Finally, a D300 Near UniWB JPEG

A Near UniWB JPEG for the D300 is finally available for download at

http://www.pochtar.com/Nikon_D300_NearUniWB.zip

Thank you gollywop for creating this file, and thanks to the Borgs for making it available.

farcus

just curious: what can i do with this file? It looks green. What is uniWB?
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Raymond Francois

I´m not sure myself how it works but found this thread using search.

http://forums.dpreview.com/forums/read.asp?forum=1021&message=22208265

lorange wrote:

I´m not sure myself how it works but found this thread using search.

http://forums.dpreview.com/forums/read.asp?forum=1021&message=22208265

Sounds to me it is important only if you use the color histograms a lot to adjust exposure. The color histogram reflects the distribution of each channel after the white balance is applied. The "UniWB" white balance setting will make the white balance a non-operation, that is, the pixel values are not adjusted by the white balance. I guess your preview will look off-color, but the net result is that the histograms will correspond much more closely to the distribution of color values in the raw data.

Very interesting, but I have to admit that I'm still too much of an amateur to pay a lot of attention to the histogram. For me the "blinkies" are good enough. There are a lot of other aspects of my technique I'll have to work on first :-).

Eric
--
http://www.lumenssolutions.com/photography/

UniWB provides a WB setting that allows the camera's color histograms to reflect far more accurately the exposure of each color channel. These histogram readings, therefore, allow one to assess exposure more correctly.

You would use it when shooting RAW (not JPEG) and would reestablish the correct WB for the shot during PP. The images taken with UniWB do indeed have a very greenish tint as displayed on the camera's LCD, but, of course, the RAW files themselves are not affected by the WB setting -- but the histograms are.

While this WB can be used at any time, its main value is when the scene is particularly lively in one or more color channels and one needs more accurate information to know the proper exposure to prevent clipping in those channels.

The purpose of the file to be downloaded at

http://www.pochtar.com/Nikon_D300_NearUniWB.zip

is to provide a JPEG file that allows D300 owners to establish the UniWB as a manual preset in a very convenient manner. The process for effecting this is explained on page 142 of the D300 manual. Essentially, you copy the downloaded image DSC0001 to the image folder on your CF memory card. This folder is located inside the DCIM folder and is named xxxND300, where the x's can vary. Restore the memory card to the camera and follow the instruction on page 142. You can copy the WB information from this JPEG into any of the four manual preset d1, d2, d3, or d4, and then use the chosen preset when you want to employ UniWB.

Note: if you already have a file named DSC0001 on your camera's CF card, you should change the name of the downloaded file to some DSCxxxx that does not conflict.

Thanks

Super catch, Ray; really nice.

We had decent weather today for the first time since I got the Near UniWB going, so I was out today knocking about with it as well. I just got through assessing the results, and I must say, I am impressed. I could push exposure in some instances further than I normally would have and still kept within bounds. But it is going to take some getting used to.

How far were you from this bird? I see you used flash and a 420mm lens. Interesting settings with a -1 EC and A priority. What leads you to these settings? They sure worked for you here.

nuthin here

Are you shooting JPEG or RAW? If the former, forget it; it's not really for your workflow. If the latter, adjust WB in your RAW converter. See prior post "A Brief Explanation".

oh yes

thanks a lot

kindest regards

I copied it to my camrera and will be playing around with it to get to know it.

jeminijosepth: This is explained above in this thread in the post labeled "A Brief Explanation." This WB helps set proper exposure, but basically assumes you are shooting RAW. You would then correct for WB in PP using a gray card or some such device. I should suspect that the WB adjustment that would be needed for JPEG would be problematic.

I guess in principle, when shooting JPEG, you could use UniWB to determine the proper exposure then switch to an appropriate WB before actually taking the shot. But this is going to be very awkward for everyday use -- maybe for special occasions when you have plenty of time to set up the shot and ETTR is very important.

So, basically, if you are shooting JPEG, whether or not with RAW, this is not likely to be of much use.