Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
10-15-2008, 03:40 PM   #16
Loyal Site Supporter

Join Date: Dec 2006
Location: Frazier Park, CA
Photos: Gallery
Posts: 835
I've been playing with a home-made extension tube and a Viv 105 macro lens. DOF is tiny, flash a must and it took me a while to figure out the flash. My extension tube started out in life as a K-mount 2X TC so it doesn't have contacts, making my lens a manual lens. Not a problem - I used a 540 flash set to A mode. The only thing that I had trouble with is figuring out that I lose a bunch of light due to the extension tube, so needed to use something around f16 while the flash was set to f22, or else use a higher ISO (those types of things don't come naturally to me).

I've been thinking of trying to reverse a 50mm 1.7 lens in front of the macro lens. Does the DOF become as minimal as it does with extension tubes (I don't have a geared focusing rail)? Would it be any easier to deal with, or would it be so heavy a combination it would be practically impossible to use? Since wider lenses give more magnification, would it make any sense to try using a 24mm lens? I think my 24mm lens is the same 52 threads as the macro lens, while the 50mm is 49 and I would be stepping down. I might be able to spring for a male to male ring, but know a Raynox is beyond my means at the moment.

10-15-2008, 03:49 PM   #17
Loyal Site Supporter
Canada_Rockies's Avatar

Join Date: Nov 2007
Location: Sparwood, BC, Canada
Photos: Gallery | Albums
Posts: 9,534
I have found that the depth of field is basically based on the amount of magnification of the image. More magnification = less depth of field. It will be extremely difficult to see through the assembly. The more extension, the more light is lost. It's a lot of fun, though!
10-15-2008, 04:57 PM   #18
Veteran Member
m8o's Avatar

Join Date: Jul 2007
Location: 40-55'-44" N / 73-24'-07" W [on LI]
Photos: Gallery | Albums
Posts: 3,102
Richard, here's a great thread from a while back... note post #9: (screw needing/having that Canon body mentioned earlier )

  • 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!
focus, k-mount, macro, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: Pentax primes (F50/1.7, F50/2.8 macro, F100/2.8 macro, FA100/2.8 macro) dgaies Sold Items 5 11-02-2010 11:51 AM
For Sale - Sold: PENTAX-D FA 50mm F2.8 Macro and Sigma 180mm F/3.5 EX DG IF APO Macro Lens LenWick Sold Items 9 06-16-2010 11:09 AM
For Sale - Sold: Sigma DL Macro Super 70-300mm f/4-5.6 1:2 Macro Lens, Worldwide Ship! wallyb Sold Items 10 12-16-2009 10:36 PM

All times are GMT -7. The time now is 06:31 PM. | See also:, 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?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]