Luminous Landscape Forum
Equipment & Techniques => Lighting => Topic started by: Eric Kellerman on January 28, 2018, 07:56:54 am
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Here is a description of a problem I have quite regularly:
I shoot in the studio using Elinchrom lights (RXs mostly). Under the same lighting conditions, I can take two successive identical photos, one of which will have the colours I expect, while the other will have a not unattractive but unwanted golden sunset cast. This phenomenon is not camera-dependent: I get it with both my Canon and my Sony. In Camera Raw, the cast is more or less removed by selection of 'Auto' rather than 'As shot' in the White Balance menu.
As I only use Elinchrom lights, I am unable to say whether this is a specifically Elinchrom problem.
Can anyone tell me what is going on?
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One possibility is it could be that the capacitor has not reached a full charge before you fire it again for the next shot. Therefore the flash is not firing at full strength and dropping the color temp. a bit.
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Elinchrom lights (RXs mostly). Under the same lighting conditions, I can take two successive identical photos...
There are many different Elinchrom lights that have RX in their name from the budget D-Lite monoblocks to their top of the line power packs. RX refers to the incorporation of their radio receivers in the lights. So unfortunately you haven't really told us which lights you're using by your description. The less expensive lights, i.e. the D-Lites will have less color accuracy.
Also, how fast you're shooting and the power levels you're shooting at can make a difference in the lights ability to be consistent in exposure and color from shot to shot.
Successive identical photos taken at 2 seconds apart compared to successive identical photos taken 2 minutes apart could account for color shift and incorrect exposures.
So you need to give us more information please.
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My gut feeling is that the capacitor is not topped off like others suggested. Here's what I would try: Let it charge for a minute. Shoot a set-up image the shoot again as soon as it tops off, then a third at shot plus 10 seconds, 20 seconds... up to a minute then check the color between the different frames. This will tell you if there's a color skew in the power and perhaps the minimum time needed to charge up your particular unit to the proper level for each photo.
With my two Elinchrom 1100 w/s packs, they are both dead-on consistent at 5,000K but I usually am shooting no faster than 2-3 seconds per frame and seldom a full capacitor dump but that's for my two second-, perhaps third-hand unites and heads.
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Do you have the Beep turned on (button with musical note on it) and are you waiting for the beep?
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Thank you, everyone, for your helpful comments.
Bob Shaw and BrianBeauban: I have the beep turned on and wait for it to sound before taking the next photo.
langier: I have tried just what you suggest, but I do not see any relation between presence of colour cast and time between flashes.
Kirk_C: The lights are RX300s and BXRis. I am shooting at both full power and less, but power does not seem to be a factor. I am also a relatively slow shooter.
I can also reproduce the effect using both a wireless and a cable shutter release.
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Hi,
My are BX500. I do not experience your issue with those. Could it be that if you have your camera white balance set to AUTO, the camera gets occasionally fooled to 'see' a different white balance? When using my strobes, I set the WB to Flash.
Jean-Michel
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Could it be that if you have your camera white balance set to AUTO, the camera gets occasionally fooled to 'see' a different white balance? When using my strobes, I set the WB to Flash.
Jean-Michel
Thank you, Jean-Michel! I think you have the answer to my problem.
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Hi,
Let us all know if that is the cause for the inconsistent web.
Jean-Michel
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The lights are RX300s and BXRis. I am shooting at both full power and less, but power does not seem to be a factor. I am also a relatively slow shooter.
You're using the 'Style' line of monoblocks, marketed to the fashion, rapid fire shooter. They should be consistent within 100K color from shot to shot even when shooting fast.
Thank you, Jean-Michel! I think you have the answer to my problem.
If you're shooting RAW then just change the white balance to daylight or flash when you open the files. If that solves your color issue then you have your answer.
If not then test the lights individually by shooting a RAW file of a Macbeth color chart and check the color in PS or LR.
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One other thought... i seemed to remember one issue I've encountered occasionally... Shutter speed too slow for the ambient light. Check to make sure it's fast enough for your aperture setting to avoid capturing ambient light but not going above the fastest sync speed.
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If you're shooting RAW then just change the white balance to daylight or flash when you open the files. If that solves your color issue then you have your answer.
If not then test the lights individually by shooting a RAW file of a Macbeth color chart and check the color in PS or LR.
Thank you again, Kirk_C. Yes, I'm shooting RAW. Funnily enough, if I select Daylight or Flash as WB in Camera Raw, there is little or no change to the colour cast. If I choose Auto, things are considerably improved.
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Could it be that one exposure has the model light on the other off? Does the exposure time change between shots? Its feels like tungsten light is creeping in...
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I think my problem is solved. The 7riii apparently uses the modelling lights (tungsten in my case) to create the Auto White Balance, and not the actual light from the flash unit when the photo is taken. Choosing the Flash WB setting doesn't improve matters either.
The solution is to find the Custom White Balance setting in the menus, where the camera will ask you to point the camera at a white card, press the central button of the Rear Control Wheel, and all is then well, in theory.
And in practice, things are indeed much much better now.
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Does that differ from what you get by grey clicking on a grey card in your raw converter?
Cheers,
Bernard
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Does that differ from what you get by grey clicking on a grey card in your raw converter?
Cheers,
Bernard
After visual assessment and sampling with the dropper tool, I do not see a significant difference between the camera's Custom White Balance result and using a grey card.