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  1. #31

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    Movie projectors put out lots more heat than the average slide projector, which has a fan to whisk the heat away. I wouldn't use a slide projector with a broken hot mirror, which reflects IR but lets visible light pass, but 1 minute in front of the bulb shouldn't affect it too much. An hour, on the other hand, according to the Wilhelm Institute, would fade Kodachrome, where the Ektachromes and Fujichromes can spend 2.5-3 hours in the projector before they get a similar amount of fading.
    ME Super

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    There are eight ways to put a slide into a projector tray. Seven of them are wrong.

  2. #32

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    Quote Originally Posted by StoneNYC View Post
    I left a Kodachrome slide in my window for a whole year I see the affects of light on it, it seems fine... It's a direct sun window getting hit at least half the day.

    I'm not saying that a projector won't do damage just surprised the bulb would after only 1 minute.

    Also I would agree that duplicating it would probably be the smart move

    Dwayne's Photo still does it I believe.
    Yes, Dwayne's still does it. A duplicate from a 35mm slide is US 50 cents, but from a negative or a digital file is US$1.10. I just got some back from them yesterday that I'd scanned negatives of and sent to them. B&W slides from Rollei IR400S look pretty cool
    ME Super

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    There are eight ways to put a slide into a projector tray. Seven of them are wrong.

  3. #33
    AgX
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    Quote Originally Posted by ME Super View Post
    I wouldn't use a slide projector with a broken hot mirror, which reflects IR but lets visible light pass,...
    I assume typically it is the other way round, with visible light being reflected. Anyway, a good designed slide projector cools by means of air stream the lamp, the lamp housing, the IR filter in the lighting beam and the slide itself.

  4. #34
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    So lets see, they last forever if you don't look at them with light. However, its OK to look at them with the lights off.
    Items for sale or trade at www.Camera35.com

  5. #35

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    Quote Originally Posted by AgX View Post
    I assume typically it is the other way round, with visible light being reflected. Anyway, a good designed slide projector cools by means of air stream the lamp, the lamp housing, the IR filter in the lighting beam and the slide itself.
    From wikipedia (http://en.wikipedia.org/wiki/Hot_mirror): "A hot mirror is a specialized dielectric mirror, a dichroic filter, often employed to protect optical systems by reflecting infrared light back into a light source, while allowing visible light to pass." A cold mirror, according to wikipedia (http://en.wikipedia.org/wiki/Cold_mirror), "A cold mirror is a specialized dielectric mirror, a dichroic filter, that reflects the entire visible light spectrum while very efficiently transmitting infrared wavelengths."

    I looked it up after I saw your post because I thought you were right and I had it backward. No biggie 'cause I'm not designing, building, or repairing slide projectors, just using them.
    ME Super

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    There are eight ways to put a slide into a projector tray. Seven of them are wrong.

  6. #36
    AgX
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    You are right, but to my understanding projectors typically use cold mirrors to drain the majority of IR-Radiation at the lamp stage.

    Hot mirrors are used to even highten the temperature of the filament in a halogen lamp to make it more effective.

  7. #37
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    Quote Originally Posted by winger View Post
    ... I was initially more worried about the possibility of the slide catching on fire or melting while being projected - which is probably from somewhere in my quite active imagination anyway...
    You might have seen melting movie film, because the small frames needed such intense light to fill a screen that if you didn't keep the film moving (if it got stuck) most projectors would melt the film.

    Doesn't happen much with 35mm.

    But, I had a Bell & Howell Slide Cube projector which melted one of my favorite slides. The darn thing was engineered only for square corner cardboard mounts and had real trouble feeding the later round-corner mounts. But it ran hotter than any other projector.

    Still, I'd rather show for 20 seconds - a real slide on a real screen... and have that experience. Than miss out because I was worried about ruining the slide.

  8. #38
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    Quote Originally Posted by ME Super View Post
    Yes, Dwayne's still does it. A duplicate from a 35mm slide is US 50 cents, but from a negative or a digital file is US$1.10. I just got some back from them yesterday that I'd scanned negatives of and sent to them. B&W slides from Rollei IR400S look pretty cool
    I'm confused, what's Rollei IR400s? I've seen Rollei Retro 400s and Rollei IR400

    But not combined, and the internet doesn't seem to give me an answer... Thanks.

    Wonder why they charge more? I hope they aren't personally scanning and then using their scan to project into the new slide, because their scans are horrible LOL

    Their prints are beautiful if you send them files digitally, but unless they've improved, the last Kodachrome slide I got scanned from them (2010) was just horrible.

    Thanks.


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    ~Stone | "...of course, that's just my opinion. I could be wrong." ~Dennis Miller

  9. #39
    AgX
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    Quote Originally Posted by StoneNYC View Post
    I'm confused, what's Rollei IR400s? I've seen Rollei Retro 400s and Rollei IR400

    But not combined, and the internet doesn't seem to give me an answer...
    Maco themselves started quite some confusion in the past by seemingly labelling the same Agfa 400 ASA film differrently for their own Rollei range. They even produced a Rollei datasheet that contained figures/graphics from two different Agfa data-sheets.

    But so far no "IR 400S" designation turned up...


    (Long ago Agfa made a 400 ASA film on PET base but without IR-sensitization.)
    Last edited by AgX; 10-18-2013 at 04:07 AM. Click to view previous post history.

  10. #40

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    The "S" in IR400S denotes a synthetic base. I'm thinking that the Retro 400S and the IR400S and the IR400 are all the same film. Incidentally, I'm told that the Rollei Retro 80s also has a bit of IR sensitivity - out to 750nm, where I think the IR400 goes out to 820nm before the sensitivity drops to zero.

    I got a slide of the IR negative through a hybrid process which is verboten on here. DR5chrome can reversal process this film, but I haven't had the nerve to send it to them yet as they're saying they only see partial IR effects, where it looks like I'm getting full IR effects with my film by using a cheap Chinese 720nm filter and sending it through a non-reversal process.
    ME Super

    Shoot more film.
    There are eight ways to put a slide into a projector tray. Seven of them are wrong.

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