[bsamcash]

To my knowledge FIRMWARE is the only way to fix this. Sending your camera for calibration is just going to result in disappointment.

Are you sure about that? I sent mine in for repair and asked for a calibration with my favorite lens as well. They seemed confident.

[krebsy75]

The following is complete speculation. Read at your own risk:

To my knowledge a global focus adjustment is all that is possible from a service center. Perhaps someone with more expertise can chime in.

It's definitely not as simple as adjusting focus for one or more white balance presets. I think the whole white balance theory has been taken out of proportion. It's possible the camera is programmed to adjust focus accordingly when the reflected source light is measured to be within the low end of the spectrum (via custom or AWB). It's also possible that improved focus results can be obtained by manually selecting the closest white balance preset. Understand that custom white balance is the most accurate method for determining the color temperature of the reflected source light.

This is a software or hardware flaw and not a calibration issue (the way I see it). Software bugs and/or missing features can sometimes be resolved with revised firmware.

Are you sure about that? I sent mine in for repair and asked for a calibration with my favorite lens as well. They seemed confident.

[djb21au]

Based on my experience in use, as opposed to tests, I think it's a low light issue. Last night I was taking handheld street photos at night - the camera is brilliant for this, btw - and had to focus manually to get the best results. Similarly in a cave a week ago. In both cases the available light wasn't just tungsten. The macro theory sounds interesting to me: might try some tonight with one of the scene settings and see if it makes a difference.

[djb21au]

One nagging question I have is that if it is a firmware issue, why do a lot of people report no problem? For me it is an issue with the kit lens as well as the f1.4, so it's not just a wide aperture issue. Interested to hear how the OP's repair goes.

[krebsy75]

Those who report no issue are not using a fast lens like the FA 50 f/1.4 in tungsten lighting without a flash. I can guarantee that.

One nagging question I have is that if it is a firmware issue, why do a lot of people report no problem? For me it is an issue with the kit lens as well as the f1.4, so it's not just a wide aperture issue. Interested to hear how the OP's repair goes.

[djb21au]

For the record:

I've just been outside in low light testing MF v AF and in various settings MF always won. (I was using the kit 18-55mm this time). Not highly scientific but I tried the Night Snap scene setting, Av with AWB, Av with Tungsten WB (shooting tungsten lit subject) and Av with Daylight WB (same subject). MF always notably sharper. The results are simply more pronounced when using the 50mm 1.4. One thing I forgot to do was try Live View.

Sorry - not in a position to post the actual shots at the moment. Bottom line, with my camera at least, an FF issue does exist in low light.

I haven't been able to upgrade the firmware yet to compare, and I reiterate that this issue has not affected the vast majority of my over 4000 shots taken in the last month and a bit. Any form of daylight: no problem at all.

[krebsy75]

When you selected Daylight WB what was the source light?

For the record:

I've just been outside in low light testing MF v AF and in various settings MF always won. (I was using the kit 18-55mm this time). Not highly scientific but I tried the Night Snap scene setting, Av with AWB, Av with Tungsten WB (shooting tungsten lit subject) and Av with Daylight WB (same subject). MF always notably sharper. The results are simply more pronounced when using the 50mm 1.4. One thing I forgot to do was try Live View.

Sorry - not in a position to post the actual shots at the moment. Bottom line, with my camera at least, an FF issue does exist in low light.

I haven't been able to upgrade the firmware yet to compare, and I reiterate that this issue has not affected the vast majority of my over 4000 shots taken in the last month and a bit. Any form of daylight: no problem at all.

[rfg]

Yes, I've checked the AF in both daylight and with other light sources (pitch black such that the AF assist light is the only light), and the focus is fine. I'm sending the body in tomorrow and will let you know how it went when I get it back.

Just repeated my test in daylight, using both auto and daylight WB. Focus is fine: just as sharp as live view, so one more vote for tungsten light as the problem. All these shots report "Close View", not macro (same distance and 32.5mm f4 lens setting as before).

I tried all the auto focus settings: interestingly "spot" was worst: still focused but a touch softer than the others.

[jcespite]

I tested my kr with my fa43 at f2 1/100 sec at 1600 iso indoors and with AWB or not; I had front-focusing issue. With LiveView everything is sharp and no front-focusing. My camera has an earlier 37*** serial number so maybe they have address with the new production run.

[EricT]

Just repeated my test in daylight, using both auto and daylight WB. Focus is fine: just as sharp as live view, so one more vote for tungsten light as the problem. All these shots report "Close View", not macro (same distance and 32.5mm f4 lens setting as before).

I tried all the auto focus settings: interestingly "spot" was worst: still focused but a touch softer than the others.

Thanks, it seems that many people are seeing this in tungsten light. I've sent my camera in now, will be interesting to see if they are able to fix it.

[manninej]

I also bought a K-r just last week and I'm also scanning these threads to see what others have found out. Here's my own test shots, where I used candle light as I will be doing that kind of shots few times a year. But this is what I see currently:



Quite interesting what happens to the WTB with the help light, and also for the FF. Shots taken with DA 35mm open at 2.4 using tripod and Av program.

[ramones1985]

I also bought a K-r just last week and I'm also scanning these threads to see what others have found out. Here's my own test shots, where I used candle light as I will be doing that kind of shots few times a year. But this is what I see currently:



Quite interesting what happens to the WTB with the help light, and also for the FF. Shots taken with DA 35mm open at 2.4 using tripod and Av program.

In "Room Light + 3 Candles" there isn't FF ...or is very small.

the problem is with low light....

[manninej]

Well, it is correct in the first image on left only after adjusting to Tungsten WTB and maximum AF correction of -10. Room lights are 2400K and about say 100W together.

Other thing that I noticed is that if I shoot using 11 point auto focus it selects the point where the focus is when shooting with spot focus. I don't know that much about AF systems, but shouldn't automatic focus point select the black bar (in the chart) instead of white area?

[ramones1985]

F 5.6
T: 0.8 sec
f=18mm
iso:100
No AF correction.
lens: 18-55
Camera on the table (not on a tripod)



In this photo there is FF?

[alffastar]

Guys, I bought pentax k-r along with limiteds 15, 21, 40 and 70. Do not even ask me what nightmares and happy moments this whole decissin caused me!!! However, now I hav em all and it is a done deal. I am from Bulgaria, and a friend brought all this to me from the States. The price difference of the limiteds is huge, however I made a mistake buying the K-r without a warranty! It had two problems - first the e-dial did not work and from the first moment did not focus correctly in artificial light! I had to fix the e-dial and now my K-r is in for calibration with my 70 2.4 limited.
Firstly, it turned out you could make calibration based on different conditions, and that is on the physical temperature (not color, but the temperature of the sensor in K or Celsius degrees) of the ccd focusing sensor. So the guy calibrated the K-r for different temperatures!
Secondly, however, he said the focusing in low light is still no good and he cannot fix it here and I have to send it to pentax Germany, 150 Eur only for transport and checking what the problem is!!!!
I cannot pay that now, so tomorrow I will take the K-r with me and check for myself what the improvements in focus are and will report back here.
So, 2 things are clear: 1. You can calibrate the focus for different temperatures; 2. I think this focusing issue is not software, otherwise it would be inhumane to ask for 150 EUR for hardware check when a known firmware issue exists.
Cheers!