On 28 Mar 2003 at 16:10, Geir Aalberg wrote: > Interesting. Does this mean that if one use it in a camera with one of > these film pressure plates with "bumps", you're likely to see reflections > of the bumps on the prints? (I was told in darkroom class this was the main > point of anti-halation coatings.)
Anti-halation coatings prevent scatter and reflections and under certain conditions the dimples in pressure plates such as those found in some pentax cameras can lead to ghost images on film. A simple solution is to temporarily cover the pressure plate with some backing paper from 120 roll film. > On a sidenote, I just picked up a roll of HIE at Jessops in London, who > warned that it would get fogged by almost anything - including mobile > phones. Not sure how much truth there was in this, but sending it through > the security check scanner didn't seem particularly appealing. So I took a > chance and put in my jeans pocket, and, hey, no beep. Come to think of it, why > should it? After all the casing is made of aluminium, which is non-magnetic. So > from now on I'll forget insisting on hand searches - I'll just stuff them down > my pants. At least until I get banned from the lab. Mobile phones emit microwave energy which is way outside the spectrum to which HIE is sensitive (IR, visible and near UV) so there will be no chance of exposure. The x-rays machines used to scan check-in baggage can ruin films in one pass but the hand luggage scanners are fairly low emission and as the effect is cumulative you would probably have to pass a new film through four or so times before you could measure a density change with a sensitive densitometer. Pre-exposed films will likely be effected to a greater degree per x-ray exposure. Hand checks usually mean the end for HIE, passing them through the hand luggage x-ray is a far safer bet. Even showing security people the exposure warning message on the lid of the canister doesn't put some of them off opening them for inspection :-( You were simply lucky not to get pulled up when you walked through the metal detector. The film carts are metal and the metal detector detects metal, the sensitivity was obviously wound down. Commercial 35mm film carts including HIE are made of mild steel, the foil sleeve on 120/220 roll film are aluminium and can be detected however most use plastic spools so if you remove them from the package then they are extremely likely to pass the metal detector without triggering the alarm. APS films are the only common film types that use a plastic container (as did the old 110, disc and 126 carts). Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications.html Pentax user since 1986 PDMLer since 1998
