Very Sexy 3 color DCG

[Johnfp]

Well, I will say....oh, never mind...lol

I think that may be the source of the confusion. A colour picture of any kind implies a reproduction of the colours in the original to the colours in the reproduction. So, if I take a picture of a grass-covered lawn, I assume that the photograph of the grass covered lawn looks pretty similar to the real grass covered lawn. However, if I wish to translate the green of the grass into a blue grass (for whatever surreal reason) then I might effect such a change by some choice of dye that translates a green image into a blue one. In this case, I'm also taking a colour picture with my camera, but the camera has imbued in it an additional function of colour translation. However, if were to lend my camera to someone and he/she were to take a picture of his/her lawn, she might complain that the green grass became blue in the final picture. The argument that it's still a colour piccture is, of course, valid, but the miscommunication arises because of the interpretation of the words "colour picture".

Sort of, but in your case you are making what everyone knows as green grass and making it blue, this would raise some eyebrows. Ad that is exactly what I was talking about in using colors that people are familliar with. Yellow hair is reasonable. Green wrap is reasonable. Light orangish for skin is reasonable, and orange for dress is reasonable. Its a believable hologram color wise. Let's say your camera malfuncioned and would not record green at all and you had to show "green" grass to a class for learning purposes. You shurely wouldn't bring in the blue grass. You may take the picture and in photoshop, fix it to be green, the color everyone is familiar with and you want to teach correctly.

Now, with a film dumb to red, DCG, doing some type of human model poses some problems. You could do a single exposure and change the processing such that she is blue, green or even the whole hologram is skin color. Or even blue and green. Not very realistic and a bit mono-tone. If that's the case I prefer a black and white hologram of such a model. Although it is fading, people are used to seeing black and white. So this was my way of makeing some realistic colors with only two wavelengths. I think, and it has been discussed here, that if you had to ommit one of the three primaries, the blue is the one to ommit. If you ommit red or green, then you lose not only the red or the green but yellow. There is that magical yellow color again. The free third color if you keep red and green.

Yellow intrigues me. There is no common name for blue and green mixed and it looks like a little of both. But mix red and green and you get what looks to be nothing like either of the two primaries used to make it and its not called reddish green or greenish red, its called yellow.

I could get into pseduo-models. Surely you have seen models on the front of magazines. Do you really think they look like that? Not a blemish, skin color touched up, tummy tucks, highlight in the hair..etc, etc, etc... But we dont call that image on the magazing a pseudo-photograph. But I guess it should as the photo looks nothing like the model. One the other hand, an actor in a movie has all kinds of makup on, some for keeping down reflections, some for covering blemmishes, some for highlighting, some for obtaining the correct skin tone taking into account the lighting and the camera. That person was painted just like my model. Look at the person with all that makup on in real life and look at them on the big screen and they look nothign alike. Are they pseudo-models?

Anyway, you get my point. When workign with light, we have to take into account the type of light and the type of recording medium and we need to make adjustments to make the final product/image/movie look realistic to the viewer.

So I'm not sure what the point is other then trying to make a realistic looking hologram. If the discussion is on what to call it, call it anything. I just hope that the technique becomes useful to someone some day that is using DCG so that they too can add a little color to their holograms. Heck I even have which paints works exactly the best. Since I am out of DCG for the time being, I would love someone to reproduce the effect.

[Johnfp]

If you look at it as a black box:

There is a model with yellow hair, green top wrap, orange dress, some processing takes place, a hologram results with yellow hair, green top, orange dress.

So the models original colours are (partly) reproduced somewhat accurately. The model is not her self anymore afterwards, but you've got the hologram, so who cares

Exactly!!!!

How many of you painted a model of a bannana white to get a better DCG hologram? It turned out yellow and looks just like a bannana but the model was white for better recording properties. Now, that's interesting, is that yellow bannana hologram a false-color hologram? How would anyone know unless you told them? So really had I been secretive on my process, then it would not be a false-hologram. It would have been a "Very Sexy 3 color DCG" hologram...ROTFLOL!!!

[Johnfp]

This fish was done with the same technique and I think the photo does the colors a litle more justice. I know this is on my web page but I am going to post it here so the different colors, orange, yellow and green can be seen better. The object is not as deep as the model and I guess that's why it photographs better. No color redition or photoshop at all.

