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09-13-2018, 05:08 PM   #1
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Manual expose issues with non-kmount lenses

So I have a K2S and an adapter for Exakta mount to K mount. When shooting in manual mode, ASA fixed to 400, I meter stopped down with the green button and images come out over exposed. I end up shooting 2 stops under the cameras recommended reading for a proper exposure. I have no problem with KA mount or DA lenses. Am I doing something wrong? Lenses I've mounted have been the Meyer Gorlitz 58mm f/1.9 preset, Zeiss Jena 58mm f/2 semi-auto, Zeiss Jena 80mm f/2.8 Tessar preset and late model Schneider 35/2.8, 50/1.9 and 135/3.5. The issue is the same for all these lenses.



09-13-2018, 05:18 PM   #2
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QuoteOriginally posted by tonyzoc Quote
So I have a K2S and an adapter for Exakta mount to K mount. When shooting in manual mode, ASA fixed to 400, I meter stopped down with the green button and images come out over exposed. I end up shooting 2 stops under the cameras recommended reading for a proper exposure. I have no problem with KA mount or DA lenses. Am I doing something wrong? Lenses I've mounted have been the Meyer Gorlitz 58mm f/1.9 preset, Zeiss Jena 58mm f/2 semi-auto, Zeiss Jena 80mm f/2.8 Tessar preset and late model Schneider 35/2.8, 50/1.9 and 135/3.5. The issue is the same for all these lenses.
No aperture lever? Please have a look at this thread: Using Manual Lenses (M42 Screwmount, M , K) on Pentax DSLRs F-- - PentaxForums.com

Specifically, this thread: https://www.pentaxforums.com/forums/53-pentax-dslr-camera-articles/100260-ma...ic-lenses.html
09-13-2018, 05:25 PM   #3
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My recommendation would be to use live view for metering, as then you're not limited to the center point.

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09-13-2018, 05:59 PM - 1 Like   #4
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QuoteOriginally posted by tonyzoc Quote
The issue is the same for all these lenses.
To summarize the above and add a bit:
  • You may get better results using green button in live view
  • Be sure the lens is set to be fully manual aperture and that the actual aperture opening is proper for its setting. I have several Zeiss Jena lenses for Exakta and most have lazy or inoperable apertures.
  • Once you have the settings from live view, there is no need to meter again unless the subject or light changes (say cloud passes over the sun). Set the camera back to the optical viewfinder and shoot at will.
I am curious in regards to results. Without a glass element in the adapter, Exakta mount lenses will not focus to infinity when adapted to Pentax-K. Unfortunately, that extra element usually degrades optical performance.


Steve

09-13-2018, 06:26 PM   #5
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The Schneider Autos have the Exakta side arm....I use them in manual diaphragm mode. The presets I stop down as to desired fstop.

So... Live view did give me correct metering. Here are 2 examples shot at f/4 at 1/20 hand held ( so not as sharp as they could be) with the Ziess Biotar 58mm.



---------- Post added 09-13-18 at 06:27 PM ----------

QuoteOriginally posted by stevebrot Quote
To summarize the above and add a bit:
  • You may get better results using green button in live view
  • Be sure the lens is set to be fully manual aperture and that the actual aperture opening is proper for its setting. I have several Zeiss Jena lenses for Exakta and most have lazy or inoperable apertures.
  • Once you have the settings from live view, there is no need to meter again unless the subject or light changes (say cloud passes over the sun). Set the camera back to the optical viewfinder and shoot at will.
I am curious in regards to results. Without a glass element in the adapter, Exakta mount lenses will not focus to infinity when adapted to Pentax-K. Unfortunately, that extra element usually degrades optical performance.


Steve
I have the adapter with the glass element. You see them on eBay for about $50.
09-13-2018, 06:36 PM   #6
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QuoteOriginally posted by tonyzoc Quote
The Schneider Autos have the Exakta side arm....I use them in manual diaphragm mode. The presets I stop down as to desired fstop.

So... Live view did give me correct metering. Here are 2 examples shot at f/4 at 1/20 hand held ( so not as sharp as they could be) with the Ziess Biotar 58mm.



---------- Post added 09-13-18 at 06:27 PM ----------

I have the adapter with the glass element. You see them on eBay for about $50.
Glad you got it sorted out


Steve
09-13-2018, 06:38 PM - 1 Like   #7
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QuoteOriginally posted by stevebrot Quote
To summarize the above and add a bit:
  • You may get better results using green button in live view
  • Be sure the lens is set to be fully manual aperture and that the actual aperture opening is proper for its setting. I have several Zeiss Jena lenses for Exakta and most have lazy or inoperable apertures.
  • Once you have the settings from live view, there is no need to meter again unless the subject or light changes (say cloud passes over the sun). Set the camera back to the optical viewfinder and shoot at will.
I am curious in regards to results. Without a glass element in the adapter, Exakta mount lenses will not focus to infinity when adapted to Pentax-K. Unfortunately, that extra element usually degrades optical performance.


