RE: Pinhole and SLR

[Wayde Allen <allen@xxxxxxxxxxxxxxxx>]

On Fri, 30 May 1997, Joe Berenbaum wrote:

> >I have tested the pinhole using fast color negative film, and
> >the pinhole is working fine.

I just printed the first contact sheets from mine and things seem to be
working fine here too.

> >As I told earlier, the viewfinder image is VERY dim, but I was
> >able to see something on a clear day. When I tried it it was winter,
> >and maybe the snow was so bright that it helped...
> >Soon I will find out how it is working in summer with Konica IR film.

I'll have to try this over the weekend.  Like I said, I haven't actually
looked through mine, but it has to be pretty dim.

> One accessory that is useful for times like this is the Russian turret
> multi-finder. Just stick it in the hotshoe and you have a
> parallax-correctable viewfinder for 28/35/50/85?/135mm. Or there is the
> Russian 35mm brightline finder also, which is a lot cheaper but not nearly
> so good- although it works, which is all that is really important. Accessory
> viewfinders are useful with a B+W 092 or darker filter on an SLR and could
> maybe become quite useful with a pinhole also in lower light levels.

These sound interesting.  Where can you get one?

> I think
> the trick is to stop "thinking SLR" when the image gets dark....

Yes - I agree.
 
> Or maybe one could learn something from Willem-Jan and put the pinhole
> between the film rails? ;-}

No, the pinhole is the lens.  There are no other optical elements.  What I
had intended to show with my previous post is that the closer the pinhole
gets to the film plane, the harder it is to make.  Putting the pinhole at
the film rails would require a VERY small pinhole.  If the film rail was
1mm thick, you'd need a pinhole on the order of 0.047mm!  This is much
harder to make than a 0.3mm hole.  Also, the resulting wide-angle view
would be limited by the front lens mounting mechanism of the camera. I
would also guess (never tried it) that the image would be pretty small.

It is simply easier to get a good quality pinhole if the pinhole to film
distance is larger.  The pinhole size and shape is less critical in this
case. The 35mm camera body used as a pinhole camera simply gives you a
nice shutter and film handling mechanism.  For IR film this could be a
very real advantage. 

- - Wayde







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