Date sent: Wed, 15 Sep 1999 10:00:11 -0600 To: infrared@a1.nl From: Ken Sinclair Subject: Re: Wisner 4x5 Traditional Send reply to: infrared@a1.nl >Wow, that's completely the opposite of my experiences I've had! I'm just >baffled by the results I'm getting. I've gone through 1 box of HSI B&W and >every negative has been scratched and fogged. I've solved the scratching >problem by processing only one sheet at a time in a 5x7 tray, but each sheet >has heavy fog on each end of the narrow side of the film and lesser fog on the >5 inch edges. > >I've used three different types of film holders, Lisco, Fidelity and Riteway >with identical results. Regular film shows no sign of fogging so the light leak >is IR. Therefore I suspect the bellows. I can use the IR bellows with regular >film and get no fog. I guess my next step is to wrap the entire bellows >assembly in aluminum foil and tape it to the front and rear standards. If that >doesn't stop the fogging then I would think that the rear standard leaks light. > >Thanks for your help. > >Don Bryant Don, In many instances the fog you are obtaining are the result of IR "leakage" through the felts when you remove the darkslide. I have on a few occasions, taken to withdrawing the darkslide to clear the film and just pushing it back in after exposure. I remove the holder and place a piece of masking tape over the darkslide/holder to provide for accidental re-exposure. If you can be "quick" on the draw.. place either your hand or a spare darkslide over the filmholder "end" to shield the felts. Ken [||/\/\/\/\/\/\|| Ken Sinclair RBP, FBPA [|| ||-| Applied Photographic Services [|| || | Lethbridge, [|| || | Alberta, Canada, [|| ||-| (403) 381-1654. [||\/\/\/\/\/\/|| photo1@telusplanet.net _0___________0______ |__________________ | O FROM: "AWB" SUBJECT: Re: IR safe film holders DATE: Wed, 25 Oct 2000 14:01:27 -0700 ORGANIZATION: Posted via Supernews, http://www.supernews.com NEWSGROUPS: rec.photo.equipment.large-format john at nova wrote in message news:8p5ju8$s79$1@Urvile.MSUS.EDU... > Some time ago a post mentioned 'IR safe' 5x4 film holders and something > about three 'bumps' or some marking on the holder and/or slide. Can someone > elaborate, please? John at nova, IR (infared) safe is refering to what the material the darkslides is made from. Some phenolic plastic darkslides, like Fidelity or AWB, has darkslides made with anti-infared layers to help prevent infared light from coming in on your film to cloud the film. The "bumbs" or "markings" on a darkslide handle gives you an indication which side was or was not exposed during your photo shoot at the time when you are in the darkroom to develop your negatives. Hope this clears up your questions? Alan FROM: jess4203@aol.com (Jess4203) SUBJECT: Re: IR safe film holders DATE: 26 Oct 2000 02:06:10 GMT ORGANIZATION: AOL http://www.aol.com NEWSGROUPS: rec.photo.equipment.large-format I have no idea whether this is true or not, but I read the earlier posts and one of them did state that the darkslides with five bumps were infared safe, while those with three were not. Obviously one ought to test those five-bumpers to see if this is really the case. HTH, Roy FROM: dickburk@ix.netcom.com (Richard Knoppow) SUBJECT: Re: IR safe film holders DATE: Thu, 26 Oct 2000 05:09:27 GMT ORGANIZATION: MindSpring Enterprises NEWSGROUPS: rec.photo.equipment.large-format jess4203@aol.com (Jess4203) wrote: >I have no idea whether this is true or not, but I read the earlier posts and >one of them did state that the darkslides with five bumps were infared safe, >while those with three were not. Obviously one ought to test those >five-bumpers to see if this is really the case. > >HTH, >Roy This is correct for "Riteway" and Kodak/Graflex holders. Five bumps mean the darkslide in IR opaque, three bumps that it is not. This convension has been in use for at least sixty years. Other manufacturers may not have a code although all have some feelable marking on one side of the darkslide. --- Richard Knoppow Los Angeles, Ca. dickburk@ix.netcom.com