, the 2 main things to remember are the focus point is critical with a mirror lens and probably a tripod is a definate due to shake. Hope you have some fun with it

 

[jgs001]

My Skymax 102 telescope is of the same design (Maksutov Cassegrain) and it works very well for targets like the moon. One thing to watch for is Collimation, alignment of the mirrors, if they are not accurate then the image will be degraded. Knocks will put the collimation out. I've not seen a mirror lens, so it may be that the rear mirror element is fixed which may remove this potential issue.