Where did I go wrong? Is my methodology bad? [PICTURE]

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beanland

Where did I go wrong? Is my methodology bad? [PICTURE]

Post by beanland » Sat Sep 11, 2010 5:57 pm

Hello all,

I attempted my first hologram last week and came up with something, well, not very holographic. In fact, it's just kind of a smudgy looking aura on a piece of glass. I was wondering if I could get some help determining where I messed up. There is no change in what I see regardless of lighting conditions or angle at which it is viewed.

I've attached a picture at the bottom, but I'd like to let you know what materials I'm using here:

Laser: I'm using a diode laser pulled out of a pen/laser pointer combo (almost identical to the one found at this shop (http://store.bothfull.com/4in1ledfllap.html) with these specifications: "Wave Length: 650NM Max Output<5MW Class III Laser ").
Film: PFG-03M 63x63mm plates from Integraf
Developing Solution: JD-4 Holography Processing Kit with the Form-A-Flo 600 wash (all from Integraf)
Exposure time: 20 seconds
Setup: Simple white-light reflection as found at http://www.holokits.com/a-simple_holography.htm

I realize now that my emulsion side was facing towards the laser and not my object (a Lego minifig)--would this be the cause of my problem?

Here is my photograph of the attempt:
Image

Appreciate the help. Thanks!

Colin Kaminski

Where did I go wrong? Is my methodology bad? [PICTURE]

Post by Colin Kaminski » Sat Sep 11, 2010 7:35 pm

You need a halogen spot or similar point source at the same angle as the laser was to look for an image. A good way is to take the plate into the sun and spin it around till you see some color. You can use the emulsion to either side and get a hologram but it is better to use it toward the object in order to protect the gelatin during display.

Please try this and post your results.

JohnFP

Where did I go wrong? Is my methodology bad? [PICTURE]

Post by JohnFP » Sat Sep 11, 2010 11:56 pm

First of all, lego mini figures stink. they move all over the place.
Second, you need to set you laser up with an interferometer and see if it produces fringes
Third, 20 seconds seems kinda short for a laser pointer. You need to do some test stips on exposure times.
Fourth. keep with it, it will comel.

Best of luck,
G.

rzeheb

Where did I go wrong? Is my methodology bad? [PICTURE]

Post by rzeheb » Sun Sep 12, 2010 12:45 am

As Colin suggests, you may actually have an image but not be able to see it. The sun's a great source of viewing light, but make sure its a clear sunny day. If the sun is behind any clouds the light becomes diffused and it's no longer a point source. Another good light is a single, bright white LED. I keep a small one on my keychain and it works great. Make sure you shine the light from each of the possible four sides then flip the plate around and do it again. The light should hit the plate at the same angle as the laser reference beam and from the same side of the plate as you are looking at. If you don't see your image, don't give up! It may take a little effort, but you will be rewarded with the results.
Ron

JohnFP

Where did I go wrong? Is my methodology bad? [PICTURE]

Post by JohnFP » Sun Sep 12, 2010 1:14 am

5mw - 20 sec?

BobH

Where did I go wrong? Is my methodology bad? [PICTURE]

Post by BobH » Sun Sep 12, 2010 1:24 am

And if you thought the emulsion was up in the trays of chemicals and now know it was down, the bleach may not have had a chance to get to the center.

beanland

Where did I go wrong? Is my methodology bad? [PICTURE]

Post by beanland » Sat Sep 18, 2010 2:07 am

Thanks for all the quick responses and helpful tips. Here are some responses:
rzeheb wrote:As Colin suggests, you may actually have an image but not be able to see it. The sun's a great source of viewing light, but make sure its a clear sunny day. If the sun is behind any clouds the light becomes diffused and it's no longer a point source. Another good light is a single, bright white LED. I keep a small one on my keychain and it works great. Make sure you shine the light from each of the possible four sides then flip the plate around and do it again. The light should hit the plate at the same angle as the laser reference beam and from the same side of the plate as you are looking at. If you don't see your image, don't give up! It may take a little effort, but you will be rewarded with the results.
Ron
Unfortunately, it doesn't seem to work with whatever light I'm shining on it, from whatever angle it's being shone. I've tried my halogen lamps, the sun, and a bright white LED flashlight. Nothing's showing up, no indication of anything being there. Correct me if I'm wrong, but shouldn't I see some difference, even if its of some indiscernible blur--some color, movement at all? Nothing changes with varying points of light, movement of the plate or my viewpoint.
JohnFP wrote:First of all, lego mini figures stink. they move all over the place.
Second, you need to set you laser up with an interferometer and see if it produces fringes
Third, 20 seconds seems kinda short for a laser pointer. You need to do some test stips on exposure times.
Fourth. keep with it, it will comel.

