Soligor 400/6.3 (pics) & Slow Aperture Pin

A100 + Soligor 400mm/6.3 (also Spiratone & other related brands) - T4 mount lens in M42 mount with M42-MAF adapter. I first learned of the Soligor 400mm from this guy's blog post.

at f/6.3, handheld


100% crop 1 (center)


100% crop 2 (somewhat off-center)


Sorry no corner crops (corners fell outside the plane of focus anyway, and ripples in the water make it hard to determine sharpness at the left & right edges). Contrast in this image is poor due only to overexposure, my fault.

A cleaned up version:


CA is heavy when shooting wide open, as you can see. Stopping down to f/11 helps significantly.

I'm not sure I have a sense yet of the sharpness or softness of images produced with this lens -- its heavy, all-metal construction and its length, and its slow 6.3 aperture, make it difficult to get sharp shots without a tripod, and then, even with a tripod, focusing is tricky. I suppose a chipped adapter (SSS, focus confirm) might help.

Tripod shots will follow -- after I take a few more & get them uploaded.

**original post follows**

Hello, working on getting a T4 (interchangeable) mount lens to M42, then an M42-->MAF adapter to get the lens on my A100. The T4 M42 mount I bought has the very nice feature of a manual aperture stop-down switch, like what you find on some M42 lenses, great for stop-down metering/shooting.



Here's the problem: the pin on the T4/M42 mount is slow in opening and closing the aperture blades. This causes the aperture to behave like there is oil on the blades (there is no oil on them, as confirmed by using the T4/MD mount & just flipping the aperture open & closed). So the aperture pin and/or manual stop-down switch is/are not snappy.

Can I oil the aperture pin and/or stop-down switch? If so, what kind of oil do I use?

Or, conversely, should I degrease the pin/stop-down switch?

Edited by alpha_in_exile - 24 May 2009 at 19:22

Updated with the beginnings of a review.

If you think the issue is within the adapter, you might check this link regarding how to open it, and what is inside.
However, I am surprised to hear that it might be the adapter which is slow, as mechanically it is very simple, and there is no grease at all within it.
Are you sure that it is the adapter and not the lens which is slow? You might check it by manually actuating the aperture pin on the lens without the adapter.

btw, it is this lens, right? :




edit:
There should be no oil on the aperture and aperture actuator mechanism.
Alternatively, you might also want to permanently lock the adapter in stopped down position (like I did), especially if you are only using it with this lens. Anyhow, the only aperture stops which might be interesting on this lens are 6.3, 8 and 11, so at worst you would focus "wide" open, and count up to 2 aperture clicks to stop down.

Edited by Gabriel - 23 May 2009 at 23:15

alpha_in_exile wrote: Yes, that is the lens. Quite an awkward beast, isn't it?

At least it is not heavy (just 1kg is quite reasonable regarding its size), but it is long enough to be laughable, especially when you compare it to a 300/5.6 mirror lens: