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11-10-2010, 07:14 AM   #16
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QuoteOriginally posted by ovim Quote
Also shooting under tungsten light might cause autofocus error?
Ive noticed this big time. More with some lenses/focal lengths then others though. Under other lighting its pretty dead on though

11-10-2010, 04:02 PM   #17
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HI, I am considering a k-r? How bad is the AF problem? Do you think it can be solved with firmware update?
11-10-2010, 04:39 PM   #18
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QuoteOriginally posted by marubex Quote
HI, I am considering a k-r? How bad is the AF problem? Do you think it can be solved with firmware update?
There is no AF problem.

There is a bit of a backfocus with some lenses in Tungsten (most light bulbs), I have two tamrons, 17-50 which bf pretty bad at 50mm especially in tungsten, I also have a 90mm macro tamron and that one bf only a small amount if at all. This seems to be true of all cameras as far as I know, some like Canons have the issue in flourescent not tungsten. The AF still locks on like it normally would, the focus (after the shot) is just shifted back

The AF in the K-r as far as I have been able to tell is very fast and although Ive only really been using centre point seems very accurate in all light.

The screwdrive motor is also beefed up from the k-x helping with focus speed when using screwdrive lenses
11-10-2010, 10:54 PM   #19
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QuoteOriginally posted by Deimos Quote
There is no AF problem.

There is a bit of a backfocus with some lenses in Tungsten (most light bulbs), I have two tamrons, 17-50 which bf pretty bad at 50mm especially in tungsten, I also have a 90mm macro tamron and that one bf only a small amount if at all. This seems to be true of all cameras as far as I know, some like Canons have the issue in flourescent not tungsten. The AF still locks on like it normally would, the focus (after the shot) is just shifted back
How much is the focus off? At f2.8 and at what focusing distance? I know it's not off by much but I'm asking just to show marubex and others is not really a big problem.

And I remember reading you can cure this by using a filter which changes the tungsten color temp closer to daylight?

11-10-2010, 11:01 PM   #20
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Sigh. Tungsten causes problems all round. Just look at todays dpreview review of the Canon 60D. Same story.

My K-x however has no probs with tungsten and has generally excellent AWB. I expect the K-r will be just as good, if not better.
11-11-2010, 07:00 AM   #21
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The AWB is great but under tungsten and even a bit under flourescent there is a bit of BF with the tamron 17-50 most noticeable at 50mm, its like 1" below where you focus. The AF adjustment works pretty well but at 50mm its still a bit off. not that big of a deal unless you are shooting 2.8 in which case aim up I guess
11-11-2010, 07:05 AM   #22
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QuoteOriginally posted by rawr Quote
Sigh. Tungsten causes problems all round. Just look at todays dpreview review of the Canon 60D. Same story.

My K-x however has no probs with tungsten and has generally excellent AWB. I expect the K-r will be just as good, if not better.
I'd go so far as to say that the K-x was the first DSLR I've shot where the AWB in Tungsten light was particularly useful.
11-11-2010, 12:05 PM   #23
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QuoteOriginally posted by ovim Quote
I'm not disappointed coming from K200D (same sensor as K10D?), but I don't own the kit lens so I can't fully compare my results with yours. Could you post some pics?

Hi.
Yes, I will try to explain what I discovered through some pictures I`ll post here.
These two are both taken in "M"-program and the first was the exposure the camera wanted (1/40 seconds shutter). The second one I overexposed to get a more accurate and brighter picture... (1/25 sec)
Got many more examples but have to post this first in order to see if I uploaded correct.


Name:  Undereksponert 1-40sek.jpg
Views: 259
Size:  117.2 KB
Name:  Rett eksponert 1-25.jpg
Views: 261
Size:  125.6 KB

I've noticed a little underexposure too, but not as severe. If I shoot a uniform neutral grey surface the histogram is just slightly to the left. And in normal conditions (not shooting snow etc) depending on the scene I have to dial in max +1EV.



I have no issues with sharpness. My SMC-A 1.7/50mm is just as sharp wide open as usual. Are you comparing at 100%? Maybe your hitting the maximum resolution of the kit lens at f3.5 and it shows because of increased resolution? Or maybe your autofocus is off, have you tried the auto focus fine tuning? Also shooting under tungsten light might cause autofocus error?
Tried under many different lights and don`t actually need to look at 100% to see that the camera missed the focus.
I have tried the fine tuning (is the problem on new Dslr`s THAT big since these cameras got this "feature"?) but it just seems stupid to have to fine tune all the lenses just to forget which ones needs to be tuned up and which ones down....

It seems as the focus is ok now, but to me the "problem" I had looks related to the underexposuring... The focus is ok on correct exposures but when I try exposures decided by the camera`s metering; it`s off by some cm`s....
Wasn`t prepared to having to do all these adjustments in order to get correct exposures.
But now I`m at least aware of this and like I said in my first post, It`s hopefully easier now to get ok histograms and exposures.

11-11-2010, 12:21 PM   #24
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Few more examples:

1.
1/40 sec shutter, underexposed but the correct according to the camera`s metering.
Name:  Undereksponert 1-40.jpg
Views: 258
Size:  59.7 KB

1/10 sec shutter, overexposed but not so much. Actually also used +2.0 steps exposure compensation here. .
Name:  Rett eksponert 1-10.jpg
Views: 310
Size:  65.8 KB



2.
1/25 sec shutter, underexposed but the correct according to the camera`s metering.
Name:  Undereksponert 1-25 sek.jpg
Views: 257
Size:  233.5 KB
1/6 sec shutter, a bit overexposed background but I exaggerated here too by using +2.0 steps exposure compensation as well as using a slower shutter.
Name:  Rett eksponert 1-6 sek.jpg
Views: 315
Size:  256.8 KB

Both examples in "Av"mode.

Do you guys agree in my opinions or am I doing this all wrong?

Last edited by Larsenio; 11-11-2010 at 12:34 PM. Reason: Typo
11-12-2010, 08:38 AM   #25
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Yes, the images look underexposed but the "mug shot" and the "jeans" both have blown highlights in the background so it could be the camera was trying to preserve as much data as possible so it exposed like that to prevent the highlights from clipping? And maybe the plate shot has so much white in it it would need +EV anyway like shooting in the snow?

What happpens is you shoot a neutral scene which doesn't include any bright lights /or a lot of white?

I thought +2EV in Av mode lowers the shutter speed two stops (from 1/25 to 1/6)?
QuoteOriginally posted by Larsenio Quote
1/6 sec shutter, a bit overexposed background but I exaggerated here too by using +2.0 steps exposure compensation as well as using a slower shutter.

Both examples in "Av"mode.
11-12-2010, 09:09 PM   #26
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Hi, sorry for not thanking you before for your answers. Since i am new to all of this, could you help me understand a little better what the problem is? Right now I think i am confused thinking that the problem would result in a large amount of unfocused shots? Is it true and is there a way to fix it? What would you do if you were me? Would you still buy it?
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