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Old Nov 5, 2010, 8:35 AM   #11
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Jachol,

It's been a long time since I've seen one of these teleconverters, but back in the day, many cameras had a small view window in the prism so that you could read the aperture off of the exterior of the lens barrel and see the setting in the view finder. I seem to remember that you would set the lens to the widest aperture and you could then stop down the lens with the aperture ring on the teleconverter, and the teleconverter had the adjusted scale on the ring so that what you saw in the view finder was the corrected aperture, ie: if you set the lens to 1.4 you would see the real setting of 2.8 when you looked through the view finder. Don't hold me to that as it's probably been about 30 years or so since I was using a Spotmatic, but that is what I seem to remember.

Steve
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Old Nov 5, 2010, 10:16 AM   #12
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Originally Posted by Odinz View Post
Jachol,

It's been a long time since I've seen one of these teleconverters, but back in the day, many cameras had a small view window in the prism so that you could read the aperture off of the exterior of the lens barrel and see the setting in the view finder. I seem to remember that you would set the lens to the widest aperture and you could then stop down the lens with the aperture ring on the teleconverter, and the teleconverter had the adjusted scale on the ring so that what you saw in the view finder was the corrected aperture, ie: if you set the lens to 1.4 you would see the real setting of 2.8 when you looked through the view finder. Don't hold me to that as it's probably been about 30 years or so since I was using a Spotmatic, but that is what I seem to remember.

Steve
Hi Steve,

Thanks for that input ... You could well be right, I received this the TC this morning, and in fact it doesn't have a aperture ring of it's own as I thought it might, it appears to me that if you set it to the aperture of the lens you use it with, it displays the effective aperture of the combination, ie. if your basic lens aperture is 2.8 say, it displays 5.6 in the small window below the ring , which is correct for a 2X TC which it is. (the clue was there in the pic above, it just didn't click). I've never seen or heard of one like it before.

It obviously wont do the job I thought it might, but no loss I bought it cheaply, and the item and it's case are in mint condition, I doubt it's ever been used. I've no doubt I can sell it on, I don't think I have need of an M42 2X TC.

I will run a few tests first to see how well or how badly it affects the IQ ... out of curiosity.
The project of using it as an aperture control is dead in the water, so it's back to investigating the lens Viv lens mechanics, I've an awful feeling there's nothing there to resurrect though. ... Jack.
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Old Nov 5, 2010, 4:10 PM   #13
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Hi Jack,

If all else fails, you can get smaller apertures by blocking the front of the lens and have pre-measured cutouts of different diameters -- about as manual as you can get. 1 stop = 1/2 the light so for each stop, you'd need 1/2 the area of the previous cutout. You could focus without the cutout (wide open), then meter with it in place, and you could have endlessly variable bokeh effects with different shape cutouts.

I think you can make this a fun project.

Scott
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Old Nov 6, 2010, 9:59 AM   #14
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Hi Jack,

If all else fails, you can get smaller apertures by blocking the front of the lens and have pre-measured cutouts of different diameters -- about as manual as you can get. 1 stop = 1/2 the light so for each stop, you'd need 1/2 the area of the previous cutout. You could focus without the cutout (wide open), then meter with it in place, and you could have endlessly variable bokeh effects with different shape cutouts.

I think you can make this a fun project.

Scott
I guess that would work fine Scott, I'll try it at a later date though, first thing will be to have another look inside the lens. That too must be backburnered for a while ... I have a couple of household projects on the go that must be finished for Xmas before my family arrives home for the break, I've been immobilised most of this year with severe sciatica, so things got away from me, and I need to catch up.

Many thanks to all who gave input, I'll try and add more if and when there's progress. ... Jack.
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