by Din » Fri Jul 24, 2026 1:50 pm
m_holo17 wrote: ↑Thu Jul 23, 2026 2:07 pm
https://cdn.phototourl.com/free/2026-07 ... b86347.jpg
Yes that is correct
Here is my setup for a single beam reflection hologram, I’m using Bayfol hx200, an osram pl530 laser at 35-40 degrees on a tripod that’s 32inches from my plate and object resting on a cinder block as a base and another as a backing, I’m exposing it for 10-20 seconds and I’m planning on making a holo of a plastic figure that’s about 7 inches tall. I have successfully made small scale holograms of metal and ceramic objects with this setup.
I suspect part of the problem is lack of stability. You say the object rests on a cinder block, but simply resting may be ok for low exposures, but may be unstable for longer exposures. Without pictures, I can't say how it's resting, but it would probably be advantageous to glue the object to the cinder and to the base ("Hot glue and string - the holographers best friends" - my instructor, Edwina Orr, told me forty years ago. In 40 years of holography, I've never forgotten her advice!). For a given sensitivity, the exposure time depends on the sensitivity of the medium - bayfol hx200 has a sensitivity of 20 mJ/cm² - and the area covered by the beam. The further back you take the laser, the greater is the laser light coverage of your plate, and the longer the exposure time required. However, the exposure time goes as the square of the distance from the laser, so the exposure time goes up non-linearly. Your setup may be good enough for low exposure times, but may be inadequate for the longer exposures needed as you pull the laser back. I've analysed it with some mathematics, if you can follow it.
Plastic may not be the ideal material, it expands depending on the plastic. Also, the object should be white to reflect as much of the laseer light as possible. I sprayed all of my objects with matte white paint.
- exp_time.jpg (94.64 KiB) Viewed 1475 times
[quote=m_holo17 post_id=73902 time=1784833653 user_id=11993]
[url]https://cdn.phototourl.com/free/2026-07-23-9f2b34fb-f7ea-4cde-aa36-ab4a84b86347.jpg[/url]
Yes that is correct
Here is my setup for a single beam reflection hologram, I’m using Bayfol hx200, an osram pl530 laser at 35-40 degrees on a tripod that’s 32inches from my plate and object resting on a cinder block as a base and another as a backing, I’m exposing it for 10-20 seconds and I’m planning on making a holo of a plastic figure that’s about 7 inches tall. I have successfully made small scale holograms of metal and ceramic objects with this setup.
[/quote]
I suspect part of the problem is lack of stability. You say the object rests on a cinder block, but simply resting may be ok for low exposures, but may be unstable for longer exposures. Without pictures, I can't say how it's resting, but it would probably be advantageous to glue the object to the cinder and to the base ("Hot glue and string - the holographers best friends" - my instructor, Edwina Orr, told me forty years ago. In 40 years of holography, I've never forgotten her advice!). For a given sensitivity, the exposure time depends on the sensitivity of the medium - bayfol hx200 has a sensitivity of 20 mJ/cm² - and the area covered by the beam. The further back you take the laser, the greater is the laser light coverage of your plate, and the longer the exposure time required. However, the exposure time goes as the square of the distance from the laser, so the exposure time goes up non-linearly. Your setup may be good enough for low exposure times, but may be inadequate for the longer exposures needed as you pull the laser back. I've analysed it with some mathematics, if you can follow it.
Plastic may not be the ideal material, it expands depending on the plastic. Also, the object should be white to reflect as much of the laseer light as possible. I sprayed all of my objects with matte white paint.
[attachment=0]exp_time.jpg[/attachment]