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08-17-2012, 11:23 AM   #1
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Aperture ring, Green Mode, K lens

I have my Helios 44-2 and Revuenon 50 lens. Helios works with Green Mode, Revuenon doesn't. Why it happens? Why it couldn't be exactly as with Helios?
Thx god, I just found way out for this issue. I used user mode.

08-17-2012, 11:34 AM   #2
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Green mode as in the green mode on the dial or using the green button to set the shutter speed?

As far as I know, neither of those lenses have an A position on the aperture ring, so neither should work properly in any mode except M.
08-17-2012, 02:06 PM   #3
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In Green Mode using Helios 44-2 shooting is available, also shutter speed & ISO are being set automatically.
When I am using Revueno, Green Mode doesn't even work.
08-17-2012, 02:19 PM   #4
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I have a theory, but without pictures of the lenses, I can't know for sure.

Could that Helios be an M42 lens with an adapter put on it? That could potentially explain it, since when you turn the aperture ring, the aperture is actually closing. Auto metering works, but it doesn't quite work properly in this situation.

The Revuenon, being a true K mount, is keeping the aperture wide open until you take the shot, since it doesn't have the A contacts to report the aperture to the body, the body can't meter with the lens wide open.

For best results with lenses like these, green mode is not the best mode to be in anyway.

08-17-2012, 04:33 PM   #5
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QuoteOriginally posted by elliott Quote
For best results with lenses like these, green mode is not the best mode to be in anyway.
I think it reverts to Av anyway.
08-17-2012, 06:39 PM   #6
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Yeah, shoulld switch to Av mode. On my K10D the green button only works in manual or X mode. Preview is set to "Optical" and it closes down a non-A K-mount lens for stop-down metering. M42 mount lenses I have to switch the lens to manual (if so equipped) and stop-down before pressing the green button. Av mode will only work if the aperture is wide open.

Could it be the mount on the Helios is shorting out the pins? What adapter is being used?
08-18-2012, 11:36 PM   #7
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QuoteOriginally posted by elliott Quote
Could that Helios be an M42 lens with an adapter put on it?
Yes. Helios is M42 mount.

QuoteOriginally posted by elliott Quote
Auto metering works, but it doesn't quite work properly in this situation.
Auto metering works perfectly for me. K-5 correctly calculates ISO, Shutter speed for chosen aperture (on ring). Almost all photo have perfect exposure.

QuoteOriginally posted by Not a Number Quote
Could it be the mount on the Helios is shorting out the pins?
Helios is M42 mount lens. All pins don't touch anything. I don't think there is shorting out.

QuoteOriginally posted by Not a Number Quote
What adapter is being used?
I used M42-K adapter with ability to focus on infinity

Before yesterday it seems I'd found way out. I'd set some options in camera (with Revuenon 50 1.4), so there was ability to set aperture (by using aperture ring) and camera automatically adjusts ISO, shutter speed
But now I've lost it. Maybe my friend changes some options. I cant return options to previous version.
Look. Helios have not that pin that allow camera to control aperture. And spinning aperture ring is smoothly and not discrete on all ring range. Therefore when I used for example Av mode camera automatically adjusts ISO and shutter speed for chosen aperture (by spinning aperture ring)
Revuenon 50 1.4 have that pin. So it seems I have to choose between:
1) aperture is always 1.4, camera automatically adjusts ISO & SS
2) I can change aperture, ISO & SS are manual
I thing if I break that pin (that allow camera to control aperture) on Revuenon 50 1.4, it would work as I want. But I don't want ruin the lens.
I want that on chosen aperture, the camera automatically would adjust ISO and SS. How do I do that?

PS: Apologize for my English. If you have some misunderstoods, feel free to ask me. I'll try to give an answer.

