Halogen bulbs

akazoly · Apr 23, 2008

I use halogen reflectors (150Watt) for product photography. Yes I know, the color temperature is not white, but I think is not a big problem because White Ballance solve this issue.
I like to shoot on "Auto White Ballance" and RAW. But I want to ask a simple question. What I need to use in Camera Raw as white balance reference. For example is a good idea to shoot Auto and put a piece of black paper in light tent ? And use this black point in camera raw to correct white ballance?
I need ideas only for Auto (my situation), not Preset white ballance, please..

Thanks!

chinpokojed · Apr 23, 2008

I'm not sure what camera you're shooting with but most DSLRs will allow you to shoot a white card under your current lighting conditions, then set that as a custom white point on the camera.

Big Mike · Apr 23, 2008

One way would be to put something white into a shot. Then you can use that as a reference to set the WB for any shots with that same lighting. Apparently you can use a grey card as well.

Another way would be to set a custom WB on the camera. Your manual will explain how to do it...but usually you full the frame with something white, under the same lighting and take a shot. You can then go into the menu and set a custom WB using that shot. Then set your WB to 'custom'.

Helen B · Apr 23, 2008

Use something white, as Mike suggests, or light grey rather than black. Expanded polysyrene (Styrofoam) makes a very good, cheap white target.

Here is a link to an earlier post I made about materials for white balancing.

Something that ends up at a pixel value of around 200 is good - that is like the 'Neutral 8' patch on a Macbeth Colorchecker (the second patch from the left on the bottom row) - or expanded polystyrene which should end up at around 220.

Best,
Helen

Garbz · Apr 24, 2008

Any decent reference card you buy should include a black, white, and middle grey patch. Have your model hold it to get a reference white balance number.

akazoly · Apr 25, 2008

Hmmm. I have a strange problem, I don't know if white ballance issue. I take this photo using halogen light (2700 K):

The yellow is dark and not natural. I think this is not an exposure problem.

I shoot the same picture with 6400K fluorescent and the yellow color is much much better:

I put some money in halogen bulbs

Now I don't know what to do. I see the daylight fluorescent bulb is much better. Any idea how to solve this problem ?

Helen B · Apr 25, 2008

The colour (hue) is almost identical. The main difference is in the saturation and brightness.

I have a D40x, so I'll take some photos of a colour target in tungsten light and post an example. Ther should not be a problem.

Best,
Helen

akazoly · Apr 25, 2008

Helen what I need to do in your opinion to solve this halogen bulb issue? I need to adjust saturation ?

But how I know the hue brightness is similar like fluorescent?
Thanks much!

Garbz · Apr 25, 2008

Is it me or did you light those two shots from two entirely different angles. Yes the colours will be different if you do that.

JerryPH · Apr 25, 2008

Besides angle being different, intensity is as well. First one is a lot harsher light than the second one. You can see it becuase the top right edge of the paper is translucent in the top one, and not in the second.

We're comparing apples to oranges on too many different levels other than WB.

akazoly · Apr 26, 2008

The daylight bulb is much sharper (second photo). I use tracing paper at top with each light and each photo (first and second).

I don't know what is the problem but I think halogen is not for photography. Now I think how to build a flash trigger with some electronics and shoot with flashes (5500K).

I don't know what to do with halogen, I need to replace the tracing paper with cloth ?

Helen B · Apr 26, 2008

zoliky said:
Helen what I need to do in your opinion to solve this halogen bulb issue? I need to adjust saturation ?

But how I know the hue brightness is similar like fluorescent?

Is the tungsten shot lit from below - ie is it on a light table? I think that you problems are from the way it is lit, not from the type of lighting, or white balance. If you use the same light position as the fluorescent, your tungsten lamps will produce similar results if they are diffused.

I know that the two yellows are the same hue both by looking at them and by checking the HSL/HSB values. HSL is hue, saturation and lightness, while HSB is hue, saturation and brightness. The hue is the colour (ie red, yellow, blue etc) and it is measured as an angle in HSL. The hue angles of the two yellows are about the same (50-51 degrees).

There is a fairly high-end company that I know of that uses a D40x under tungsten lights (the modeling lights in the large flash softboxes) for product shots destined for the web. It is possible for that combination to work very well.

Best,
Helen.

Here's a very quick-and dirty side by side comparison, with only the saturation an brightness of the tungsten image changed: