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[SOLVED] Soligor 3x TC won't mount to Nikon D40
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PostPosted: Thu Mar 25, 2010 7:33 am    Post subject: [SOLVED] Soligor 3x TC won't mount to Nikon D40 Reply with quote


Edit: This has now been fixed by modifying the teleconverter. Scroll down a few posts to find the process. Cool


While traveling I picked up a 3x Soligor tele converter for Nikon lenses, but when I tried it out, I found out that it doesn't fit my D40. Sad

It's interesting, because it only turns a few degrees before getting stuck (too tight), and doesn't turn far enough to lock. I determined that the mount flange on the TC is slightly recessed into the TC body, so I removed the mount and tried mounting just that to the camera. This let it turn on quite a bit further, but it still gets tight and stops about 5 to 10 degrees before it would lock.

I tried removing anything that could interfere - the tiny stop screw in the side of the mount flange, as well as the stop-down lever. Neither of these changed anything, so it wasn't an interference issue, the mount is just too tight. Confused

Has anyone seen this before, or have any ideas on how to fix it?

Last edited by Scheimpflug on Fri Apr 02, 2010 8:50 pm; edited 1 time in total

PostPosted: Sat Mar 27, 2010 10:58 pm    Post subject: Reply with quote

I believe 3x converters are crappy, so be happy if not fit into your camera body. Don't waste your time to get work it will shoot soft unusable images I am 90% sure.

PostPosted: Sun Mar 28, 2010 2:58 am    Post subject: Reply with quote

Attila wrote:
I believe 3x converters are crappy, so be happy if not fit into your camera body. Don't waste your time to get work it will shoot soft unusable images I am 90% sure.

That seems to be the general consensus, but I think there are a lot of "hand-me-down" opinions from people who haven't used them... and probably many of the original opinions were from people who had much different criteria than I do... not to mention different budgets. Wink

Here are the primary complaints I hear about with 3x TCs:

Edge/corner sharpness
This may be an issue with 35mm film and full frame digital, but is of less of a concern on a DX format APS-C digital sensor.

Chromatic aberration
A show-stopper problem up to a few years ago, but CA is now easily corrected in software post-processing.

Throws off AF due to low light and/or no electrical/mechanical AF coupling
No problem here! Very Happy

Too much light loss - needs high iso / slow shutter
Just a usage constraint. Not everybody uses telephoto lenses for birds in flight. Wink

Loss of image quality
So you get an image that technically is not as good in terms of sharpness/contrast/etc... but of a subject so small that your non-TC'd lens couldn't even see it. This still sounds useful to me!

Not as good as a single lens of equivalent focal length
Sure.. but that will always be the case. The TC combo is smaller than two lenses, weighs less than two lenses, and costs considerably less than two lenses. You can always spend your way to a better image for a given focal length, but that doesn't make it more practical. Wink

Guaranteed to be dark & blurry
...Except for the fact that there are examples where it does work. Wink For example, here's a user's test with a Carl Zeiss Jena DDR 135mm f3.5 lens on a Nikon D40.. shot on different days, but effectively the same shot with and without a Helios 3x TC.

Full size at: http://www.flickr.com/photos/23327175@N06/3339576216/

Full size at: http://www.flickr.com/photos/23327175@N06/3356792305/in/set-72157615196204637/

So the conclusion is that yes, everyone says a 3x TC is worthless, and no, I don't believe them and want to try it for myself. Very Happy

PostPosted: Sun Mar 28, 2010 10:47 am    Post subject: Reply with quote

A few pictures...

In this first shot, you can see how the mount is just a bit recessed into the barrel of the TC. I think fixing this is as easy as removing the mount and the optics, and then sanding the empty barrel on a flat surface. Since the barrel isn't the mounting surface to the camera or to the mount on the TC, I can trim it down without worrying about changing the TC alignment.

I then checked to be sure that the locking notch in the mount was actually in the correct spot, by comparing it with a lens that mounts correctly:

I did notice that the mounting tabs are narrower, but aside from that, it appears as though things are in the correct spots.

So I suppose I have two options... I can either attempt to file the under sides of the mounting tabs just a touch to make them thinner, or I can grind a new locking notch at the place where the converter stops turning. I have no idea which would be preferable... I'll have to think about it.

PostPosted: Fri Apr 02, 2010 11:32 am    Post subject: Reply with quote

For anyone watching, I was able to successfully modify the TC. Cool

First, I made some markings on the outer housing of the TC. The red arrow is the indexing mark that matches the mark on the camera body, and the blue arrow is where the locking slot is located.

With these marks made, I was able to put the TC on the camera body and see just how far off it was. As you can see, I was only able to rotate the TC a few degrees before it would stop turning. Sad

To start the modification, I unscrewed the mount & optics assembly from the TC body, and then removed the aperture coupling prong & fork to prevent damage.

I then placed the empty TC body on a piece of 180-grit sandpaper - the kind designed for metals with the waterproof backing - and spent about 20 minutes slowly removing material from the TC barrel. I did orbiting motions and rotated the TC every minute or so to keep things square, but the material I removed was just cosmetic. The actual surface that the mount sits on is on the inner groove, so it is unaffected by this process. To finish the surface, I went over the same sandpaper but with a very very light touch, then I "rolled" the outer edge on the sandpaper to de-burr the outer edge and give it a nice polished look to match the factory finish. I de-burred the inner edge of the lip with a small nail file.

Note that aluminum dust is the last thing you want inside a camera. While working on this piece, I made absolutely certain that the TC stayed in the same orientation (dust side down), and I thoroughly cleaned it with rubbing alcohol inside and out (on all sides, even the top) while it was still in that orientation. No test-fitting or re-assembly was done until it was completely clean.

When finished, the lip on the outside was noticeably shorter. A quick test fit of the mount/optics assembly revealed that I was all set. I took off just a bit more material than necessary, but my clearance problem was definitely taken care of as the mount was now taller than the TC body. Cool

A test fit on the camera shows that it fits! Note that the red arrow (the indexing mark) has now rotated all the way to the top, and the blue arrow for the locking slot is now at the camera latch. I had thought that there was more holding it back, but it turns out that I just didn't have anything to hold onto when I was test fitting the mount on its own, so my hand would slip. The mount itself is A-OK, the TC body was the only problem. Cool

One last step in the re-assembly.. I decided to leave the coupling fork off of the TC, as it isn't used with the Nikon DSLRs. However, I put the coupling prong back on, so that it can couple to my older lenses to give them the extra aperture ring.

... and that's it! Very Happy I'm pretty happy with the outcome. It now mounts perfectly, and even if you examine the TC very closely, you can't tell that anything was done to it. It looks completely factory.

PostPosted: Sat Apr 03, 2010 1:30 am    Post subject: Reply with quote

Very nice work! I think that was your best option.Now you don't have to wory about your lens and Tc dropping off. Surprised Shocked