Steve
Btw...the Zeiss lenses are pretty easy to disassemble and clean (except for the old brass ones from the 30s). The semi-auto and autos are easy to remove the front and rear lens groups, the you can clean the diaphragm and loose the focus without any additional disassembly. I use light fluid to flush she diaphragm, catching runoff with tissue...work it and keep flushing. Then I dry with a heat gun...and use qtips to clean off the surfaces. If I see an Exakta Zeiss with cloudiness or stuck diaphragm I always pick them up. The cloudiness in 90% of the time, just oil residue from inside the diaphragm chamber...wipes of easy.



---------- Post added 09-13-18 at 06:43 PM ----------

QuoteOriginally posted by stevebrot Quote
To summarize the above and add a bit:
  • You may get better results using green button in live view
  • Be sure the lens is set to be fully manual aperture and that the actual aperture opening is proper for its setting. I have several Zeiss Jena lenses for Exakta and most have lazy or inoperable apertures.
  • Once you have the settings from live view, there is no need to meter again unless the subject or light changes (say cloud passes over the sun). Set the camera back to the optical viewfinder and shoot at will.
I am curious in regards to results. Without a glass element in the adapter, Exakta mount lenses will not focus to infinity when adapted to Pentax-K. Unfortunately, that extra element usually degrades optical performance.


Steve
Oh...also regarding the adapter...many wide angle lenses won't focus to infinity be because the rear element sits back too far. Even the Schneider 35mm won't go to infinity. The 40mm make kilars also give me trouble...I don't even bother trying my 28mm or 20mm. 50mm and up work well though.

09-13-2018, 06:57 PM   #8
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QuoteOriginally posted by tonyzoc Quote
Btw...the Zeiss lenses are pretty easy to disassemble and clean (except for the old brass ones from the 30s). The semi-auto and autos are easy to remove the front and rear lens groups, the you can clean the diaphragm and loose the focus without any additional disassembly. I use light fluid to flush she diaphragm, catching runoff with tissue...work it and keep flushing. Then I dry with a heat gun...and use qtips to clean off the surfaces. If I see an Exakta Zeiss with cloudiness or stuck diaphragm I always pick them up. The cloudiness in 90% of the time, just oil residue from inside the diaphragm chamber...wipes of easy.
I may tap your expertise at some point. I reviewed your posts and noticed that you do film photography with Exakta and have a Varex IIa. I have the same model, but have not put any film through it yet. Are you familiar with the "Lets see those film shots" thread? It is for film photos with no restrictions on brand or format. There is at least one Exakta shooter that posts there and I am sure your contribution will be valued.

https://www.pentaxforums.com/forums/8-pentax-film-slr-discussion/53503-cool-...ilm-shots.html


Steve
09-13-2018, 07:15 PM - 1 Like   #9
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QuoteOriginally posted by stevebrot Quote
I may tap your expertise at some point. I reviewed your posts and noticed that you do film photography with Exakta and have a Varex IIa. I have the same model, but have not put any film through it yet. Are you familiar with the "Lets see those film shots" thread? It is for film photos with no restrictions on brand or format. There is at least one Exakta shooter that posts there and I am sure your contribution will be valued.

https://www.pentaxforums.com/forums/8-pentax-film-slr-discussion/53503-cool-...ilm-shots.html


Steve
I am primarily an Exakta collector and user. I've got about 70 Exaktas and 75+ lenses. I fix my own Exaktas. I can disassemble and make and replace shutters. Also I got a supplier of first surface mirrors. I don't do repairs for others because I just don't have the time (and I have a side business that pays more than fixing Exaktas would). I do have plans to video the shutter curtain making I do, and the CLA process....someday. As for shooting, I do a fair amount but I don't have a decent scanner. Lately I started sending my film yo The Darkroom for process and scanning. I got a couple of rolls done...and another 5 or 6 in my fridge ready to send out. I'll try to find a few to post.

09-13-2018, 10:14 PM   #10
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QuoteOriginally posted by tonyzoc Quote
I am primarily an Exakta collector and user. I've got about 70 Exaktas and 75+ lenses. I fix my own Exaktas. I can disassemble and make and replace shutters. Also I got a supplier of first surface mirrors. I don't do repairs for others because I just don't have the time (and I have a side business that pays more than fixing Exaktas would). I do have plans to video the shutter curtain making I do, and the CLA process....someday. As for shooting, I do a fair amount but I don't have a decent scanner. Lately I started sending my film yo The Darkroom for process and scanning. I got a couple of rolls done...and another 5 or 6 in my fridge ready to send out. I'll try to find a few to post.
I'd love to see that video!
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