Jump to content

Model Photo Colour Balancing With A Swatchboard


MojoBob
 Share

Recommended Posts

I've been experimenting for a while with using a colour and tone swatch card in an attempt to get more reliable colour balancing and exposure with the automated controls of my camera.

It can only help so much with strongly coloured backgrounds though; you can see (below) that there's considerable colour contamination from the green background, but that's due to reflection, not the camera's own colour handling.

Having a mathematically delineated tone card within the scene helps the camera's automatics, but it's also very useful for post-processing, as it gives you a concrete reference to perform exposure and colour balance adjustments to.

 

AVvXsEh27Ddf0gWZx-rY8bMR9XWIr7wu1jaf0N8p

AVvXsEhOaspUZ-sdrHSZul5L6wq1vQy4a5t-2VJi

 

Of all of them, it seems to be most successful with a black background, though the white background is fine as far as colour goes — it just overwhelms the tones of the model itself. The model on the black background would be more successful still if I used a reflector to get some light into its shadows, and it could do with a touch more exposure too; you can see the greyness of the white swatch compared with that on the white background.

 

AVvXsEh81-Vw1jX4QG6Aorc5Vdu2l6TPytGnwfdr

AVvXsEi5ok3EfyuAdCFWLKGZGxAQBV5ZdmY8tqPo

 

Of the two with the green background, the one with the swatch card in frame is the more accurate colour-wise, though again it could do with a little more exposure. In the other one the camera has blown out the background quite substantially to expose the model better.

In retrospect, I probably should have framed the last photo with the same model/frame ratio as the others, just without the swatchboard. I think it would have given me a more accurate result. But never mind.

 

The swatch card I've used is just something that I printed on my cheap laser printer, though I've painted over the black and white swatches to get them as clean as possible. You can buy similar cards, properly calibrated for studio photography, but they're not cheap, and all you really need is something close enough. As long as you have a repeatable reference colour/tone set to match against, you have a baseline constant to work from.

  • Like 4
Link to comment
Share on other sites

  • Replies 4
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

I've only used white balance grey cards for some basic calibration. The professional colored checkerboard are kind of overkill for our needs.

 

Since I also own several of the old Hangar 18 photo backdrops of various colors, I switch backgrounds until I find one that goes well with whatever I painted. And occasionally I play with the lighting itself. Either with my ReaperCon light box, my hobby lamps, natural daylight, mix-and-match.

  • Like 2
Link to comment
Share on other sites

The card you're showing is an excellent idea for white balance in your raw editor. Most of the time your camera itself won't consider it for adjusting the photo but once you load the picture into Lightroom, Cannon DPP, and any other RAW editor you can use your 'spot white balance' tool to pick a spot in the frame that should be pure white and balance the colors so that it is.

if you're using a cell phone camera or JPEG only camera, Photoshop and Gimp have a version of the tool too, they're just more effective when you can use them on RAW images.

 

As for auto exposure, the card could help a little but given how camera exposure meters work it's tricky.  A 50% grey swatch to hit with spot metering would be best, but if you're just shooting with the card in frame most cameras are still going to use either the old dumb average metering or a center weighted average, which weights the center 15% or so of the frame.  Partial metering would actually ignore stuff outside that 15%, and Spot metering tightens it down to about 5% of the frame right on your focus point.  If you can use Spot metering on a 50% gray swatch, then lock in the exposure (using manual settings) focus over on your model, that would be helpful. I find that for general exposure, simply spot metering right on the model usually is sufficient, but you have to get away from Average, Center Weighted Average, Matrix, Evaluative, or whatever other metering modes the camera wants to use for miniature photography or your background probably will drown or blow out your model.

 

Alternately, if your camera supports exposure bracketing, you can set a range, say 2/3 of a stop, and take 3 pictures in succession, it will take one at what the meter says, and then one each up and down that 2/3 of a stop in exposure, and then you can pick the best one.

Edited by Cygnwulf
Link to comment
Share on other sites

ALL that being said, the auto white balance tool is usually also accompanied by an auto exposure feature (at least in a raw editor) where you can adjust the exposure up to about half a stop as well, so you could use your swatch card during your adjustments to set your white point and black point, then the others could be used to tune curves

Link to comment
Share on other sites

Just for grins I downloaded your three images into GIMP and played with them some.  I was able to do some with the exposures, though the black one was still a little over exposed and the white one a little under.
What I did was open the 'levels' tool in GIMP and set the black point and white point off your card (I actually used the card holder for the black and green because using the card itself resulted in a very dark image since the card is more of a dark grey)

They're closer together, though the white background is a little under exposed, making the adjustments give us some weird output.  The black isn't bad, though the shadows are still very dark because there's not much reflected light from the bottom.  The green actually looks pretty good, a good amount of reflected light combined with a pretty even exposure, even though the reflected light gives it a green cast.  It might be possible to adjust some of that out with curves but that would be some manual work to do in GIMP that I'm not very good at, it would be easier done in RAW if possible.  

swatchwhite.jpg.d03b3cd22df5b079c502d1c1de56dcb4.jpgswatchblack.jpg.a93f9d0a4eed6ee570173179e53b80ac.jpgswatchgreen.jpg.58e5f4adc6ff3f07eefb131d88e16d72.jpg

All of this has put me in mind to try to come up with some medium neutral backgrounds to take pictures against.....

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...