Making selections easier

[chauncey]

You're shooting a subject that you intend to make a selection and insert that subject into another background...can I assume that using a highly contrasting background would be the best choice?

[Mike Buckley]

The only thing that matters is that the background complements the subject. A complementary background can be very similar or dissimilar, depending on the overall look you have in mind.

[Loose Canon]

Yes Chauncy.

You may assume that. Solid color BG. I like white but definitely contrasting.

Also if you are using Photoshop get a handle on the pen tool.

Best thing since sliced bread!

[NorthernFocus]

Contrasting and as little detail as possible and/or well blurred if possible.

[chauncey]

Was thinking of fly away hair on a black girl...was gonna use a white background.
I like using the threshold adjustment layer and the Color Range tool.

[Manfred M]

Hair is one of the toughest subjects to do successfully.

You need to get a shot where there is no cross-contamination from the background you are shooting. I prefer to have a background that is close in colour to the new one for hair, as it enhances getting a good blend when you move the subject. It is harder to make the selection, but the final result looks more realistic. I tend to use the pen tool for selections.

[chauncey]

Dumb idea...maybe? I shoot a lot of my water droplets using an image I've taken then displayed on my monitor. What might be the downside of doing the same thing with a big screen HD television?

[Manfred M]

Dumb idea...maybe? I shoot a lot of my water droplets using an image I've taken then displayed on my monitor. What might be the downside of doing the same thing with a big screen HD television?

Depends on the resolution and colour accuracy of your computer screen versus that of your television. TVs are generally not designed for great colour rendition, but rather being able to show motion images (thing fast sporting events), crisply without ghosting or artifacts. I know I would get bettter results using my computer screen than I would from any HD TV in the house.

[Colin Southern]

With fly-away hair (in particular), you need to keep a couple of things in mind;

1. Exposures are critical. If shooting a white background I normally aim to over-expose the background by around 1/3 of a stop - no more. Some folks advocate "nuking" the background by a couple of stops (sometimes it's what you have to do if you only have a crinkled sheet as a backdrop), but as the fine hair is effectively translucent, nuking it will blow the fine detail.

2. Accept that you'll ever get it perfect. Even with a green or blue screen, once you zoom in past a certain level, you'll get to a point where the anti-aliasing and demosaicing have produced a "no mans land" that's VERY difficult to extract data from automatically. All you can do at that point is quick/dirty local adjustments to move the image closer to what you're needing (eg de-saturating any remaining shades of green). Personally, I find that fine-tuning the background eraser tool gives me the best compromise when extracting from chromakeys.

Also if you are using Photoshop get a handle on the pen tool.

It's a great tool, but only of limited value in these situations; it's sublime for extracts of the clothing - can do well for skin (depending on lighting and how hairy the skin is) - for hair it's normally a pretty poor tool for fly-away ladies hair; better suited to short hair, although having just said that, often with fly-away hair you can "cheat" by just cutting it off -- and the curves functions of the pen tool can make that look good (keeping in mind that the viewer doesn't usually know how much has been trimmed, so it's possible to get quite aggressive.

At the end of the day, in Photoshop anyway, there are a bunch of tools that make extractions a lot easier - and I typically use a number of them on different parts of the image. Typically I'll pop a contrasting colour below the image layer - erase the bulk of the background with the eraser on the image layer, and then refine from there. There's only 3 zones - the bulk of the background which we can quickly bulk erase - the person, which we don't touch, and the transition area between the two - that where all the fun is. Typically I'll use the pen or background erase tools for skin and clothing and then more "manual" methods around the hair.

All in all, lighting makes extracts easy or hard; images shot with kicker lights are 1000 times easier to extract that ones where there's only key and fill lights, and the edges just "taper off into the darkness". Also, don't forget to use a drop-shadow when you've finished to avoid that "cut & pasted" look.

Hope this helps.