[mikeSF]

man, that 50 1.4 looks pretty bad in these comparisons, especially at f/4 where it should already be very sharp - dont you think the TC has a significant effect on IQ? That's an additional variable of course. i know you are doing this for fun and not science, but still.
That said, i just ordered the SMC Tak 105 based on some of the wonderful shots i've seen posted in the forums.
The Soligor certainly looks interesting.
thanks for posting.

[StevenVH]

If you still have these cameras, I have both a Miranda and Nikon T-4 adapter I can send you. It always seems like the interesting lenses come with non-Pentax T-4 and TX adapters.

I have tried "focus-bracketing" on my latest test. I focus as best I can, then take a series of shots after moving the focus ring back and forth in small increments. It can identify focus errors and maybe help if the lens has a curved field. Subject choice is very important too. The right subject can emphasize focus errors. I also like to have something detailed in the corners to look at.

Testing is tedious, even for simple sharpness, and it's difficult to rule out all potential errors. I think each test is useful and adds to the body of knowledge, even if it's not definitive.

Thanks, but the Miranda and Soligors are long gone. I do still have a couple of moldy Nikons, but their only use is as bookends these days.

I still don't like my results with or trust AF for critical focusing and I find I'm habitually tweaking the focus anyway. With my growing collection of A lenses I don't have a choice of course. I'm definitely finding it difficult to get what I want with the K200D. I find the viewfinder dim and the focus screen vague at best. I've got the eyepiece loupe and am waiting on a split-image screen, but expect to upgrade to a K20 soon.
I've been practicing with focus bracketing with the intent of just incorporating the method into my habits. In the film days I would bracket exposure and focus when the situation allowed, but it's only been lately that I've felt the need to be that critical again.
Agreed, subject as well as many other factors effect the importance of focus accuracy and lens characteristics. When the situation allows I too search the composition for a reference point.
I don't think any field test can really be definitive and even a lab test really only applies to that particular sample. The process though is very valuable if only to increase familiarity with ones equipment.

Okay, need to stop dreaming about my next lens now and do some work.

cheers

[stevebrot]

I do see the problem with the green light. OTH with my eyes and glasses and the tiny little hole they expect us to look at these days... OY! Seems like I have to take each series with slightly different focus for each lens and then pick the best one.

Yep, the green light is only as accurate as the AF system

I thought you had a split-image screen. I have been doing some tests on my manual focus teles and would be lost without the split-image/micro-prism. Even with the split image I take two or three shots for each lens/aperture combination and refocus for each shot. I then take the best of two/three for the actual between lens comparison.

Steve

[Nesster]

Thanks everyone - I debated posting these due to the issues, but I'm glad I did as there's a lot of good info out of the discussion.

man, that 50 1.4 looks pretty bad in these comparisons, especially at f/4 where it should already be very sharp - dont you think the TC has a significant effect on IQ?

Yes, that was the point, I just figured 2x 1.4 = 2.8 and the focal length is about the same... Let's see what shows up.

The test points out two things - 1) even a bit of yellowing affects color balance, even with AWB on and 2) nice light bloom and vintage optical quality can be achieved via the addition of a cheap tele converter.

[georgweb]

Thanks for the effort Nesster,

and accidentally I did similar testing but not so methodical as you did. You know I have that T4-Vivitar/Tokina 105/2.8 which I guess is just the same lens as your Soligor.

I tried three 50mm + 2xTcon combos as a comparison, and FWIW the pics all came out more or less the same, be it the glowy full open shot or the better snap when stopped down. I tried the Rear Converter K T6-2x with the SMC-M 1.7/50 and the Kenko Teleplus MC7 and K-mount Lomo Volna MC 1.8/50 and also the Revuenon/Cosina 55/1.2 on the Teleplus.

Your Soligor does fare really well in the full open center, maybe mine is not that good .-)

Best, Georg (the other)

[hinman]

Is there any information about the serial number in Soligor that can tell which company manufactures a Soligor lens. Something similar to Vivitar

There is a recent thread by bc_the_path that asks about the serial number of 38 and mine is 37 on a Soligor 200mm f/2.8 m42 and K mount lens

I am guessing that my copy of Soligor with 37 come from Tokina but it is just a wild guess.

Nice comparison and I love seeing comparison that is not a brick wall I am amateur but I feel really odd in pointing my Pentax bodies on red brick walls. When my boys browse through my photos, I have a difficult time explaining to them what the heck I am doing.

[Nesster]

Yes, Georg, the T4 mounts, whether Soligor or Vivitar, were all Tokina made, as far as I've been able to figure. Hin, I don't know of any list of Soligor serial numbers, perhaps they didn't systematize that way, perhaps they did. One of the Remaining Mysteries... I wonder, if someone could get a grant to ferret out the marketing etc details of the 70s and 80s SLR boom, for a dissertation and online database? Stimulus package, where are you!

Meanwhile, to get you Tak fans off the ledge, or to put down the pitchforks:



Here the focus is more comparable, though the Takumar shot has slightly more exposure than the Soligor side.

At f/5.6 I'd say approximately even, the Soligor has that Tokina cool color, though very sharp. The Tak has the better color, slight edge in contrast...