Good idea Jem - are we still OK for our meeting on 13th
BRgds
John
Reference Beams used in H1 to H2 transfer
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Jem
Reference Beams used in H1 to H2 transfer
Certainly are - i'm looking forward to itJohn Sonley wrote:...are we still OK for our meeting on 13th
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Konrad
Reference Beams used in H1 to H2 transfer
John, I checked diagram on Saxby book, it is definitely mistake on this picture - H1 phrase should be on H2 place (and vice versa). Regarding convergence beam - previously I used diverging beam for H2 record and I got distorted image (ellipses instead of circles especially in more deep image). Later I bought second collimating mirror and my problems about distorsion were solved.
I also have little offtopic question especially to Kaveh: I'm going to make H1 transmission master on green plate (with green laser 532nm) and later illuminate it with red HeNe. I want use 56,6 degrees angle for recontruction with Hene (usual Brewster) so I must record hologram with 44.56 degrees with green laser (according with dispersion compensation formula). Is it fine combination or anyone has better suggestion?
I also have little offtopic question especially to Kaveh: I'm going to make H1 transmission master on green plate (with green laser 532nm) and later illuminate it with red HeNe. I want use 56,6 degrees angle for recontruction with Hene (usual Brewster) so I must record hologram with 44.56 degrees with green laser (according with dispersion compensation formula). Is it fine combination or anyone has better suggestion?
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Colin Kaminski
Reference Beams used in H1 to H2 transfer
John, I am quite sure that the pulsed master was uncollimated in Graham's figure. The two holograms show the exact distortions you would expect. The low damage threshold of collimation mirrors and the large size makes them hard to use in pulsed setups. The holograms I have from Laser Reflections were clearly made with a low power double convex diverging lens, no spatial filter and diverging beams for both the H1 and H2. The images are great but they do show swing. If you copied the H1 with with a converging reference some of the distortion would be removed. However I am sure Graham would look at the figure and let you know if it was mislabeled. He is very friendly.
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Kaveh
Reference Beams used in H1 to H2 transfer
Hi Konrad. Not checked the numbers but I am sure you are right. If you really want to compensate for the wavelength change I think you want to change the distance of the reconstruction beam too.Konrad wrote:I also have little offtopic question especially to Kaveh: I'm going to make H1 transmission master on green plate (with green laser 532nm) and later illuminate it with red HeNe. I want use 56,6 degrees angle for recontruction with Hene (usual Brewster) so I must record hologram with 44.56 degrees with green laser (according with dispersion compensation formula). Is it fine combination or anyone has better suggestion?
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Konrad
Reference Beams used in H1 to H2 transfer
Yes I forgot about distance, reconstructed image with red laser will be closer plate than with green laser. Thanks
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John Sonley
Reference Beams used in H1 to H2 transfer
Konrad - many thanks for your reply.
I likewise think that the 'H1' and 'H2' indications on the Saxby Fig. I referred to are transposed - if that is the case I think that 'we are all singing the same tune'
Do you have an e-mail address for Graham Saxby - if so, please send in a PM - I found two addresses on the internet but I'm not sure if they're valid - they didn't bounce-back
BRgds
John
I likewise think that the 'H1' and 'H2' indications on the Saxby Fig. I referred to are transposed - if that is the case I think that 'we are all singing the same tune'
Do you have an e-mail address for Graham Saxby - if so, please send in a PM - I found two addresses on the internet but I'm not sure if they're valid - they didn't bounce-back
BRgds
John
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John Sonley
Reference Beams used in H1 to H2 transfer
Thanks Konrad - I also think that the 'H1' and 'H2' markings on the Fig. should be transposedKonrad wrote:John, I checked diagram on Saxby book, it is definitely mistake on this picture - H1 phrase should be on H2 place (and vice versa). Regarding convergence beam - previously I used diverging beam for H2 record and I got distorted image (ellipses instead of circles especially in more deep image). Later I bought second collimating mirror and my problems about distorsion were solved.
Does anyone have Graham Saxby's e-mail address - please send by PM and I'll ask him the question. I've tried to contact him before but perhaps I'm using dormant e-mail addresses
BRgds
John
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Ed Wesly
Reference Beams used in H1 to H2 transfer
I usually only look at the web when I am at work, and I am lucky enough to have an "off-campus" day on Monday, (don't worry I have 4 10+ hours work days, with 2 back to back classes on 3 of those days) so that's why I haven't chimed in on this thread yet.
