ground glass...question

[michael2]

hello
i have spent a lot of time reading this super8 thread and i have not found the answer to a very simple question:

I just aquired a (very) expensive super8mm cam in england at super8sound pro8mm.(refurbished beaulieu 4008)

Wether it was a good idea aquiring it there or not is not really right now the question because it's done. The problem is that after a test with k40 i was expecting the sharpest image possible...but i received a film that was totally soft as far as sharpness and with a huge vignette on the right side of the image (using a zoom beaulieu 8-64 + wide angle adapter). The test was done in the best rules: steady shot (no motion blur), a carefull adjustment of the diopter to my eye, and then focusing before the shoot very carefully at full aperture on the ground glass..

The film shot with the pro8mm cam was far less sharper than another test i did with a "street- bought" cheap elmo camera.

After a call to super8mm I was told (but the person i talked to didn't seem so sure) that my unsharpness was due to the fact that i had done the tests with the ground glass NOT retracted from the lens (there is a knob that permits to retract it), and i was also told that the vignette was due to the fact that my 85 filter had to be in front of the wide angle adapter and not in beetween the zoom and adapter...

Maybe that it is very obvious for super8 shooters that this ground glass has to be retracted
during the shoot, but i am suprised i never saw it mentionned anywhere.

Could somebody confirm that this ground glass has to be removed with the knob before the shoot to get optimal sharpness.

And that the particles of light, before "hiting" the film, go through the ground glass (if it is not
retracted??) which could explain my loss of quality.

Thank you in advance for your answers.
Of course i will test again with that procedure. But it will take a few days before i get the answers (film processing etc...) and i am very impatient to know whats going on.

michael
(mr "sharpness" problems...and please don't tell me to shoot with 16mm!)

[cameraguy]

Originally posted by michael2:

Could somebody confirm that this ground glass has to be removed with the knob before the shoot to get optimal sharpness.

And that the particles of light, before "hiting" the film, go through the ground glass (if it is not
retracted??) which could explain my loss of quality.

<font size="2" face="Verdana, Helvetica, sans-serif">No! The light going to the film is not affected by the ground glass. Take the lens off and you can physically touch (carefully) the ground glass screen to the right of the mirror and you'll clearly see that it is not in the lens or the path of light that hits the film. The only benefit to retracting the ground glass is that the viewfinder image is a little brighter without it.

A refurbished Beaulieu 4008 will shoot excellent footage. If it doesn't then make Pro8mm fix it for free!