| Author | Thread |
|
|
08/08/2004 04:23:49 PM · #1 |
I am working on setting up a lighting system at home. The main objective is to get control of my WB problem. It seems that no matter what I use to light the object with, the WB is always off by some degree.
My camera has 5 settings; auto, daylight, cloudy, incandescent or fluorescent. There is no manual mode, and no RAW capability to be able to adjust it later. It seeems no matter what lighting I work under, there is always some tint to the image. When using my halogen worklamps the fluorescent mode works best, but is still slightly off. I was searching around the net for lightings suggestions and found a thread on iPhotoForum that suggested that with halogen lighting to set the WB to fluorescent and then 'muck around with the EV setting'.
My understanding of the EV setting is that it simply adjusts what tone the sensor is trying to set the subject it is metering at. For example, with the EV set at 0, whatever I point at will be metered as if it was neutral 18% grey, but if I want that to be metered for 1 1/3 stops above neutral grey I adjust the EV by 1 1/3 stops and set accordingly, but if I want it to be metered for 2 stops below neutral gey I would set the EV setting to 2 stops in the opposite direction.
If my above understanding of the function of the EV settings is accurate, what does this have to do with WB?
I generally prefer to set the WB to one of the presets, rather than use Auto. When in auto, the metering also sets the WB and unless I use a grey-card, the image will be tinted by the auto-WB attempting to compensate for the color of what I am metering. While this is useful to use as cheap color filters, it is very annoying any other time.
David
|
|
|
|
08/08/2004 04:54:15 PM · #2 |
I think your understanding is correct. EV should not have anything to do with WB.
Although I have noticed on my camera, when in manual exposure mode and using settings that overexpose the image, the camera is unable to set proper WB. So maybe setting a high EV plus or minus does influence WB. Questions is whether it does it in a predictable way so you can use it.
|
|
|
|
08/08/2004 06:18:46 PM · #3 |
I'll have to try on one of my preses and check, but I have mixed my halogens and Reveal bulbs, but I calibrate.
Just gave it a shot and Incandescent comes out the best with Reveal and Halogen. Just a little faint coolness to it.
|
|
|
|
08/08/2004 06:21:40 PM · #4 |
I wonder if they meant the WB fine tuning setting, instead of EV, because it often looks similar to an EV value (+1, -1, etc.) and is sometimes adjusted with the same controls.
The is most commonly useful with fluorescent lights. They come in 'cool white', 'warm white', and various color temperatures. Cool white is I think the most common, but the point is that most cameras have a choice for +1, -1 color temperature to set for different fluorescent bulb types. My little Nikon Coolpix has this as does my D70. |
|
|
|
08/08/2004 06:26:04 PM · #5 |
Oh, also it is possible to adjust the white balance even from the JPEGs, it's just not quite as simple or accurate as from RAW or in-camera, but it may be just what you need. Here are some links:
//www.dpreview.com/learn/?/Image_Techniques/Color_Correction_Speed_01.htm
//www.bairarteditions.com/pages/tutorials/photoshop/colorbalance.html
Hopefully that can help you get the right balance. If there's no pure white/gray/neutral tones in the image, you can take a picture of a white or gray card under the same lighting conditions, and help use that to adjust the levels in Photoshop. |
|
|
|
08/08/2004 06:35:58 PM · #6 |
I just got the book Adobe Photoshop CS-The Art of Photographing Women (excellent so far). Have learned a few great things already.
I am going to get a white/grey/black card (already have a grey).
I recommend this book for sure!! It goes through this very problem, that is possible even without the card, but a little tougher. It involves setting up three points with the color sampler, open the info box. Adjusting the white and black point to be ~249 and ~28 (or what works for the photo). You want all the numbers to match-ie:245, 245, 245 or 28, 28, 28, by adjusting the different color levels up or down. Then going into curves and doing it for the grey point. A little involved to type it all here.
|
|
|
|
08/09/2004 04:25:38 AM · #7 |
Thanks for the comments and suggestions.
I know how to correct the white-balance (with mixed results) due to a start along that track from moodville's tutorial on 'Removing a Color Cast'. I just prefer to not have to do any more in post-processing than I have to.
It is beginning to look like I have run into yet another limitation of my camera I have to learn to work around. :(
Anyone know a good place to buy a white-grey-black card? I've seen them before, but have been trying to get by with the grey lens cleaning cloth I have. It is too reflective though, doesn't produce a solid tone to meter.
David
|
|
|
|
08/09/2004 09:09:09 AM · #8 |
Check out the WhiBal product. I've been eyeing a set for a while. Unfortunately they are on backorder because of their popularity (they just came out a couple months ago).
You may want to download a demo version of ColorWasher and see if it makes any difference adjusting the WB in your photos.
Also, if you have Photoshop CS, choose Image > Adjustments > Match Color... and click the "Neutralize" checkbox. Does an amazing job correcting 99% of your color problems that easily. =] |
|
Home -
Challenges -
Community -
League -
Photos -
Cameras -
Lenses -
Learn -
Help -
Terms of Use -
Privacy -
Top ^
DPChallenge, and website content and design, Copyright © 2001-2025 Challenging Technologies, LLC.
All digital photo copyrights belong to the photographers and may not be used without permission.
Current Server Time: 09/17/2025 05:36:36 PM EDT.