RYGFishy[1].jpg (12.16 KiB) Viewed 3233 times

[Dinesh]

I think the photo does the colors a litle more justice.

The original colours or the colours you intended?

There are interesting ramifications to this discussion. If colour rendition is not important and the simple fact of many colours makes it a "colour hologram", then is the method of producing a 3D image not as important as the fact that a particular picture IS 3D. In other words, by this argument, the question of whether or not a lenticular is a hologram is made superfluous because the essential component is the fact that both lenticular and holograms are 3D. Now this is a thorny question! In what sense does semantics define technique? We could, in fact, go on to ask, in what sense the perception of 3D itself a semantic illusion? After all, as has been pointed out to me many times, you can see 3D with one eye.

[Johnfp]

The original colours or the colours you intended?

Now, would I really post something off topic. Of course not the original colors. Have you been following the thread? The original colors as I have stated are Blue for green in the hologram. Yellow for red in the hologram. And white for yellow in the hologram. Same as the model.

I just posted the fish as the colors dont smear as much being closer to the plate.

[Dinesh]

Of course not the original colors. Have you been following the thread?

I was referring to the statement:

I think the photo does the colors a litle more justice.

I was wondering in what sense the photo did the colours "a little more" justice? "Little more' relative to what? I mean, in your previous photo, you paint an object so it looks blue. You then shoot it so it now looks green in the hologram. OK, now, was the original colour, before you painted it, green, or was it a lighter shade of blue or was it, for example, red? Assuming that it (the original colour) was green and assuming that you thought that the original green would not reflect laser light, then painting it blue, so it would reflect laser light, then shooting it so it looked like (the original) green, would justify the statement, "the photo does the the colours justice". In this sense, the photo of the hologram is similar to the photo of the original unpainted object. But, if by "doing it justice", you're referring to the fact that the colours in the photo are very similar to the actual colours as seen by a (presumably) white light source of the hologram, then the implication is that the photo reconstruction of the fish hologram is closer to the actual hologram than the photo reconstruction of the lady. In this sense, the colours in the photo of the fish hologram would do the colours of the hologram "more" justice than the corresponding colours in the lady. The "more" is relative to the previous photo.The implication is that the colours of the fish hologram in the photo are more photo-realistic. Of course, you've explained it by saying:

I just posted the fish as the colors dont smear as much being closer to the plate.

So, the "more" is relative to both the previous photo and the reconstruction source and the aberrations in the hologram. Had you reconstructed the lady with a narrower source, then justice would have been equally served.

This has always been the problem of demonstrating colour holography in a photo. I believe Tony brought up the issue recently.

Sorry about the "off topic", but I was intrigued by your statement that you design your technique and your colours to the expectation of the public, as opposed to the knowledgeable realisation of the professionals. You stated that blonde hair was more acceptable than white, that blue grass (in my example) would have been seen as unrealistic. You cited fashion photography as an example where colours are deliberately altered to satisfy a public image rather than photo-realism. Initially, I thought that, having lived near Hollywood for 10 years, white hair in young people is really not so "far out", and "blue grass" is quite acceptable in some circles. But, when I got to thinking about the fashion photography, I thought, "If other fashion photographers see a fashion photo, do they judge the photo, not on the beauty of the model, but on the professionalism of the toucher-upper " (whatever they're called)? Do they comment on the technique and how they would have done it different? Then I thought that art holographers seldom seem to work in three-colour "real" colour holography. The only example I can think of is Gentet, but was he doing art or was he marketing a material? Then I thought, is holography itself a sort of self-serving phenomenon? Do the public see 3D in a hologram because they think that that's what they're supposed to see. Usually - generally! - then public adores 3D in TV or in film, both exploiting visual cues to create a fake 3D, but are generally so-so about holography, which is real 3D. So, do they see holography as an untouched fashion photo, while 3D TV and 3D movies are seen as professional "all the blemishes removed" 3D. In this sense, is a lenticular, or a 3D movie, a "better hologram" than a real hologram. Perhaps this is why the public thinks of "hologram" as so wonderful while praising the wrong medium? You see a model with blemishes and spots and messed up hair, then you see the same model on a magazine all spots and blemishes gone and perfectly coiffured, which are you going to think of as "real". Of course, if you then follow on with that thought, what of "real life". Do the public see 3D movies as "more" 3D than the 3D they see around them? Was Avatar so wonderful because of the blue skinned people, or was it wonderful because the 3D was better than the 3D of the real world?

