Search found 233 matches

by lobaz
Sat Jul 06, 2019 9:08 am
Forum: holoforum administration
Topic: PM problem
Replies: 6
Views: 1626

Re: PM problem

admin_jsfisher wrote:
Fri Jul 05, 2019 2:48 pm
...or it may be working as designed.
Who knows... Anyway, it seems everything is OK now. Thanks for keeping the forum!
by lobaz
Fri Jul 05, 2019 3:34 am
Forum: holoforum administration
Topic: PM problem
Replies: 6
Views: 1626

PM problem

Hi,
it seems something is wrong with PMs - there are two messages hanging in my outbox, one for Ed, the other for Dinesh. It seems they have not been sent, although at least Ed logged in since I wrote them.

Petr
by lobaz
Tue Jul 02, 2019 3:21 pm
Forum: General Holography
Topic: magnified hologram
Replies: 14
Views: 1367

Re: magnified hologram

So it will be magnified (not shrunk) if the reference beam diverges from a location on same side as object but farther away. If that location is twice as far from the plate as the object for instance, we will get 2x transverse magnification and 4x longitudinal. Maybe :) I always have to draw a few ...
by lobaz
Tue Jul 02, 2019 2:59 pm
Forum: General Holography
Topic: magnified hologram
Replies: 14
Views: 1367

Re: magnified hologram

Thanks lobaz that is extremely helpful, not just the result but how you derived it. You are very welcome. However, note that I wanted to keep the formulas as simple as possible. As Dinesh correctly pointed, magnification should be calculated by taking d(xO)/d(xI) rather than my simplistic xO/xI. An...
by lobaz
Sun Jun 30, 2019 1:23 pm
Forum: General Holography
Topic: magnified hologram
Replies: 14
Views: 1367

Re: magnified hologram

Indeed, unconventional methods give you whatever you want. Two ways are straightforward:
You can make a holographic stereogram.
You can make digital model of a real scene and calculate its computer generated hologram of arbitrary scale.
by lobaz
Sun Jun 30, 2019 1:18 pm
Forum: General Holography
Topic: magnified hologram
Replies: 14
Views: 1367

Re: magnified hologram

Simple analysis using conventional methods Suppose the x-z coordinate system. The hologram is located in z = 0. The object is a point located at [xP, zP], where zP < 0. The reference wave comes from the point [xR, zR], where zR < 0. Wavelength lambda is used in the hologram recording. Let's examine...
by lobaz
Sat Jun 29, 2019 8:53 am
Forum: General Holography
Topic: magnified hologram
Replies: 14
Views: 1367

Re: magnified hologram

As far as I know: no.
(At least using just conventional optics.)
by lobaz
Sun May 26, 2019 11:53 am
Forum: General Holography
Topic: BEST FILMS ?
Replies: 7
Views: 963

Re: BEST FILMS ?

Hi, John,
I guess you are aware of Ultimate films, https://shop.ultimate-holography.com/. Slavich PFG-03C is also available as film roll, see http://geola.com/product/pfg-03c-film-rolls/

Petr
by lobaz
Sat Mar 09, 2019 2:56 pm
Forum: Beginning Holography
Topic: Drying silver halides emulsion with alcool ?
Replies: 7
Views: 1097

Re: Drying silver halides emulsion with alcool ?

Alcohol drying of Slavich plates is described by Sergey Vorobyov here:
http://www.holography.ru/les11eng.htm

Anyway, I have no direct experience with it, I do not use Slavich plates any more.
by lobaz
Wed Sep 05, 2018 5:15 pm
Forum: General Holography
Topic: Passing light through bones and brain
Replies: 3
Views: 1102

Re: Passing light through bones and brain

I am not sure if I understood it well - the presentation lacks many technical details. (This is, of course, necessary if one has to explain a complicated stuff to non-experts in 15 minutes.) In the video, there is a laser that gets collimated (probably). Light then passes through a hologram that mod...