Thanks,
Andrii
08-18-2012, 11:49 PM   #8
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QuoteOriginally posted by AndreyS Quote
Auto metering works perfectly for me. K-5 correctly calculates ISO, Shutter speed for chosen aperture (on ring). Almost all photo have perfect exposure.
I never said it wouldn't work, I just said it isn't perfect in all situations with all M42 lenses. The camera can't know the aperture you set, it is just setting the shutter speed based on what it sees, which might not be exactly right at smaller apertures because of the way the stock focus screen works. Don't rely on this too much, it is more of a side effect than an official feature.

QuoteOriginally posted by AndreyS Quote
I want that on chosen aperture, the camera automatically would adjust ISO and SS. How do I do that?
Sell the Revuenon and buy a lens with A contacts, like the Pentax A 50mm f1.4.

Just a thought on the Helios, when you turn the aperture ring, does the viewfinder get darker?

08-18-2012, 11:59 PM   #9
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QuoteOriginally posted by elliott Quote
Just a thought on the Helios, when you turn the aperture ring, does the viewfinder get darker?
Yes, it does.

QuoteOriginally posted by elliott Quote
The camera can't know the aperture you set
I dont think the camera needs to know what aperture currently is. Camera just sees the brightness of picture, and adjusts ISO & SS for it
08-19-2012, 12:02 AM   #10
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QuoteOriginally posted by elliott Quote
Sell the Revuenon and buy a lens with A contacts, like the Pentax A 50mm f1.4
I wanted this lens before buying Revuenon. But I didn't found anybody selling it in Ukraine.
And I really like photos made by this Revuenon lens. Yes the objects are slightly smooth on 1.4. But I don't find this as a problem so far

Last edited by AndreyS; 08-19-2012 at 12:08 AM.
08-19-2012, 12:16 AM   #11
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QuoteOriginally posted by AndreyS Quote
Yes, it does.
That is good, I was just making sure it wasn't one of the Helios lenses with the auto pin that causes the aperture to stay wide open unless modified.

QuoteOriginally posted by AndreyS Quote
Dont think the camera needs to know what aperture currently is. Camera just sees the brightness of picture, and adjusts ISO & SS for it
It is seeing the brightness through the focusing screen, which can be misleading with the stock screen. This is a well documented problem, the stock screen is not linear and can cause inaccurate readings at small apertures. The stock screen is not intended for use with manual focus lenses, since that is not what the average buyer is going to be using.

QuoteOriginally posted by AndreyS Quote
I wanted this lens before buying Revuenon. But I didn't found anybody selling it in Ukraine.
And I really like photos made by this Revuenon lens. Yes the objects are slightly smooth on 1.4. But I don't find this as a problem so far
There is nothing wrong with the Revuenon, it just doesn't support automatic metering, my Pentax M 50mm f1.4 doesn't either. I use manual mode, set the aperture on the lens, hit the green button to set the shutter speed, this works fine about 90% of the time. Sometimes I'll have to tweak the exposure a little, but it isn't a big deal.

If you want full exposure automation without issues, the only possible way to get it is with a lens that supports it.
08-19-2012, 01:18 AM   #12
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QuoteOriginally posted by elliott Quote
If you want full exposure automation without issues, the only possible way to get it is with a lens that supports it.
Or just remove that pin (that allow camera to control aperture) on the lens. Thus camera won't control the aperture

Last edited by AndreyS; 08-19-2012 at 01:27 AM.
08-19-2012, 01:33 AM   #13
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QuoteOriginally posted by AndreyS Quote
Or just break that pin (that allow camera to control aperture) on the lens thus camera couldn't control the aperture
That is not full automation, that is a hack that gives the illusion of automation, it creates more problems than it solves. Use manual mode, use the green button, it is not hard to do and it is more convenient than trying to focus a lens that is stopped down to f8 or open the aperture to focus and then close it again to shoot.
08-19-2012, 05:10 AM   #14
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What is the camera body you are using?
08-19-2012, 11:49 AM   #15
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QuoteOriginally posted by Not a Number Quote
What is the camera body you are using?
Pentax K-5
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