Exposure bracketing: can the camera please change only one variable?

87 posts
18 years

Posted 18/07/2010 - 17:26 Link

Sometimes, I like to take a 3-shot bracketed exposure for landscapes and things. Well to change the exposure from shot to shot, it seems Pentax cameras like to modify the shutter speed AND the sperture from shot to shot.

So my three shots would be 1: 1/250, f8 2: 1/160, f6.3 3: 1/125, f5.6

So my depth of field is changing from shot to shot along with the exposure. NOT USEFUL!

Does anybody know if I can isolate which aspect I'd like to bracket? Let's say I want to only bracket the shutter, or only bracket the aperture, or only bracket ISO - how do I set that? (I'm using both the K10 and the K7, so I'd like to know if it's possible on either camera)

Edited by Dubious Drewski: 18/07/2010 - 17:27

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johnriley johnriley

24430 posts
24 years
Tyldesley,
Manchester

Posted 18/07/2010 - 17:34 - Helpful Comment Link

If you want to keep the aperture the same, set Av and select your aperture. It will stay the same until you change it and the shutter speed will vary to compansate for changing light.

To bracket, use exposure compensation to alter the exposure anywhere from -3EV to +3EV (more on the K7) and the aperture will still stay the same. I allocated exposure compensation to the front dial when set in Av, and change the aperture with the rerar dial.

If it's the shutter speed you want to set, then use Tv and let the camera change the aperture.

That's how it works!

Best regards, John

Dubious Drews... Dubious Drewski

87 posts
18 years

Posted 18/07/2010 - 17:40 Link

Well geez. Thank you. I knew it had to be simple like that! I've always been trying it in M or TaV.

Well that means I've found an inconsistency in Pentax's design. If in a bracketed shot, Tv locks the shutter and Av locks the aperture, why doesn't TaV lock both and make the ISO vary?

Oh well, it's not really that important.

Thanks again, John.