Best of luck,
G.
I guess I should be using something a little more stable, certainly. But am I incorrect in assuming that object vibrations in holography are similar to in photography, as they'd produce something blurry rather than a blank slate?

Where should I go to learn up about fringes? I'm entirely new to this and I'm foreign to this concept. I don't have an interferometer, so I can't quite test this out at the moment.

The Integraf site suggests 10 seconds with its 3-4 mW diode; the booklet I received with my plates implied a time of 20 seconds with the kind of diode I am using. What would you suggest for this type of pointer? 30? 40? Something else?

Here are two other things I've noticed that I may have messed up with--would they have caused this problem?

Warm-up Time: I did not allow my laser to "warm-up." It may have been on for a minute or so before I attempted the exposure, if that. Is it necessary to "warm-up" my diode? What is an acceptable time for this? A few minutes? A half hour?

Green Safe-light: I read that I could use a "green safelight" with this, and I did. At least, I used a green light. (Here's a link to one similar to the one I purchased: http://www.buyblueusa.com/PROD/VA0022.html). Could that have caused a problem?

I appreciate all the help. Thanks so far for everything!

Tom B.

Where did I go wrong? Is my methodology bad? [PICTURE]

Post by Tom B. » Sat Sep 18, 2010 8:29 am

Object (or plate) movement due to vibrations or whatever in holography reduces the image brightness. In mild cases you get contour lines of darkness where there is no image. At worst no image at all. It doesn't take much rumble and vibration from building air conditioning to totally wash things out. Just to gain confidence and know what you are up against, I highly recommend setting up a simple interferometer. This really gives you a sense of how stable things are. I'll post back if I find a good reference for this. Books: I highly recommend Graham Saxby's "Practical Holography". I also liked John Iovine's " Homemade Holograms".

If you look at the plate (under safelight) after development, but before bleaching, you can get some idea of how much exposure it has received. All black = overexposed, clear = underexposed, somewhere in between = OK exposure. There's a lot of room for error as long as you're in the ballpark. You can get an idea of what all black is by exposing a plate (or a piece of one) to sunlight for a few minutes and developing. This is as black as it can get with overexposure. To get an idea of whether you have problems with your safelight etc., try developing (without bleaching) some unexposed plate. It should be nearly clear. Glass cutting skills (in the dark) can save you some money here.

Re warm-up time, allow for lots. If you can use external batteries for your pointer and let things settle for several minutes, all the better. If you are trying to make holograms in a noisy, high-traffic area, you will need to get into all the complications such as isolation tables, rubber tires etc. or do the work in a quieter location.

rzeheb

Where did I go wrong? Is my methodology bad? [PICTURE]

Post by rzeheb » Sat Sep 18, 2010 11:58 am

Hi Beanland,
O.K., so you've verified that you don't have an image. Movement may be the next place to really focus on. We are talking about movement on a microscopic scale. It's possibly that YOUR actions (such as lifting a shutter) caused movement. A little movement = no image. BTW, where are you located (you can put that into your profile)? You may not be too far from someone on this forum.

beanland

Where did I go wrong? Is my methodology bad? [PICTURE]

Post by beanland » Sat Sep 18, 2010 9:56 pm

All right, I'll give these suggestions a try--probably not until sometime next week, because I need to set something more stable up. I appreciate all of the suggestions. And I'm in the Milwaukee area, so if you know of anyone around here who's handy and could maybe show me a few tricks, that'd be fantastic. Again, thanks so much for the help. I'm excited to get this figured out and to be producing something.
Edit: I just thought I'd ask for some suggestions on where to go for an interferometer--or any suggestions on what to watch out for when I'm looking for one. Thanks!

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