Pseudo means false, so the pseudoscopic view is the false view, the inside out one, and typically the real image of a hologram is pseudoscopic, when the viewer is on the same side of the hologram as the image. Surprisingly, the real image from a lens is not pseudoscopic, however left and right and up and down are inverted. Stereo pairs, like Viewmasters, can be made to be pseudoscopic by switching the left eye view for the right eye by rotating the disc.
Ortho means true or correct, so the orthoscopic image is the correct orientation. the first photographic plates that could see green and made foliage lighten up were christend orthochromatic, or correct color.
You gotta watch those Saxby books, a lot of times he saw or heard somebody do something and he published it, regardless of testing it. For the most part he is on the right track, but there are a few things I could quibble about but I don't have the time right now. So the business about the converging reference beam on an H2 does ring true theoretically, however I have never seen anyone do it in practice. That extra collimating or focusing optic can pick up dirt and leave unsightly blemishes on the hologram's surface!
Back to the Saxby book, if anyone ever comes across a copy of I don't know what edition, but it had an embossed hologram on the cover and an Applied Holographics Holo-Copier hologram inside, and a dedication to me signed by Graham (something like "to my holographic fiend, Ed Wesly") I will pay a nice reward for it! Some Scurvy knave stole it from the School of the Art Institute's Holography Lab ca.1996, and I would really appreciate it having it back! Same villain also copped my copy of Nils Abramson's "Making and Evaluation of Holograms", with a personal dedication. How can this bastard sleep at night? And I am sure the book was never used by them.
Pseudo means false, so the pseudoscopic view is the false view, the inside out one, and typically the real image of a hologram is pseudoscopic, when the viewer is on the same side of the hologram as the image. Surprisingly, the real image from a lens is not pseudoscopic, however left and right and up and down are inverted. Stereo pairs, like Viewmasters, can be made to be pseudoscopic by switching the left eye view for the right eye by rotating the disc.
Ortho means true or correct, so the orthoscopic image is the correct orientation. the first photographic plates that could see green and made foliage lighten up were christend orthochromatic, or correct color.
You gotta watch those Saxby books, a lot of times he saw or heard somebody do something and he published it, regardless of testing it. For the most part he is on the right track, but there are a few things I could quibble about but I don't have the time right now. So the business about the converging reference beam on an H2 does ring true theoretically, however I have never seen anyone do it in practice. That extra collimating or focusing optic can pick up dirt and leave unsightly blemishes on the hologram's surface!
Back to the Saxby book, if anyone ever comes across a copy of I don't know what edition, but it had an embossed hologram on the cover and an Applied Holographics Holo-Copier hologram inside, and a dedication to me signed by Graham (something like "to my holographic fiend, Ed Wesly") I will pay a nice reward for it! Some Scurvy knave stole it from the School of the Art Institute's Holography Lab ca.1996, and I would really appreciate it having it back! Same villain also copped my copy of Nils Abramson's "Making and Evaluation of Holograms", with a personal dedication. How can this bastard sleep at night? And I am sure the book was never used by them.
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John Sonley
Reference Beams used in H1 to H2 transfer
Ed, thanks so much for your reply.
Regarding that Saxby book, it's the 2nd Edition, by the way - yes I do have a copy - but only one and I think I follow its advice more than Edition 3, which I find more detailed and difficult to understand
Regarding the converging H2 reference beam - I use large plano-convex lenses to adjust my beams and it is fairly easy to obtain diverging, collimated or converging beams on my sand table - have a peep at my set-up on www.jmshome.demon.co.uk
The proof of the pudding .................. - as they say is testing out the theory and I've a most interesting (to engineers) H1 of a pneumatic actuator, it's on the web site
Sometime I'll try out all three settings of the H2 reference beam, as described above - and I'll let you have my answer, providing something definitive comes out of the study
BRgds
John
Regarding that Saxby book, it's the 2nd Edition, by the way - yes I do have a copy - but only one and I think I follow its advice more than Edition 3, which I find more detailed and difficult to understand
Regarding the converging H2 reference beam - I use large plano-convex lenses to adjust my beams and it is fairly easy to obtain diverging, collimated or converging beams on my sand table - have a peep at my set-up on www.jmshome.demon.co.uk
The proof of the pudding .................. - as they say is testing out the theory and I've a most interesting (to engineers) H1 of a pneumatic actuator, it's on the web site
Sometime I'll try out all three settings of the H2 reference beam, as described above - and I'll let you have my answer, providing something definitive comes out of the study
BRgds
John