by Dinesh » Thu Nov 10, 2011 9:32 am
John, it's statements like these that make you sound like a scientist.
Johnfp wrote:I shifted all colors 16% to bring them back up to their natural depiction of the original model.
I processed for a 16% final swell of 2 wavelengths used. 457 and 514 to bring those color up to 530 and 596 respectively.
Paints were 1) highly reflective for 457 but not 514 for green 2) highly reflective for 514 but not 457 for orange, then a final paint of white for reflectivity of both leading to a final yellow. Then to get that perfect swell.
So in recording with the longest wavelength of my Argon laser, that would be 514. Process swelling of 16% gives about 596, pretty close to orange-red. Now to get some green with that same swell of 16% I had to use the shorter of the wavelengths of my Argon Ion laser. 457 swelled 16% gives about 530 which is green.
But, numbers like these are meaningless. As I've said, it's the bandwidth that's far more important. You can't have a "colour" as a single line, your eyes cannot see a single wavelength. The eye is barely sensitive to a bandwidth of 10nm and most display holograms encompass about 30 to 50nm. You say, "Paints were 1) highly reflective for 457 but not 514" How do you know? What tests determined this? Again, what bandwidth. Most paints are about 50 - 100nm wide, so are these figures you quote central frequencies or FWHM frequencies? Since you've quoted them, the assumption is that you can justify them objectively.
You say that you "process swelled" by 16%. What is "process swelled" as opposed to just plain "swelled". The word "procees swelled" has a scientific air about it. How do you know it was "16%" and not 17% or 21%. Were there any independent tests to determine the swell? Even if it was swelled by "16%", the latent image would have a small bandwidth - that of the laser - but the final image must have a large one. So, at least some part of the emulsion swelled more than 16% and some parts swelled for less. I'm assuming then that the 16% is an average of some sort?
If you put up exact numbers like the above and make out that this was a piece of "research", then of course it'll be seen as a piece of research and critiqued accordingly. If you simply say something like "I painted a model and controlled my processing to get a particular range of colours" then it's a technique and not "research". It's not an original technique, it's been done before, but that does not detract from the fact that you've reinvented the technique. Holographers are constantly re-inventing the wheel every few years. But, "research" gives an aura of scientific precision and so an objective discovery, which this isn't. If this is meant to be research, then, as with any research, the point of stating these parameters is so that they can be critiqued by other researchers. Research is not just a blind statement of unsupported, subjective fact. But a technique can be.
As for me being intimidating, I rarely answer to matters of technique. Everyone has their own technique. I never answer to questions concerning the mechanics or electronics of lasers, simply because I don't have the knowledge. I know a little chemistry, but not enough to answer questions of chemistry. However, when a post involves the physics of holography and the physics of colour, there I am in my element. If the physics is incorrect, I feel I have to correct it because so much misinformation is being passed around these days and no one seems to take the trouble to correct it. For example, this myth that a single frequency is a colour is simply untrue, it can't be. Even lasers have a small bandwidth.
John, it's statements like these that make you sound like a scientist.
[quote="Johnfp"]I shifted all colors 16% to bring them back up to their natural depiction of the original model.
I processed for a 16% final swell of 2 wavelengths used. 457 and 514 to bring those color up to 530 and 596 respectively.
Paints were 1) highly reflective for 457 but not 514 for green 2) highly reflective for 514 but not 457 for orange, then a final paint of white for reflectivity of both leading to a final yellow. Then to get that perfect swell.
So in recording with the longest wavelength of my Argon laser, that would be 514. Process swelling of 16% gives about 596, pretty close to orange-red. Now to get some green with that same swell of 16% I had to use the shorter of the wavelengths of my Argon Ion laser. 457 swelled 16% gives about 530 which is green.
[/quote]
But, numbers like these are meaningless. As I've said, it's the bandwidth that's far more important. You can't have a "colour" as a single line, your eyes cannot see a single wavelength. The eye is barely sensitive to a bandwidth of 10nm and most display holograms encompass about 30 to 50nm. You say, "Paints were 1) highly reflective for 457 but not 514" How do you know? What tests determined this? Again, what bandwidth. Most paints are about 50 - 100nm wide, so are these figures you quote central frequencies or FWHM frequencies? Since you've quoted them, the assumption is that you can justify them objectively.
You say that you "process swelled" by 16%. What is "process swelled" as opposed to just plain "swelled". The word "procees swelled" has a scientific air about it. How do you know it was "16%" and not 17% or 21%. Were there any independent tests to determine the swell? Even if it was swelled by "16%", the latent image would have a small bandwidth - that of the laser - but the final image must have a large one. So, at least some part of the emulsion swelled more than 16% and some parts swelled for less. I'm assuming then that the 16% is an average of some sort?
If you put up exact numbers like the above and make out that this was a piece of "research", then of course it'll be seen as a piece of research and critiqued accordingly. If you simply say something like "I painted a model and controlled my processing to get a particular range of colours" then it's a technique and not "research". It's not an original technique, it's been done before, but that does not detract from the fact that you've reinvented the technique. Holographers are constantly re-inventing the wheel every few years. But, "research" gives an aura of scientific precision and so an objective discovery, which this isn't. If this is meant to be research, then, as with any research, the point of stating these parameters is so that they can be critiqued by other researchers. Research is not just a blind statement of unsupported, subjective fact. But a technique can be.
As for me being intimidating, I rarely answer to matters of technique. Everyone has their own technique. I never answer to questions concerning the mechanics or electronics of lasers, simply because I don't have the knowledge. I know a little chemistry, but not enough to answer questions of chemistry. However, when a post involves the physics of holography and the physics of colour, there I am in my element. If the physics is incorrect, I feel I have to correct it because so much misinformation is being passed around these days and no one seems to take the trouble to correct it. For example, this myth that a single frequency is a colour is simply untrue, it can't be. Even lasers have a small bandwidth.