D-I-Y ChromaKey macro...?

[RokcetScientist]

The discussion about 'GreenScreens' in the other thread Green Screen Frame? made me think that, if I could recreate ChromaKey backgrounds with a printer, I would have ChromaKey capability for macro shots! That could be very interesting to experiment with! I see a whole realm of possibilities opening up...
Of course you would need to know the precise RGB and/or CMYK code!

Does anyone here have any ideas about this? Has it been done before? Would it work?

[Mike]

I have Primate Chromakey from Digital Anarchey. As I understand it, one can use any color for the background AS LONG AS THAT COLOR DOES NOT APPEAR IN THE IMAGE THAT YOU WANT TO SAVE.

So look at the subject you want to use, pick a color that does not appear there and use that for the background.

Green is used for people because most people do not have too much green in their skin or hair. Other than that there is no reason to use any specific color for the background.

[Cameraken]

Hi RokcetScientist.

Interesting Idea. But probably not the best method for macro. The reason is that usually the whole subject is shown in a macro shot.

Let’s say you were photographing a flower with a ring flash.
If the flower were placed on chroma background then the light from the ring flash would quickly fall off giving uneven lighting (and a difficult mask). It is very difficult to add more flashguns to balance the light. This is why most photographers would use a light tent or light box. Please read this thread.
http://www.retouchpro.com/forums/photo-restoration/11621-please-help-glare.html

There is another way.
One method that works really well is to use a scanner.
A scanner will scan anything. It does not have to be flat.
The attached photo was scanned on my scanner. Just place the item on the glass and cover with black fabric to avoid stray light.
If you want to scan snails and worms then use a layer of cling film.


Ken

[maureeno]

Originally Posted by Cameraken

Hi RokcetScientist.

Interesting Idea. But probably not the best method for macro. The reason is that usually the whole subject is shown in a macro shot.

Let’s say you were photographing a flower with a ring flash.
If the flower were placed on chroma background then the light from the ring flash would quickly fall off giving uneven lighting (and a difficult mask). It is very difficult to add more flashguns to balance the light. This is why most photographers would use a light tent or light box. Please read this thread.
http://www.retouchpro.com/forums/showthread.php?t=11621

There is another way.
One method that works really well is to use a scanner.
A scanner will scan anything. It does not have to be flat.
The attached photo was scanned on my scanner. Just place the item on the glass and cover with black fabric to avoid stray light.
If you want to scan snails and worms then use a layer of cling film.


Ken

So Ken, did you place the flower ITSELF on the scanner bed, cover with the black cloth and then scan? What a brilliant thought!!

Maureen

[RokcetScientist]

That's very interesting, Mike. That way, you can plan and preshoot your macro scene, analyze the colors, determine the one least present, print a ChromaKey background in that color, and do the 'real' shoot. Resulting in a near friggin' perfect ChromaKey effect. Which you could then complete and enhance in PP.

Still wouldn't mind knowing the exact RGB/CMYK numbers of the standard blue and green that the experts use. They aren't using them for nothing.

––––––––––––––––––––

Originally Posted by Cameraken

Hi RokcetScientist.

Interesting Idea. But probably not the best method for macro. The reason is that usually the whole subject is shown in a macro shot.

Let’s say you were photographing a flower with a ring flash.
If the flower were placed on chroma background then the light from the ring flash would quickly fall off giving uneven lighting (and a difficult mask). It is very difficult to add more flashguns to balance the light. This is why most photographers would use a light tent or light box. Please read this thread.
http://www.retouchpro.com/forums/showthread.php?t=11621

Thanks for your insight and that link, Cameraken.
I don't have/use a ring flash (yet?), but I do have some experience with multiple off-camera flashgun, reflector and 'light tent' setups for commercial portraits and insurance photography (art & antiques collections). That'll keep me going for a bit. For now, I can do it with a combination of low power flashguns and a light tent, or, more realistically, barndoors/snoots and reflection. To create a lighting that merges with the light that is in the 'background photo' that the macro shot will be PP'd into.

There is another way.
One method that works really well is to use a scanner.
A scanner will scan anything. It does not have to be flat.
The attached photo was scanned on my scanner. Just place the item on the glass and cover with black fabric to avoid stray light.
If you want to scan snails and worms then use a layer of cling film.

Ken

Isn't the DoF less than 10 mm (0,4")?

[Cameraken]

Hi RokcetScientist.

Isn't the DoF less than 10 mm (0,4")?

I don’t have the figures but DoF (Depth of Field) is limited. But it is also very limited with a good SLR and extension tubes.

It may be possible to increase DoF by using ViewScan software which has a focus adjust (I’ve never tried this)
Also it may be possible to cover the subject with something reflective rather than black material to increase the light.

There are loads of pictures on the web using this method. An example here.

http://www.abstractconcreteworks.com...daffodils.html
and here
http://www.abstractconcreteworks.com...ll-life-1.html

You would need an expensive camera to improve on these results.

Ken.

[RokcetScientist]

Originally Posted by Cameraken

Hi RokcetScientist.

I don’t have the figures but DoF (Depth of Field) is limited. But it is also very limited with a good SLR and extension tubes.

But with a good cam, lens, extension tube(s) or bellows I still have some latitude in settings. Which I don't if I'm scanning a subject.

It may be possible to increase DoF by using ViewScan software which has a focus adjust (I’ve never tried this)
Also it may be possible to cover the subject with something reflective rather than black material to increase the light.

There are loads of pictures on the web using this method. An example here.

http://www.abstractconcreteworks.com...daffodils.html
and here
http://www.abstractconcreteworks.com...ll-life-1.html

Anyway, this "macro scanning" is really off-topic, because this thread is about combining chromakey technique with macro.

You would need an expensive camera to improve on these results.

Which, for now, is in itself an excellent reason not to pursue this avenue much further... And very far removed from "D-I-Y", imo.

[Cameraken]

RokcetScientist.

Apologies for my digression.

Chris Hoggy describes how to make a home made macro lens here
http://www.retouchpro.com/forums/photography/13548-stock-xchng-images-accepted.html

Hope this helps.

Ken.