[lotech]

Hi there,

I find the AW is quite off on the K3 especially in extreme low light, whenever I shoot above ISO 6400 under tungsten light the image will become very yellowish, I tried all settings about AW but still can't get it right, then later I realized that there are actually two AW modes, the one I think is matrix AW can fix that, I can get prefect balanced image most of the time, but still randomly the image turns reddish but the next shot the same scene turns out right I don't know why, any idea ?

[Adam]

Hi there,

I find the AW is quite off on the K3 especially in extreme low light, whenever I shoot above ISO 6400 under tungsten light the image will become very yellowish, I tried all settings about AW but still can't get it right, then later I realized that there are actually two AW modes, the one I think is matrix AW can fix that, I can get prefect balanced image most of the time, but still randomly the image turns reddish but the next shot the same scene turns out right I don't know why, any idea ?

It's not really the AWB's fault, just the fact that dynamic range and color accuracy is significantly impacted at high ISOs. My recommendation would be to shoot in RAW and make manual corrections as needed.

Multi-segment AWB wouldn't be of any help in this case.

If you'd like, post a sample and we'll take a look.

[lotech]

Thanks for the advice, I shoot JPG mostly I know RAW can do lot more, I don't have a pic to post at this moment, imagine you shoot with a deep red filter you will know...

[stevebrot]

I know RAW can do lot more

Yep! In RAW you can choose whatever white balance you want in post. It is not set in stone.


Steve

[wizofoz]

Agree about shooting in raw. If you can't then at the very least take a shot of something white or grey to reference in post.
I find the multi segment AWB to be almost flawless. In fact I'm surprised that Pentax don't make more of a fuss about it. I think it is an industry leader.

[rawr]

dynamic range and color accuracy is significantly impacted at high ISOs

This, very much so.

But given those practical limitations, I've shot K-3 in very low light and extreme ISO and don't really have any AWB problems to report.

The random variability in your light colour may have something to do with the frequency of your local power supply, and/or the exact type of incandescent light source used (sodium-mercury vapor?, tungsten filament bulb?. halogen?) - either solely, or mixed with other light sources. Each may contribute something to colour temperature flicker.

For instance, using a Nikon, I shot a night rodeo under stadium lighting a while ago which was using several sets of sodium-mercury vapor lamps [I think]. While they had no perceptible flicker, I was perturbed to see on image review that even when shooting image bursts, each 6fps shot had a different colour temperature. Luckily, RAW is very good at letting you set your AWB after the fact.

---------- Post added 2015-08-04 at 03:36 PM ----------

Oh, and of course if you are using a polarizing or UV filter on your lens, strange exposure problems in low light may also be related to that too. Low light and filters of any sort do not mix, due to the internal reflections, colour casts, polarization, coma and other aberrations such filters may introduce.

[rvannatta]

Thanks for the advice, I shoot JPG mostly I know RAW can do lot more, I don't have a pic to post at this moment, imagine you shoot with a deep red filter you will know...

I've got 2 k-3's and tend to use high ISO and AWB. Both of them behave similarly with the WB as displayed on the camera monitor bouncing from one color balance extreme to another. when I first saw it I was horrified but then noticed that it only visually appeared for me when I view the work
on the camera. I shoot in both RAW and Jpg f(1 on each card), but I download the RAW, and never look at the JPG as it's a backup,
with photo shop, and the problem literally disappears during the downloading to photo shop sequence. -- when the photos arrive in Photoshop
organizer before they are touched by human hands they are perfect in color balance.

I have the original k3 software and have never upgraded... I have wondered if it was a software bug that perhaps made a fix list
but it doesn't annoy me enough for me to upgrade the K3 firmware.

[lavascript]

Custom WB ftw.

When shooting candids in my lamp-lit living room at ISO3200, my K-3's AWB blows my K-r out of the water. Which blew my K10D out of the water... But while it's much better, it's still not great. Fortunately, the K-3 has three slots for Custom WB. Set one for your house and be done.