4x5 camera shutter

[hearbob50]

Hi, After feedback. My background is Photo, analog and digital. I am thinking that using a 4x5 camera shutter might work. Taking off the front and rear lens elements, mounting the lens board and using either the T or B setting on the shutter. Any thoughts?

[BobH]

If making Denisyuk type holograms, it will work fine. If making "split beam" holograms, mount it to something not connected to the table used for the recording system to avoid vibration caused by it.

[Din]

Bear in mind that the exposure could be as long as 30 mins or longer. So, T mode (which I understand means that, once open, the shutter stays open till you press the shutter again) could be a huge drain on the camera battery - assuming it's a digital camera. B mode (which I understand means you have to keep hold of the shutter) could be wearing if you need to hold the shutter for half an hour or more.

[hearbob50]

Thanks. to answer, this is a mechanical shutter. it is mounted on a square 6" lens board. there are three parts. a front element, the shutter and a rear element. I will detach the elements which contain all the len groupings. I will be anchoring the lens board. B stands for bulb and is open until you release the shutter. T for time opens when you depress the shutter and closes when you press again. I will trigger it via a 24 inch cable release to minimize movement.

[Din]

If the time T can extend to between 20 and 40 minutes (perhaps greater), then it'll be OK. The exposure time depends on the laser power, the material and the dimensions of the object. The smaller the object, the shorter the exposure because the laser power is more concentrated over a smaller area. And, of course, it depends on the stability of your system - plate holder, object etc.

It would help if you could snake the cable outside the room where you're exposing for long exposures. The reason is that you have to stand absolutely still over the time of the exposure, otherwise air currents generated as you move will cause motion in the shot. As a rule of thumb, if the exposure was less than 5 minutes, I'd stay in the room.