Anyway, just wanted to give you an idea of what thought processes went through my head as I followed your explanation of colour in your technique.

[Johnfp]

Dinesh, are you threatened by me or just this technique? Just curious. Seems your fixated on what its called and the definition of words.

You question my statement on what I belive the fish photo does the colors a LITTLE more justice and they you quote me later on which was the answer and that is the fish has less depth and thus doesnt smear as much in a photo. I really dont get what your driving at in your constant posts about my words, definitions, usage of words etc... To me that is completely off topic of this thread.

Now if you want to talk about some of the hurdles I had to overcome, or question any of the research, I would be glad to answer you. But from here on out, I am not going to respond to any of your inquisitions that are not on topic.

Have a good day.

[Dinesh]

Jeez, John, sorry, didn't mean to rattle you!

You've presented a technique to a public forum on a technique of colour holography. I believe that Ahmet mentioned that if you post anything on a public forum you are opening yourself to examination. I certainly expect criticism and debate on anything I write.

Colour, and especially colour control, in holography is one of my primary interests. So, naturally, I'm curious as to the limits of your technique. Is this posting of the technique purely for the hobbyist holographer or did you mean it as a serious tool for colour holography by established artists and display holographers? What's the bandwidth? You mention that a specific swelling percentage gives you a specific colour replay. With what bandwidth? Did you test with a spectrophotometer? Right now, I'm being asked to take dcg to it's limits in colour control - well beyond the visible - can I use this technique? How specific is the process? With what error? Can the processing scheme control central frequency and bandwidth? Why don't you submit it in a paper?

Dinesh, are you threatened by me

Well,heck, of course I'm threatened! I'm threatened by anyone with any skill in wielding a laser and some photosensitive material! There are people out there who think I actually know a little about holography! Any day now the truth will out and I'll have to actually brew beer for a living! Can you make a hologram on hops?

I'm joking, of course!

[soct]

nice done...... it is pity that the movie is too short.

[Johnfp]

Colour, and especially colour control, in holography is one of my primary interests. So, naturally, I'm curious as to the limits of your technique. Is this posting of the technique purely for the hobbyist holographer or did you mean it as a serious tool for colour holography by established artists and display holographers? Since I posted it on a public forum it is free for anyone to use as they wish.

What's the bandwidth? I didn't measure bandwidth but to make the technique work you should shoot for narrow band.

You mention that a specific swelling percentage gives you a specific colour replay. I used the color triange to find what the best swell would be and shot for that.

With what bandwidth? Again I did not measure bandwith but narrow band is what you want to shoot for.

Did you test with a spectrophotometer? No

Right now, I'm being asked to take dcg to it's limits in colour control - well beyond the visible - can I use this technique? ABOSOLUTELY!

How specific is the process? With what error? Can the processing scheme control central frequency and bandwidth? Well, in being a DCG holography yourself you know that these variables are hard to simply describe to someone. There is just too much going on. I did test shots prior to the hologram with one of the wavelengths and narrowed in my processing for the swell and bandwidth I was hoping for. Then simply adding the second wavelength which gave the second color and the combination. You're kinda asking for specifics that simply varry from one lab to the other. Not unlike any other type of DCG. I would just try to process for narrow band with a final swell equal to the color shift you want.

Why don't you submit it in a paper? Why? So others have to pay for it from a service? So I submit a paper and get nothing for it, then someone else sells the paper. I'd rather just give it away for free if others can use it.

So, if someone wanted to reproduce this I would first say start with defining your two wavelenghts you are going to start with. Then use the color triangle to see what shift you need to get your green and blue into the reddish and greenish. What two colors red and green you want is up to you and will determine your swell. It just so happens 457 and 514 are far enough apart to give red and green but not too far apart. I would have like to use a shorter wavelength for blue and swell more to get the same green but a redder red. Then once you have decided what you would like your final colors to be, just shoot with one wavelength and dial in your processing to get to that color. Then simply add the second wavelenght and process the same way.