Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-29-2008, 02:45 PM   #1
Forum Member
houstonmacgregor's Avatar

Join Date: May 2008
Location: Houston, TX
Posts: 97
Mirror lenses

To those who have helped me on other threads, thanks. Ended up with the16-45 and the 55-300.

Recently diagnosed with LBA ,I have a question. What are and how good are mirror lenses, ie 500 f8

Thanks

07-29-2008, 03:13 PM   #2
Inactive Account




Join Date: Jul 2008
Location: Nottingham UK
Posts: 9
They use a pair of mirrors, facing each other which fold the light back and forth and magnify it, in a similar way to a telescope. There are a couple of issues, they are all fixed aperture, usually f/8, and one of the mirrors is necessarily mounted in the front element. When its focused on a subject, this doesn't matter as the mirrors focus the light in such a way as to make a complete image, however, if out of focus the secondary mirror gets in the way creating a dark round shadow in the middle. This is what causes the characteristic doughnut shaped out of focus highlights.

The upside is you can get silly focal lengths in a much smaller and lighter package and for a fraction of the price of a conventianal prime or zoom.

I've got a Sigma 600mm f/8 and its pretty good. When I was thinking of buying it I did some research and a few said it was the best mirror lens out there. I can't verify that as its the only one I've ever used.

There's a dedicated flickr group which might be worth a look

Flickr: Mirror Reflex Lens
07-29-2008, 06:37 PM   #3
Site Supporter
SpecialK's Avatar

Join Date: Dec 2006
Location: So California
Photos: Gallery
Posts: 14,428
QuoteQuote:
...This is what causes the characteristic doughnut shaped out of focus highlights.

The upside is you can get silly focal lengths in a much smaller and lighter package and for a fraction of the price of a conventianal prime or zoom.

I've got a Sigma 600mm f/8 and its pretty good. When I was thinking of buying it I did some research and a few said it was the best mirror lens out there. I can't verify that as its the only one I've ever used.

There's a dedicated flickr group which might be worth a look
I had a Sigma 600 in my film days and thought it was good enough to wish I could find one for my K100D.

I recently tried (and returned) a cheap Phoenix/Samyang 500 which I could not get to focus on my subject, with or without focus confirmation. I was not too surprised, though.
07-29-2008, 07:16 PM   #4
Pentaxian
Wheatfield's Avatar

Join Date: Apr 2008
Location: The wheatfields of Canada
Posts: 10,043
QuoteOriginally posted by houstonmacgregor Quote
To those who have helped me on other threads, thanks. Ended up with the16-45 and the 55-300.

Recently diagnosed with LBA ,I have a question. What are and how good are mirror lenses, ie 500 f8

Thanks
The only mirror I'd consider buying is the Tamron 500/8. It's one of only two offbrand lenses that I own.
It has the typical yukky donut bokeh common to mirrors, but it is a remarkably sharp and contrasty lens.
Below is a handheld shot done with the K10 and 500mm Tamron, the other picture is a 100% crop,
Note, it would look better if I had used a tripod......


Last edited by Wheatfield; 02-05-2011 at 08:44 PM.
07-29-2008, 08:42 PM   #5
Pentaxian
ivoire's Avatar

Join Date: Mar 2007
Location: chicago burbs
Photos: Gallery
Posts: 3,356
I have a tokina 500mm f8 and a sigma 600mm f8. both have good optics. Mirror lenses are inexpensive and can produce very nice images. they do have quirks and limitations that will require getting accustomed to. I can recommend both of these lenses and the tamron 500mm f8 is highly regarded, even mor so that the tokina and sigma. heres a thread posted previously. there are many more:

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/27457-tokina-f8-mirror-lens.html

Mirror lens info:

http://mirrorlens.blogspot.com/

http://photo.net/learn/optics/mirrors/index.html

I have several pics with these lenses here:

Art by Michael Wolf - RedBubble

Last edited by ivoire; 07-29-2008 at 09:28 PM.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
k-mount, lenses, mirror, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mirror Lenses....good or junk? Raptorman Pentax SLR Lens Discussion 12 01-25-2010 04:00 PM
New Vivitar Series 1 Mirror Lenses jfsavage Pentax SLR Lens Discussion 1 04-01-2009 09:36 AM
Mirror Lenses... Powermarc Pentax SLR Lens Discussion 61 01-05-2009 03:48 PM
Sigma mirror lenses jeepinandcamping Pentax SLR Lens Discussion 7 01-26-2008 02:37 AM
Mirror Lenses Buddha Jones Pentax SLR Lens Discussion 10 05-12-2007 12:15 AM



All times are GMT -7. The time now is 10:01 AM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top