Forum: Troubleshooting and Beginner Help
12-07-2016, 06:52 PM
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Dang, I wish I had a K-50 in hand! There is some variation in how the various Pentax bodies work in regards to stop-down metering with adapted lenses. All will adjust shutter speed in Av mode as you stop down a manual aperture lens. Most will also meter with the green button in M mode using a manual aperture lens, though some will not.
Av mode metering is full time. M mode is "set once and shoot". There are pluses and minuses to both. You can't do manual metering (sunny 16 or hand-held) in Av mode.
That is expected for all non-AF lenses.
Half the light disappears for each full stop.
Seeing becomes more difficult as the viewfinder dims. Yes, it does affect the outcome since you are seeing the same light that strikes the sensor. Remember, though, that ISO and shutter speed make up the rest of the exposure triangle.
The matter of viewfinder dimming has implications as far as work flow and most users find a sequence that works for them. The bullet points for adapted M42 lenses go something like this:- Your best manual focus performance will be with the lens wide open
- Unless you intend to shoot wide open, the aperture must be stopped down at exposure time
- The above two points place the user of adapted M42 lenses back to the earliest days of SLR photography where manual lens stop down was the norm and the photographer was frequently having to open the aperture up to focus and stopping it back down to shoot.
How this requirement translates depends a lot on whether you use M or Av modes. In Av mode, the shot sequence goes something like this:- Lens A/M switch in M position and aperture wide open
- Focus on subject
- Rotate aperture ring to narrower openings until either the desired f/stop is reached (count the clicks) or the desired shutter speed is displayed. The viewfinder will dim as your stop down.
- Make your exposure
- Repeat above steps for additional exposures
A variation of the above is to set the aperture ring in advance and use the A/M switch to move from wide-open to stopped down to make the shot. If exposures are too light or too dark, use exposure compensation to provide shorter or longer exposure times. M mode works something like this:- Determine and apply exposure settings
- For bodies that support green button in M mode with adapted lenses you may stop the lens down to the desired aperture and push the green button to set the appropriate shutter speed
- If using best guess, "sunny 16", or a hand-held meter; simply set the desired aperture and shutter speed directly.
- Focus on subject with aperture wide open
- Stop down lens
- Take photo
- Repeat from step two until either the light or subject changes
This is all much easier than it sounds and actually helps reinforce a good understanding of exposure and the things that the cameras usually does for you.
Steve
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Forum: Troubleshooting and Beginner Help
12-04-2016, 05:46 PM
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Good question. I tested one of my taks on my friend's K-50 when she got it two years ago, and seem to remember that it worked, but that CIF did not.
Steve
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Forum: Troubleshooting and Beginner Help
12-04-2016, 05:09 PM
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I don't think so. I believe the camera will default to manual ISO. Edit: I am probably wrong here, though it is easy enough to check.
No, both should be active when not using live view. Focus confirmation is a red square at center of the viewfinder and green hexagon in the status bar across the bottom and a beep.
F--- is displayed whenever the body is not able to set the aperture. Since the aperture is set on the aperture ring and is unknown to the body, F--- is displayed instead.
Steve
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Forum: Troubleshooting and Beginner Help
12-04-2016, 09:25 AM
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Some people find it useful, but as you have probably figured out, it is a special technique useful as a means to "trap" the subject at the moment focus is attained. The peril is that there is lag time during which the subject may move out of focus or, for when the user is actively moving the focus ring as the "trap", the ring may move past the right position before or actually during the exposure. The latter results in a frame where the bottom of the subject is potentially sharper than the top!
Steve
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Forum: Troubleshooting and Beginner Help
12-04-2016, 09:20 AM
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Not needed unless you are on tripod. In that case, the easiest way to shut SR off and to also dampen mirror vibrations is to use the 2s delay or the self-timer.
Steve
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Forum: Troubleshooting and Beginner Help
12-03-2016, 03:48 PM
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This is generally true for AF-S, AF "on" with K-mount lenses, but the OP is using a K-50 with adapted M42 55/1.8. IIRC, the K-50 is one of those models where catch-in-focus will not work with lenses having a non-conductive (painted or anodized) base. If my memory is wrong, please feel free to correct. (I don't have a K-50 at hand.)
Magnified live view (press-hold OK button) is the gold standard for manual focus accuracy, but works best when used on-tripod. I am not found of focus peaking (does not work well with some subjects), but to each his own. For more advanced users, an aftermarket focus screen with split-image/microprism focus aides is another option. They work well, but have trade-offs in terms of usability and the need to adjust screen calibration with shims.
Steve
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