Quicker way to seperate White shirts on white bkg

[ilegales]

i am retouching some kids who are wearing white shirts and shot on a white background

i want to make the whole background pure white 255.255.255 but still to keep the small shadows from their bodies /chairs

i am currently using the replace colour but wanted to know if theres a quicker way to achieve the same result

it usually takes me 20-45 mins to mask back the areas that were lost from the replace color

i select the eye dropper tool (first box) and change the color to pure white - i then hold shift and select on the photo the bkg and keep the hue 0, sat 0 and lightness 100 - which makes it pure white but also loses the white shirts /skin etc

maybe i am not doing it right but i dont know what else to use

i have a small photo with a step by step to show you my stages

like i say is there a quicker / easier way to get the same result as the final stage in the photo

many thanks

[Mike]

A quick but crude way is to use the Dodge tool set to white, be careful around the edges!

[dustbak]

It would have made your life much easier when you would have shot this the right way. Next time, light the background separately and give it more light so everything around your group just clips. Flag your background lights. Light your main subjects properly.

Maybe you are doing this for some else than there is nothing you can do about that.

You can also use levels and than mask the group with the blue channel. If you combine that with using the dodge tool you have more control.

[seattle-light]

Maintaining soft natural shadows while blowing out the background to pure white is a challenge on its own. Trying to do an overall adjustment that creates that pure white background while not affecting the shirts that are in the same tonal range. I don't see any way of doing this without at least masking the shirts. And I'd watch really carefully for banding in those underlying soft shadows. In the retouched versions, I would maintain the values in the original shot for the white shirts or brighten them only slightly. In both of the versions you've shown the brightened white shirts are blending right into the background. You need to have some tonal separation between the white shirts and the white background, and you need the tonal range in the shirts to help establish the texture of the shirts and form of the subjects. You're losing shoulders and arms into the background. Brighter isn't always better. In both of your retouched versions, it seems to me that you're also losing all of the interesting shadow detail on the floor in order to achieve that pure white background in one adjustment (you're going to have to treat different parts of the background differently. Sometimes it's better to extend a very light tone for the entire background of an image. Pure white can look really artificial. Is there a particular reason for the pure white?

[ilegales]

Originally Posted by dustbak

It would have made your life much easier when you would have shot this the right way. Next time, light the background separately and give it more light so everything around your group just clips. Flag your background lights. Light your main subjects properly.

Maybe you are doing this for some else than there is nothing you can do about that.

You can also use levels and than mask the group with the blue channel. If you combine that with using the dodge tool you have more control.

Thanks so much for the lighting advise - your absolutely right if i had made the f-stop 1 or 1.5 over my main than i would have a better seperation - i guess i did not want to get any bleed from the bkg light which were flagged but still you have slight bounce from the other areas of the celing or paper -

anyway i will adjust it better next time -

You can also use levels and than mask the group with the blue channel. If you combine that with using the dodge tool you have more control.

could you please explain that in a more step by step way as i am not sure how to do it

many thanks

[ilegales]

Originally Posted by seattle-light

Maintaining soft natural shadows while blowing out the background to pure white is a challenge on its own. Trying to do an overall adjustment that creates that pure white background while not affecting the shirts that are in the same tonal range. I don't see any way of doing this without at least masking the shirts. And I'd watch really carefully for banding in those underlying soft shadows. In the retouched versions, I would maintain the values in the original shot for the white shirts or brighten them only slightly. In both of the versions you've shown the brightened white shirts are blending right into the background. You need to have some tonal separation between the white shirts and the white background, and you need the tonal range in the shirts to help establish the texture of the shirts and form of the subjects. You're losing shoulders and arms into the background. Brighter isn't always better. In both of your retouched versions, it seems to me that you're also losing all of the interesting shadow detail on the floor in order to achieve that pure white background in one adjustment (you're going to have to treat different parts of the background differently. Sometimes it's better to extend a very light tone for the entire background of an image. Pure white can look really artificial. Is there a particular reason for the pure white?

thanks for your very informed responce -

the reason why the end shot is quite a bit lighter thus some arms get lost is that my printer will darken it +1 which will make it much richer - i do print these as they are a group shot and it looks ok in print
the reason for pure white is that its for a group shot of kids and i want the focus on the kids who may be seated or on stools etc so white is good for that focus but the school has white shirts etc so maybe i will have them wear their navy jumpers next time -

[dustbak]

When it is for print, you definitely do not need the pure white! For web usage often you do.

I shoot on white very very often and key to preventing your background giving back light is to shoot it just above clipping and keeping as much distance as possible.

For the procedure to get it to white.

0) Make a rough selection around your group, reverse selection and fill with white.
1) Make a levels adjustment layer. Pick the darkest point you want to have white as white.
2) turn off this layer.
3) Go to the channels palet, select the blue channel (which is often the darkest channel with most contrast). Copy it into a new channel. Use levels to make the dark black and the (almost) white white. Turn this into a selection.
4) Turn on the levels layer
5) Create a mask while having your selection on. This should create a mask that protects your group from your levels adjustment. (It might happen you have to invert the mask).
6) Back off the levels adj. layer
7) Fine-tune with dodge on you background layer

After this you can fine-tune some more with the levels layer. Naturally there are a lot more ways of doing this but this one works pretty well and fast.

[jerome65]

As a book designer in educational publishing I have done a lot of similar images. The basic way that I would tackle it would be to isolate the kids on a separate layer with a mask, pick your favorite way to mask them out. This allows you to adjust the shadows separately. I would probably make a layer with the top masked out and a soft "horizon" line a the floor and a fade to white at the bottom. Paint out a fade to the left and right. Use an adjustment layer to desaturate the shadows and adjust the opacity of the shadow layer. Then group a selective color adjustment layer with kids and add in a bit of tone to the whites, something like 5-7 cyan, and 2-3 in magenta, yellow, and black so that the "white" of the shirt has a bit of tone to it.