Cutting out glass on a white background?

[slazareth]

Anyone have any tips for cutting out glass that's on a white background to be placed on a colored background and have it look believable?

http://i.istockimg.com/file_thumbvie...iquid-gold.jpg

[John Wheeler]

Hi slazareth and welcome to the forums.

As always there are a variety of ways of doing this. If you are starting with a white background and want to change the background color through glass, this is very similar to just taking out some color from the white.

Apply a Photofilter Adjustment Layer of the color you want with the preserve luminosity turnoff. Adjust the density as you desire. On the adjustment Layer, Mask out anything that is opaque such as the cap to the medicine container. That should do the trick. If that is not what you want, just keep asking.

stock-photo-14376800-liquid-goldSWF.jpg

[slazareth]

Thanks! That seems to look okay, but when you try that with a color like blue it looks a little strange. The cap sticks out like a sore thumb and the glass+liquid don't feel quite right.

[John Wheeler]

I agree with you. I would be interested in what other members do in this situation. I you want to compare to believability, get a glass of water with some food coloring and put an alternate background other than white behind it. You may find that what is more realistic is not necessarily what you are looking for either because a different color background coming through yet another color liquid is just subtractive color science. Can come out pretty ugly. Do you have an example of the type of result you are trying to achieve?

[slazareth]

I do not. Right now its FPO for a design I'm working on so these are just tests. I will probably end up photographing the bottles myself on black so that this process will be easier. Ideally I'd photograph them on something close to the final color, but if I can't do that, black should be easier than white.

[Tony W]

I agree with John it is quite difficult (at least for me) to visualise the end result so a glass or bottle with coloured liquid and different backgrounds may help.

My example just used a gradient background masked the cap and the coloured liquid portion full strength and then a lighter grey mask for the clear bottle to background. Also a little shading around the bottle to highlight shape - I think I should have gone further around the bottle neck.

If this was real shot I would expect the yellow liquid to take on a green cast so could look unpleasant/unreal

[Chain]

Photgraphing on a background with a brightness close to what the new background will have should be best (but if you knew that early you could get a better result by photographic with the actual color behind it).

Changing from a clipped white background to a dark background is probably the hardest to do. Tony did a great job.

As it has been said, many ways to do this. The best might be to combine several techniques.

[Doug Nelson]

Try Chris Cox's white-to-transparent action that he demonstrated during one of his RetouchPRO LIVE shows

http://www.retouchpro.com/forums/ret...tml#post257184

[Heretic]

I think the trick is the have some shape in your color, not just a flat tint fading to the foreground, add some shading and detail to the edges and maybe where you think the horizon line is.

[slazareth]

Tony, great work! That's the best I've seen yet. And thanks Doug for the headsup on that action. Going to give it a shot now.

[Chain]

Made a serious attempt. I use a bit brighter background than last time to help it along.

I found the white>transparent action useful for the dark reflections in the glass, and the liquid/reflection.
For all the bright/white reflections (mainly the bottleneck) I manually masked it. There's not much information about those reflections in the photo as it is all clipped.

[daygraphics]

I agree that the Yellow liquid in the bottle would change color due to chosen color background. Also, Most studio shots of bottles with liquid will have numerous catchlights and some darker shadow edges. Best thing to do would be to shoot on a light neutral background which will allow you to isolate and enhance any catchlights or shadow modeling that will occur. I once shot a whole series of products and got the lighting and positioning just right - even before I had the stylists begin putting in liquid and food. I just kept duplicating the original shot and added the different product and "even" labels (as smart objects later).

http://www.daygraphics.net/CHERRY_MIXED_BUILD.gif