500mm Mirror lens - Any comments on it's usefulness?
I know these have been mentioned on the site before but I think it was a while ago. So just to refresh my aging memory would someone like to comment on the suitability/usefulness of the 500mm Mirror lens like this one on ebay.
Not that I'm really looking to buy one, really, but if the price is right
it's similar to a prime focus telescope, apparently they give really weird looking bokeh, and in daylight, weird donut shaped light rings and whatnot...
i would do some research on teh wide world of the internets, then make a judgement....
if you do end up getting it, i owuld be most interested to see your results!!!!
Oh I'm not really serious about it, I'd rather use the ED80, though I'm sure someone sometime will be, which is why I was fairly specific in the thread title.
At f8 (500mm/100mm = f5 so that obstruction is pretty significant) though it might be ok for luna imaging without having to carry a telescope around. Or maybe you could adapt a visual back for it and create a cheap 500mm mak? Just ideas.
I have a Tokina 500mm F8 and it produces photos that are a little soft. It really requires the use of a tripod to minimise camera shake. These lenses are quite compact and lightweight; often fooling the unsuspecting photographer into thinking they can hand hold it!
I’ve had mine for over 15 years and only used it on a handful of occasions with average results.
Do you think the softness is from poor focusing mechanisms, poor mirror or because of the large CO? What's the contrast like with it Dennis? Normally that would be one thing I thought the CO would have caused problems with.
Do you think the softness is from poor focusing mechanisms, poor mirror or because of the large CO? What's the contrast like with it Dennis? Normally that would be one thing I thought the CO would have caused problems with.
Hi Paul
I have used the lens on a substantial tripod, using a cable release, at shutter speeds of 1/1000 sec in an attempt to constrain those factors, but the overall image still looks a little soft compared to my normal lenses, or the WO 80mm ED II Apo that I have.
Paul, I've been playing with an MTO 10.5/1100 mirror lens, and probably agree with Dennis that images end up a little soft. I used the lens for all my eclipse shots - lovely scale! My tripod is way too light & ricketty, and anything involving any longer exposure ends up fuzzy (eg totality!). Suspect this is not only movement through the field, but vibration from shutter opening as well. It is the same as shooting through a small scope, but control of focus is much more tricky. In fact you can buy (or make) visual backs to convert the lenses into scopes! Adds a fair bit of weight if you want to piggyback too.
That having been said, it's a lot of fun, with good terrestrial applications too. Anyone got a good heavy tripod?
I wonder how these things go for mirror flop? Also notice the rear thread is only 30.5mm, less than 1.25". Wonder that the thread is and how much vignetting would occur?
Dennis? Rob?
I'm really liking the idea of a guidescope. If it worked then $200 for a guidescope wouldn't be too bad, really.