Re: [APML] Electro-Static Discharge and hypered 120 format Tech Pan

[Jerry Lodriguss <jml@astropix.com>]

Hi Steve,

Electrostatic discharge usually looks like lightning marks on the film.

Crescent marks are handling marks from kinking the film while rolling it on 
the reel or some other place in the handling.

As far as ESD during handling, you could try a grounding strap like they 
use when handling computer components.

I'm really surprised you get uneven hypering without the paper backing, but 
even hypering when leaving it on. This seems the opposite of what most 
others have reported. I know people had problems with the old backing 
material outgassing, but I thought they changed the material so that is not 
a problem anymore. That would explain why you don't get problems with it 
present, but it doesn't make sense that you would get uneven hypering with 
it not present... curious.

Jerry



At 10:55 PM 4/4/2002 -0800, you wrote:
>I have found little crescents here and there on some developed hypered 120
>format Tech Pan film that I think are caused by electrostatic discharge
>(ESD) when I remove the paper backing.
>
>So, my question is this: Of those who are hypering 120 format Tech Pan and
>then removing the paper, what are you doing to avoid ESD?
>
>Here are some aspects of the problem I have:
>
>- I must leave the paper backing on when hypering or I get uneven hypering
>of the film. I think this is pretty common knowledge and I have definitely
>demonstrated it by trying. I get "bands" on the film.
>
>- I must remove the paper before using the film because I have a vacuum
>camera back that would be defeated if the paper was left on.
>
>- After hypering, the film and paper are highly dessicated (dry) which makes
>ESD more likely. It's like pulling socks apart after they come out of a
>dryer. Zapppp....
>
>Any suggestions?
>
>Thanks!
>
>Steve...
>
>swalters@att.net
>http://Astrophoto.home.att.net
>
>
>--  APML Archives at <http://astro.umsystem.edu/apml/>  ---
>              Unsubscribe at <majordomo@seds.org>

Photoshop for Astrophotography Book:
http://www.astropix.com/APBOOK/0_PROMO/PROMO.HTM

Astrophotography, Tips and Techniques
for Digital Enhancement in Photoshop:
http://www.astropix.com

--  APML Archives at <http://astro.umsystem.edu/apml/>  ---
             Unsubscribe at <majordomo@seds.org>