deaner66 Posted March 30, 2008 Share Posted March 30, 2008 Maybe someone can help.... I'm still getting to know my K10d. With my 16-45 zoom everything goes smooth.The problems start when I use my SMC-M lenses. My 50mm 1.7 and my 135mm 3.5.They take great pictures. Very sharp. The problem is the exposure and the way the camera handles it. I've read a lotof threads about the problems with exposure and the M lenses. And I getit...unless you change focusing screens, the exposure will be off slightly. What I don't understand is when I get the exposure right and take a goodpicture, the camera, almost automatically changes the shutter speed for the nextpicture. In other words, I constantly have to change my settings with everysingle shot. Is this normal, and why does this happen? Thanks,Steve Link to comment Share on other sites More sharing options...
jgredline Posted March 30, 2008 Share Posted March 30, 2008 Steve, What mode are you shooting in? Link to comment Share on other sites More sharing options...
michael_kuhne Posted March 30, 2008 Share Posted March 30, 2008 Steve, the focussing screen has nothing to do with exposure. Everything can be totally out of focus, yet with correct exposure. As I understand it, you should enable aperture ring use in Custom menu, shoot in manual mode, then use the green button for the camera to set the shutter speed for correct exposure. Link to comment Share on other sites More sharing options...
miserere_mei Posted March 30, 2008 Share Posted March 30, 2008 Michael, some people report better exposure behaviour with old lenses when they use a different focusing screen, like a KatzEye or Chinese eBay Special. Steve, each lens has its quirks, and you'll have to learn to adapt to them. Nothing we can say will beat your own experimentation. Link to comment Share on other sites More sharing options...
johnmarsden Posted March 30, 2008 Share Posted March 30, 2008 Hi Steve, I have only done a little bit with an old MF lens. This was a Vivitar 28mm F2 - Great in its day and still quite good. Anyway the K10d has no idea what the Vivitar is doing so you have to take full control. Select one iso - not an auto range Set manual mode to set speed and aperture For metering (and this is the bit I'm not totally clear about.) I use the DOF preview - that is the on/off button thingy turn it even more on as it were. The camera metering then tells you how under or over exposed your setting is. Then twiddle your settings to get the exposure right. Now as I understand this it HAS to be 'correct' since it is metering what will be coming down the lens to the sensor. I understand that you can press the green button for exposure setting, but it is my guess that unless the camera knows what max aperture the lens is set to then it has no way of really knowing what the correct exposure should be eg if your lens is at f4 or an f1.8 etc how does the camera know this if using older lenses? I dunno 'cos I'm not a techie type. Also get used to using histograms NOT the image on the review panel to check your exposures. Link to comment Share on other sites More sharing options...
jerry thirsty Posted March 30, 2008 Share Posted March 30, 2008 Did you turn on auto-bracketing at some point and forget to turn it off? Link to comment Share on other sites More sharing options...
deaner66 Posted March 30, 2008 Author Share Posted March 30, 2008 Javier: In M mode as always. John: I've used the Optical DOF preview and unfortunately it comes out different than the actual shot. This is what confuses me. This does this with both of my SMC-M lenses. As I also said, even if I take an acceptable shot, the camera switches the shutter speed either up or down a notch. Jerry: You got me thinking. I don't think I ever turned this on, because I don't have this problem with my 16-45 AF zoom. But I need to confirm this. Link to comment Share on other sites More sharing options...
deaner66 Posted March 30, 2008 Author Share Posted March 30, 2008 Jerry solved my problem, I believe. Turns out exposure bracketing mode was on. I don't remember setting it, but it was on. I still have the problem with the spotty metering with the SMC lenses. And I've read in many places that other focusing screens will aid in metering with the older lenses. Thanks for the help. Link to comment Share on other sites More sharing options...
peter_schluter Posted March 31, 2008 Share Posted March 31, 2008 The Focus screen does affect metering when the Stop-down (green button) metering method is used. Pressing the green button causes the lens to stop-down and the camera reads the actual light hitting the meter. Because this is located above the focus screen, and the light has to travel through the screen the type of screen does make a difference. I put a DS screen into my k10 and it cured the progressive overexposure. The green button method of metering does not need to know which aperture is set on the lens because it is measuring the actual light which will eventually fall on the sensor, it just does not do it very well with the stock screen. I am a bit confused that you say the camera was set to exposure bracketing....this does not work in manual mode ?? If you were using Av mode you should be aware that the lens will not stop down at all, wherever you have set the aperture on the lens itself. Like another poster I too use the DOF preview button to turn on the meter and use this as an alternative to the green button method. All the above obviously applies to using M and "K" lenses on the K10. Peter Link to comment Share on other sites More sharing options...
deaner66 Posted March 31, 2008 Author Share Posted March 31, 2008 Peter: It changes the shutter speed when it is in exposure bracketing. No matter what I did, and no matter how perfect my shot, it would change the shutter speed. Not always, but about two out of every three shots, which is about right, because it was set on 3. Also, I use the optical preview for DOF, and often, it isn't real accurate with the actual shot. Maybe this has to do with the focusing screen too. I don't know Link to comment Share on other sites More sharing options...
peter_schluter Posted April 1, 2008 Share Posted April 1, 2008 Steve I will have a look when i get home.... i was under the impression the exposure bracketing did not work in manual mode, but i could be wrong. Not sure what you mean by DOF prview not being accurate.. do you mean the exposure meter reading doesn't seem right or the DOF itself ? I love using the old K and M lenses on the K10 but you do need to change the focus screen to get a correct exposure reading from the meter. This applies whether you use the green button or DOF button to turn on the meter. Peter Link to comment Share on other sites More sharing options...
peter_schluter Posted April 1, 2008 Share Posted April 1, 2008 Steve....looks like I was wrong on the Auto bracket in manual mode. I havnt tried it yet but looking at the manual there is nothing to say you cannot use it in manual. I have learned something new. Peter Link to comment Share on other sites More sharing options...
deaner66 Posted April 1, 2008 Author Share Posted April 1, 2008 Peter: I've read here and on PentaxForums that unless you change focusing screens, only a few f/stops are accurate with the older non-A and AF lenses. They're consistent, but inaccurate. I haven't gotten out and shot with the M lenses since I fixed my exposure bracketing problem, so I will see how it changes things. Link to comment Share on other sites More sharing options...
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