So, I've been on a big selling binge lately, and it continues, but my Buy-It-Now finger got itchy the other day and I have a new condition Asahi-Pentax 50mm f4 Macro-Takumar (preset) on the way. As far as I know, this is the only classic 50mm macro lens that does 1:1 macro without any attachments. I've also discovered that it was tested at one point to resolve 81 lp/mm at f8. Not too shabby for a 4 element design (could we call this a "Macro-Tessar"?)
SteveFE over at forum.manualfocus.org really loves his copy and has posted some really nice samples. In anticipation of the arrival of this lens, does anyone out there have any experience with it? Samples? Opinions?
optically it is fantastic like any other macro lense. Super sharp. I can't recall if my copy did 1:1.
I can't find any samples at the moment, but it was sharp.
Oh, focusing was very smooth
Looks nice! Simple is good sometimes. Look at some of the more reknown rangefinder lenses... simple symmetrical designs sometimes yield the best results. This tak looks like a near-symmetrical modified gauss design. There's a lot of great macros that are similar though usually at least 5 elements.
Well, I picked it up this morning and it is already screwed up. The focus ring was a bit "odd" when I first started using it. It then got stuck completely and I had to mess around with it to get it unstuck. Then all of a sudden it became very, very smooth (Takumar smooth) but it won't focus any further than 2 feet. I feel ripped off. Other than that, it is in "brand spanking new" condition. Odd. Very odd.
If it won't focus any further than 2 feet it means that the "center lens assembly" is not moving close enough toward the back of the lens.
I realize that you already know that part but I suggest that you check that the "finger(s) or prongs" that prevent the center lens assembly from rotating as the focus ring is turned are engaging in the corresponding slots in the assembly. If they do not engage with these slots they act as stops preventing further movement of the assembly toward the back of the lens. Normally the focus ring prevents disengagement of these prongs as its own stops fall inside the limits of travel of the center lens assembly.
The lens may have previously been reassembled incorrectly or perhaps the retaining screws for the prongs have backed off. You may be able to get things working again by removing the retaining screws and pulling out the prongs. Rotate the focus ring toward infinity until the entire center lens assembly rotates one full turn and the slots are back in position to receive the prongs. Reinstall the prongs and you should be able to focus to infinity or at least close to infinity. If you are lucky you will get infinity, if not, it simply means that a bit more adjustment will be required elsewhere.
If you don't get (but get closer to) infinity and the prongs keep disengaging when focusing to MFD it is because the center lens assembly field of movement is shifted too far forward. This shortens MFD but prevents reaching infinity focus and results in the disengagement I describe. I think I can help you correct this possible outcome as well.
Thanks for the advice Nick. After I posted that last message, I decided I had nothing to lose and I took the lens apart. I'm happy to say I figured it all out!
It is all back together and I get full focus travel and it is super-smooth, as it should be. It was much easier to fix than I thought it would be.
In good light this lens lives on 5D1 for walkaround the forest; wide range of subjects from from landscapes to 1:1 macro, excellent IQ from wide open. Can't locate right now a particular photo that caught my attention -- so there I was walking through the woods without other lenses, see a deer in the distance through the brush (infinity), wishing I had the 200mm I figured what the heck and snapped it anyway -- the deer is so unbelievably sharp in that photo even at 100% actual pixels! (still looking for that photo -- now the rains have arrived I'll be spending more time inside with the computer and a warm fire in the woodstove...)
I'm interested in cogitech experiences with this lens; very surprised it is "new" there, and considering the past I predict it will be a surprise favorite!
I tried a bunch of stuff with it last night; stars, street lights, indoor stuff, added an m42 2x tele-converter, etc. Will post results when I return home (away for the weekend).
(could we call this a "Macro-Tessar"?)
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