K-5 exposure: difference between LV & Viewfinder

I am interested to know if anyone has this problem or has an idea of how I might correct it.

Is there any reason why my K-5 should give a different exposure for live view from that which it gives when viewed through viewfinder? The result is that live view images are brighter and viewfinder images noticeably darker.

To check this, I have used a stand and maintained identical settings with images taken just a few seconds apart. The difference is most noticeable with the DA70mm lens but is evident to a greater or lesser extent in all my lenses.

Any insight would be most appreciated.

Good point, John. I don't wear glasses except for reading and of course to use the LED screen in live view, but when using a stand I often use a delayed shutter release and do not cover the viewfinder. I will do a series of experiments to ascertain if light leaking through the viewfinder is the problem.

Sounds like I may have found a use for the viewfinder cover at last!

Thanks for the tip,

Ronnie

Clever

I remember, when I bought my Spotmatic in 1970,the competition Minolta, I think it was the SRT 101, had a 3rd photosensitive device in or near the viewfinder, to compensate for stray light in to the viewfinder..
I wonder why it is not used in the current cameras.

Some cameras also had a sliding cover for closing the viewfinder window when using a tripod and cable release. This should be easy enaugh to do now, instead of this idiotic slid on cover, which gets lost after or just before the first use.

Regards, Horst

I don't use the viewfinder cover, I just shield the finder with my hand. It's important not to touch the camera whilst doing this, in case it gets nudged. Coupled with using the 2 second timer it seems to be a trouble free approach.

I take a fair few exposures of several minutes, so shielding with the hand is not an option. I have made a cover out of a piece of box card, cut to shape and covered with black tape. This slots under the rubber that surrounds the eyepiece and this is sufficient to hold it in place. No light leakage occurs and it doesn't matter if the bit of card gets lost as I'll just make another one.

Regards
David

I have noticed this and put it down to the fact that using the viewfinder, you use the 77 segment meter, but in live-view it is using a different means of calculating the correct exposure (ie NOT the 77 segment meter) as that is no longer part of the light path. Is that feasible?

(that is in addition to light leak that John has mentioned when set up on a tripod and eye is away from the viewfinder)