First attempt

Starting point for beginners questions.
Serge_satriani

First attempt

Post by Serge_satriani »

Hello everyone. I just started wiyh holography still trying to understand how all of this works.

On my 4th intent I get some results, but very far from get a good hologram. I'm using a 532 nm battery laser. With dcg formula (100/12/3)
https://www.instagram.com/p/CJWqX25jjqR ... 1jfdccof7d
John Klayer
Posts: 273
Joined: Thu Jan 08, 2015 2:28 am

Re: First attempt

Post by John Klayer »

You mention a 532nm battery laser. Can you be more specific?
lobaz
Posts: 280
Joined: Mon Jan 12, 2015 6:08 am
Location: Pilsen, Czech Republic

Re: First attempt

Post by lobaz »

Hi Serge,
I think it is quite impressive for a begginer. Starting with DCG is not easy, as there are too many variables what can get wrong. Where are you located? Did you try to find any holographer nearby?

Petr
Serge_

Re: First attempt

Post by Serge_ »

Hello John, the laser I'm using is a D. X 303: https://articulo.mercadolibre.com.mx/ML ... ntinua-_JM

It claim to be 5000 mw, but it does not make sense to me.

My exposure time is 5 minutes, then fix with light 1 minute and then 3 IPA
Baths ( 50/50, 80/20, 100).

Lobaz, I'm from Mexico city. Don't know more people here interested in holograms. I'v been willing to learn holography for a while, I realise there is a long way to go to learn.

Yesterday tried to make a larger one ( 4*6) with my object 1cm away from the emultion and 10m exposure. But didn't work.

Anyway. I would appreciate any advice.

Regards
lobaz
Posts: 280
Joined: Mon Jan 12, 2015 6:08 am
Location: Pilsen, Czech Republic

Re: First attempt

Post by lobaz »

Hi Serge,
sorry, I don't know any Mexican holograher.

1. My first suspect would be the laser. Are you sure it is stable enough for holography? Did you build a Michelson interferometer and observed the fringes over a long period of time? Or even better, can you analyse the laser spectrum?

2. The second suspect is indeed the mechanical stability of the system. Multi-minute exposure are so sensitive to anything! A beginner can hardly believe what tiny imperfections can destroy the hologram.

3. Then, of course, comes your material and its processing.

Without experience, it is close to impossible to tell if the problem is in the laser, in the setup or in the material/processing.

If you want to keep your laser, try to get some reliable material (the best would be green sensitive AgX plates) and start with small holograms, short exposures and the simplest possible setup (single beam Denisyuk, plate in contact with simple rigid object such as a coin).

Or, ask here in the "For Sale / Trade" section for a reliable laser that fits within your budget. Then again, make the simplest possible setup and make very small holograms so that you can put a lot of light there and your exposure is well below one minute.

The key: the best way to start is to ensure that all items in my 1-2-3 list are reliable (in the worst case, two of them are 100% reliable). Then slowly introduce things you are not sure about.

Petr
Joe Farina
Posts: 804
Joined: Wed Jan 07, 2015 2:10 pm

Re: First attempt

Post by Joe Farina »

Hola, Serge. Excellent result after only a few tries, superb in fact for DCG. The laser looks like an unlikely candidate for holography, yet you did a 5-minute exposure without banding in the image (mode-hopping), so the laser can be surprisingly stable. But stability can come and go. Possibly this is a 1 watt laser (1000mW) but the description on the webpage is confusing. If it's putting out anything close to 1 watt, then that would be a huge help for DCG, which as we know is very slow. The possible reason for failure of the 10-minute exposure is that it was too long (compared to the 5-minute). Or maybe the laser was generally unstable for that particular exposure. It might be good to keep under 5 minutes, and keep the images smaller, until you gain more experience. As mentioned, it would be a good idea to do some testing with a simple interferometer setup, for both the laser and table (together or individually) to get a better idea of overall stability.
Serge_Satriani

Re: First attempt

Post by Serge_Satriani »

Muchas gracias por tus comentarios. Me sorprendió obtener estos resultados sin experiencia o con un láser adecuado, es muy motivador. Ahora quiero hacer las cosas de la manera correcta y creo que iré por un mejor láser. Entonces, ¿qué tipo de láser me recomiendan para mejorar mis hologramas con un presupuesto de $ 50 a $ 100 (para DCG)? Mientras tanto seguiré experimentando con los de formato pequeño y el láser chino. También intentaré hacer un interferómetro. En realidad, mi configuración es la más simple: quité la lente de enfoque del láser, no uso ninguna otra óptica o filtro. Mi mesa es un cofre enorme lleno de cosas, por lo que es un poco pesado, el láser está pegado a una pared con un clavo y yo vivo en un cuarto piso, pero el área es muy tranquila en general.
También leí que con TEA se mejora la sensibilidad de la emulsión. Pero realmente no puedo entender cómo se aplica.

