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10-23-2011, 04:34 AM   #1
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K-r vs DS Tungsten Focus

Ok, I know this is a tired issue. So those who's had enough can just moving along.

For those interested, read on.

K-r firmware is 1.11, against my old DS (for those not in the know, this model came out in September 2004).

I used the kit lens on both, set focal length to 55mm, and ISO to 400. I set focus all the way down before I auto focus. Used a tripod. Nothing scientific.

I just cropped the pics to 100% and adjusted levels as the shots were a bit underexposed.

K-r AWB
ISO: 400
Exposure: 1/6 sec
Aperture: 5.6
Focal Length: 55mm


DS AWB
ISO: 400
Exposure: 1/8 sec
Aperture: 5.6
Focal Length: 55mm


K-r has better AWB, DS has better focus. Note that in this case the DS didn't focus at all (yes it's that dim). I had to manually focus it first, then AF after.

K-r Tungsten WB


DS Tungsten WB


K-r focus improved a tad. DS is still the same. I guess you one wouldn't notice the difference without pixel peeping.

K-r LV AWB


I think this is the same as the DS.

My conclusion is that the latest firwmare (1.11) has diminished the front focus in Tungsten light (my previous tests with older firmware here). It's not perfect as the 7 year old tech, but it focused in a fraction of a second where the DS couldn't focus at all.

I guess it's the choice of getting a lousy shot vs not getting one at all. Then again, one could argue Canikon users don't get this problem...

Again this is nothing scientific, and I don't know how much it would affect real world shots.

Btw, I have one series comparison shots, but maybe I've shown too much already. Thanks for looking.

10-23-2011, 05:24 AM   #2
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I havent faced any problems with the autofocus in tungsten. Also, in tungsten lightning i usually use my 50mm f1.7 (manual focus), so...
10-23-2011, 06:42 AM   #3
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Front focus issue only affects contrast detect AF.
10-23-2011, 07:20 AM   #4
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Anyway, thanks for those tests ...
I havent updated my firmware yet...and probably wont, as everything is working for me :P

10-23-2011, 07:24 AM   #5
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Welcome. Just to make it clear, this is not a bashing thread. Just putting things in perspective.
10-23-2011, 01:59 PM   #6
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QuoteOriginally posted by GrinMode Quote
Front focus issue only affects contrast detect AF.
The K-r uses phase detect AF in all modes except LiveView, and switches to contrast detect AF when in LiveView.
10-23-2011, 03:49 PM   #7
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You are right. That's what I meant. Sorry about that. It was late last night when I posted that

10-23-2011, 04:26 PM   #8
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All good, simple mistake. Interesting pics you posted.

For my own part, I've only needed to shoot under tungsten light a handful of times so far, but haven't had any issues with it yet. Shortly after I got my camera, I thought I was having an issue with it, but it turned out to be a lens that wasn't focusing true under any circumstance (this wasn't the kit lens).
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55mm, awb, camera, ds, focus, iso, k-r, kr, length, pentax k-r, shots, tungsten, wb

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