What experience does anyone have in comparing the 135 macro lens to say a 165 with extension tubes? What I am looking for is other than the obvious. Is the 135 a superior lens optically for macro work? I will be using the usual techniques (tripod/mlu/cable release, etc.). I have not purchased either lens, as I am trying to do my homework before getting my 67 system. Is the tube set a better bet than the helicoid tube? I think a combination would be best, but would appreciate any thoughts.

Thanks, Jim K.

-- Jim Korczak (csi-experts@worldnet.att.net), April 28, 1998

Answers

Two pieces of info in case you hadn't seen them already:

1. The helicoid was reviewed here. This will point out some of it's advantages.

and

2. Pentax has a new 100mm macro out. Here is a thread about it.

Cheers and good luck with your Pentax!

-- Benson (btw@vnet.net), April 28, 1998.

I use the 135 macro with the three piece extension tube set, and it has proved optically beyond my macro abilities. This combintation gives me 1:1ish. I believe this will be greater magnification than using the tubes on a non-macro lens. Another advantage of the 135--FOR ME--is that carrying it and a 75 covers the mid focal range and I dont need a 90/105 normal.

ANOTHER QUESTION, has anyone tried using a high-quality diopter on the 135? I was thinking of trying the 62mm Nikon with a 67>62 ring, and was wondering about vingetting? Does anyone make a good 67mm diopter?

-- Mark Alan Wilson (wilson@wildrockies.org), May 05, 1998.

Using a 67-62 stepdown ring with the 135/4 should be OK as long as you step down enough. To determine what is enough, open the shutter on the body and look through the lens. Try to see what the stepdown ring and 62mm closeup rings do to corner vignetting, then step down enough to eliminate any visible vignetting.

(This is based on experience with a 35mm SLR, but should apply to any format. On a 35mm 80-200/2.8 zoom I had to step down to f/8 to eliminate vignetting at 200mm.)

-- Ake Vinberg (avinberg@brio.com), May 05, 1998.

The 135 macro lens alone will only give you a magnification of about 1:3. The tubes with the 135 macro will give you slightly better than 1:1. I don't know about using the tubes with other lenses because I only use them with the 135 macro. However, I believe the instruction book that comes with the tubes gives magnifications for all Pentax lenses with which the tubes can be used. If you don't have access to the book Pentax will send you one for $2.

-- Brian Ellis (beellis@gte.net), September 30, 1998.

I had a similar question to that of the original poster. I compared resolution performance of a 135mm f4 Macro lens at minimum focus distance compared to a 165mm f4 LS lens with a #2 auto extension tube using the same size target area at a slightly greater working distance. The target was an Edmund Scientific resolution target. I used TMax 100 film developed in TMax developer and ran the full aperture series with flash illumination and with the camera mounted on a tripod with mirror lockup and cable shutter release.

Results: Central image resolution was comparable between the two lenses. However, edge resolution was clearly superior with the 135 f4 Macro lens. Other posters have indicated that the 135mm was designed to focus optimally at a close working distance. Because some of the photography I do is of flat autoradiographs, it was worth buying a 135mm f4 macro lens in addition to the 165mm f4 and autoextension tubes. However, I am not sure I could have detected the difference in my regular macro photography of flowers and similar non-planar subjects.

-- William Castleman (Wcastleman@compuserve.com), August 03, 1999.