Re: Polycarbonate bodies

[Cameron Shaw <cameron@xxxxxxxxxxxxx>]

On Sun, 23 Feb 1997 22:42:00 GMT Richard Lovell wrote:


> Hi all,
> 
> I have just shot my first roll of IR film (HIE) and have produced some
> really great images. So much so I can't wait to find new material to do it
> again- soon. However, I used a plastic camera body (Pentax MZ5/ZX5) 
which
> allowed a little IR leakage onto some of the frames which prompts the
> following questions:
> 
> 1. Can I wrap the camera body in aluminium foil to make it 
impermeable to IR
> wavelengths? If the sun comes out this week I will try to measure the
> permeability of aluminium foil to IR wavelengths using a hand held
> radiometer, but until then any feedback would be great.
> 
> 2. My other option is to pick up a K1000 body and use my lenses. 
Recently
> various people alluded to the problems with the K1000's dimpled 
pressure
> plate. Can anybody confirm that this problem CAN be surmounted by 
using
> black tape over the dimples?
> 
> Thanks people
> 
> Richard

I have used an Pentax MZ5 with HIE and not had a problem with infrared 
from sunlight penetrating the plastic body, I simply used black PVC tape 
along the back light seals, but later doubted this was necessary. 
However the cut-out on the film pressure plate (this is present even if a 
data back is not fitted) always became visible as a rectangle on the film. 
HIE rated 400 ,processed agfa Rodinal.  This can be solved by cutting a 
rectangle from 120 film backing paper and with thin (non permanent! the 
type of adhesive used on 'post it' notes) double sided tape placing it 
over the pressure plate.(obviously black side outwards!)
Another idea - Someone from Pentak U.K . showed me how easy it was to 
unclip the pressure plate from the camera. This would allow a permanent 
blocking of the rectangular cut-out from behind the plate followed by 
filling in from the front with a kind of hard black wax, they suggested.

Cameron Shaw.



------------------------------