by lobaz » Wed Jan 06, 2021 6:19 am
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
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