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.......The distance between the two plates (for the microscope objective and for the mounted pinhole) is adjustable. I should write: The MIN and MAX distance between the two plates (for the microscope objective and for the mounted pinhole) is adjustable, so that also longer or shorter than normal m...

I am very satisfied with the spatial filter from HOLMARK (an Indian producer). Model number SFA-S http://holmarc.com/spatial_filter_mounts.php Good quality, with micrometer movement and NOT expensive. About five years ago, I paid ca. USD140 each new. Additionally, it is very versatile: The distance ...

I'm having some difficulty with a broadband beamplitter.......... Joe, your cube's characteristics seems to be OK ( http://search.newport.com/?x2=sku&q2=5811 ). In my opinion, the problem is caused by the wave plate. I may have a mounted Double Fresnel Rhomb Assembly (achromatic) available, if ...

Paulos, I don't believe the coherence length of a laser with an etalon in it is limited to twice the cavity length. Bob, The equations are from Hariharan's "Optical Holography, Principles, Techniques and Applications". Those I've used had much, much greater coherence length than that. Are...

1) The coherence length of a HeNe laser WITH AN ETALON is proportional to the mirror separation 2) The Coherence Length of a HeNe WITHOUT AN ETALON = c/Bandwidth . Bandwidth is typically 1.7GHz for a HeNe laser and 3.5GHz for an Ar+ laser, hence the coherence length is ca. 17cm for HeNe and ca. 8cm ...

..... The orginal question was thick film results in narrow band while thinner was BB. Your results indicate the opposite. I found the same thing, I thicken up my film I observed more BB deeper yellow. Adding more water (making the film thinner) I got a greener result that also was easier to reproc...

Last night I was testing some film and used a very flat plaster of paris slab. Every result looked as though it had moved. The were fairly large rings. The image was only visible a odd angles (not the angle I shot). ....... It looks like your object expanded or contracted during exposure. How long ...

John, Your film is strong birefringent, and the orientation of its optic axis varies quasi randomly. Without a a lambda/4 plate, I am afraid that almost all your holograms will show these lines. To overcome this problem, you should use a circular-polarized beam to illuminate H1, whereas the emulsion...

.................. If you can get your hands on some Rhodamine 6G (not an easy task) then you can combine this with MB and the rest of Jeff Blyth's system for full RGB sensitvity via the "Chinese" method of Zhu et al . .................. Zhu's paper: "True-color reflection holograms ...

There is an easy way to first check if your safelight is really safe: In your darkroom, turn on your safelight and look at it through the emulsion. If it looks glass clear, light is fully safe. If you see it more or less gray, emulsion absorbs light and may get fogged. I am using red LEDs for green ...