Best regards.

Sergio.
Joe Farina
Posts: 804
Joined: Wed Jan 07, 2015 2:10 pm

Re: First attempt

Post by Joe Farina »

That is amazing, DCG holography on the 4th floor with a Chinese laser pointer, no optics, on a heavy chest. And the image was good and bright. To be honest, I wouldn't do anything except what you are doing already. I wouldn't even bother with an interferometer for now. (It might be good to start saving for another laser, expect to spend around $1,000 or more.)

I would just try to keep duplicating your excellent results. Maybe spend more time on varying the processing (but it already looks good). I would try different objects. If you start to see banding on the object in the holographic image (alternating dark and bright lines or bands across the object) that means the laser is changing wavelengths slightly during the exposure (mode-hopping). Frankly, I'm amazed your laser produced such a good result.
Serge_Satriani

Re: First attempt

Post by Serge_Satriani »

Serge_Satriani wrote: Wed Jan 06, 2021 12:41 pm Muchas gracias por tus comentarios. Me sorprendió obtener estos resultados sin experiencia o con un láser adecuado, es muy motivador. Ahora quiero hacer las cosas de la manera correcta y creo que iré por un mejor láser. Entonces, ¿qué tipo de láser me recomiendan para mejorar mis hologramas con un presupuesto de $ 50 a $ 100 (para DCG)? Mientras tanto seguiré experimentando con los de formato pequeño y el láser chino. También intentaré hacer un interferómetro. En realidad, mi configuración es la más simple: quité la lente de enfoque del láser, no uso ninguna otra óptica o filtro. Mi mesa es un cofre enorme lleno de cosas, por lo que es un poco pesado, el láser está pegado a una pared con un clavo y yo vivo en un cuarto piso, pero el área es muy tranquila en general.
También leí que con TEA se mejora la sensibilidad de la emulsión. Pero realmente no puedo entender cómo se aplica.

Best regards.

Sergio.

Sorry, I dunno why my text come up in spanish, here is the english version:

Thank you for your comments. I was surprised to get these results without experience or with a proper laser, it is very motivating. Now I want to do things the right way and I think I will go for a better laser. So what kind of laser do you recommend to enhance my holograms on a budget of $ 50 to $ 100 (for DCG)? In the meantime I will continue to experiment with the small format and the Chinese laser. I will also try to make an interferometer. Actually my setup is the simplest - I removed the laser focus lens, I don't use any other optics or filters. My table is a huge chest full of stuff, so it's a bit heavy, the laser is attached to a wall with a nail and I live on the fourth floor, but the area is very quiet in general.
I also read that with TEA the sensitivity of the emulsion is improved. But I can't really understand how it is applied.

Best regards.

by Joe Farina » Wed Jan 06, 2021 4:25 pm

That is amazing, DCG holography on the 4th floor with a Chinese laser pointer, no optics, on a heavy chest. And the image was good and bright. To be honest, I wouldn't do anything except what you are doing already. I wouldn't even bother with an interferometer for now. (It might be good to start saving for another laser, expect to spend around $1,000 or more.)

I would just try to keep duplicating your excellent results. Maybe spend more time on varying the processing (but it already looks good). I would try different objects. If you start to see banding on the object in the holographic image (alternating dark and bright lines or bands across the object) that means the laser is changing wavelengths slightly during the exposure (mode-hopping). Frankly, I'm amazed your laser produced such a good result.
Thanks so much for encourage me. I'll take your advise and keep doing this small ones. I will be in touch. Saludos.
lobaz
Posts: 280
Joined: Mon Jan 12, 2015 6:08 am
Location: Pilsen, Czech Republic

Re: First attempt

Post by lobaz »

So what kind of laser do you recommend to enhance my holograms on a budget of $ 50 to $ 100 (for DCG)?
Look in the For Sale / Trade section of the forum. The user soda offers a nice reliable 100 mW green laser, holomaker may have some as well. Send them a private message or post a request to that section. If you wanted to spend more than 100 USD, the user 142laser is the guy you are looking for.
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