stereostereo

At long last I've managed to get a Pentax Stereo Adapter set (mint in box and quite possibly never used BTW). It is my intention to use it on a digital body and mount pairs of prints to view in a Victorian stereo viewer.

The manual states that it must be used at f5.6/f8 with a standard lens but gives no reason, do any of you know why? I would have thought that smaller apertures would have been better.

For those of you who dont know what this is or how it works, let me explain. A beam-splitter attaches to the front of the lens giving two vertical images on one frame each one taken a few inches apart. If you shoot on slide film then you can view the slide with the stereo pair in the accompanying viewer. So now a reason to use up the 6 rolls of slide film in the freezer.

Does anyone have any experience of 3D photography?

Ken

Without making my head hurt too much, I think the reason for the aperture is to make sure there is enough DOF to avoid strange OOF effects. Most stereo images have incredible depth so wide apertures would be a bit odd perhaps.

As for digital, the 1.5x crop factor may be a problem, but, as I said, without making my head hurt too much I'm not totally sure about that.

Best thing is to try it and see what happens!

BTW, we have some nice old stereo card sets at ADAPS, along with a wooden viewer that holds them at the right distance and separates the images optically. It works very well.

I've been in touch with John Hannavy, photographer and historian, who has given me print dimensions etc. link. He used to live in your neck of the woods, John, have you ever come across him?

On the aperture front my thinking was that it would be more desirable to shoot at, say f16, and have greater DoF. Some experimentation is required. I'll try the 40mm DA and the 35mm SMC Takumar, it needs a 49mm filter thread.

I've just had a quick play with it on a film body with 50mm Pentax-F, autofocus doesn't work and it is a very odd experience in the viewfinder, I think this is going to be very much a tripod job if accurate composition is desired.

If we go ahead with the suggestion of a 'Pentax User' badge then perhaps we should include a free 3D viewer for members to view my pictures on their computer monitors.

I have spoken to John Hannavy at camera fairs from time to time, but can't say I know him as such.

John was another of the good writers from Photo Technique.

You need a "normal lens" to have a field of vision similar to the human eye, otherwise the perspective and 3D effects will look strange. If you use a telephoto, it has the effect of "compressing" distance, so the stereo effect is awkward. I tried it when I was a teen and had a blast with different lenses, but life moves on, and interests change. Now, I wish I had kept my stereo adapter, but...

Thank you Gartmore! I have a stero adapter and a pile of Kodachrome 64 to use up. Time to load up the MX and have a play...