S8mm projector - clogged film gate?

[megalith6]

hi,

i have a Chinon 'Universal 8' projector [img]graemlins/film.gif[/img] . i noticed that the edge of the projected white rectangle - with no film being shown - was fuzzy. an inspection of the rectangular 'film gate' behind the lens showed it was fluffed up with dust, so i cleared it with a couple of puffs from a canned air aerosol ... so far so good -

however, there is still a horizontal, dull blur extending down from the top left of the projected light source [img]graemlins/idea.gif[/img] - i have no idea what is causing this - i can't see anything else getting in the way of the film gate?

[img]eek.gif[/img]

any clues as to what might be obscuring the edges of the projection field, please?

thanks,

[BolexPlusx]

Sounds like a hair!

Since it's blurry the likelyhood is it's recessed inside the gate and maybe a little harder to see when you're looking at the gate.

If it was up on the film plane it would be more in focus.

<font color="#a62a2a" size="1">[ October 16, 2005 07:01 PM: Message edited by: BolexPlusx ]</font>

[megalith6]

Thanks BolexPlusX,

Is it possible to get at this rectangle - to get a closer look / clean it with a brush: i have a reprint of the original manual, but it doesn't go into any detail re maintenance?

also, obviously this is an old machine: is there anything i can tweak to minimalise film-splice-jump, please?

Thanks,

ric

[BolexPlusx]

Unfortunately the best place to start smoothing out splices is with the splices themselves (unfortunate because this makes the fix spread out over every splice you've ever made!). Tape or overlapped cement splices momentarily change the thickness of the film passing through the gate: kind of like introducing a speed bump the pressure plate has to climb up and then down.

I went to the Bolex bevel splicer because I get some of my films sound striped and the smooth splice holds the stripe much better, however the passage through the gate is noticeably smoother and quieter too.

[megalith6]

hi,

well, i invested in a Bolex splicer about a year ago, so i suppose this is the ideal excuse to put it through its paces? i have cement, i also have [img]rolleyes.gif[/img] superglue - since the Super 8 is interspliced with Fuji Single 8. i am sure this is not a 'first', but i haven't heard of anyone trying this experiment before?

i am really looking forward to getting to grips with this splicer, i have to admit!

any tips, please? [img]graemlins/wonder.gif[/img]

ric

[BolexPlusx]

The most critical part of the whole shebang is the instruction sheet! There is about an eight step sequence that has to be followed.

It's a little like going to a manual transmission car from an automatic: in theory it's complex (maybe even a little intimidating!), but once you've done it enough it's second nature.

Maybe grab a yard of scrap film, cut it in about ten places and splice it back together. That's how I got started. If the splices are right, there are no air bubbles visible, and will hold together given a 180 degree twist an inch either side of the splice.

I find my splices are better if I put a little finger pressure on the right hand door for about 20 seconds while the cement sets up.

Cleanup is critical, this creates a lot of dust and it looks awful if you don't get it off the film. Isopropyl alcohol on a lint free cloth does a good job.

PS Once I started using it for real, I've never, ever had a splice fail.

I'd be a little reluctant to use super-glue because you may wind up gluing the doors of the splicer shut. (am I sure?...no!)

I've heard that acetate and polyester films don't intermix very well because the difference in thickness causes the focus to change. (am I sure?...no!)

You could try it and perhaps debunk an old myth, but I'd still be wary of the super-glue!

A friend of mine in the UK uses some Loctite cement for polyester to polyester splices, but I don't think he's done poly to acetate. (I'll ask!)


My Bolex splicer sat in the box a whole year before I tried it too!

[megalith6]

Hi BolexPlusx,

--------------------------------------------------------------------------------
BP: The most critical part of the whole shebang is the instruction sheet!

no worries - the original instruction sheet came with the splicer

BP: Cleanup is critical, this creates a lot of dust and it looks awful if you don't get it off the film. Isopropyl alcohol on a lint free cloth does a good job

isopropyl - from a pharmacist?

but would this not affect the film emulsion, please - why not just carefully vacuum and brush away the residue?

BP: I'd be a little reluctant to use super-glue because you may wind up gluing the doors of the splicer shut. (am I sure?...no!)

this is a worry - but i really want to sort the film jumps; i will certainly use something else if it might do the job (there 'must' be something?)

BP: I've heard that acetate and polyester films don't intermix very well because the difference in thickness causes the focus to change. (am I sure?...no!)

true enough, but the difference is an 1/8 turn of the focussing control on my projector - i can live with that...

BP: A friend of mine in the UK uses some Loctite cement for polyester to polyester splices, but I don't think he's done poly to acetate. (I'll ask!)

i would be greatly onliged, BolexPlusx, this is a steep learning curve for me!

BP: My Bolex splicer sat in the box a whole year before I tried it too!

this gives me heart!

many thanks,

ric


[img]graemlins/film.gif[/img]

[BolexPlusx]

Yes!,

Good ol' Isopropyl Rubbing alcohol, the higher the percentage the better. It is actually harmless to film, increases the grab of the cloth on the dust, lessens the friction of the cloth and dust on the film, and evaporates very quickly to prevent spotting (you just need to be patient and take your time: not so fast that that it's still wet when the film goes back onto the reel).

Considering that film is sometimes soaked in gasoline (petrol to you)to remove lubricants before it is sound striped, it's sterner stuff than you'd imagine.

I've momentarily lost contact with my friend who uses the loctite adhesive to splice (usually means his PC has been virussed), but I will find out the number for you and post it here.

Yes, because I was intimidated by the complexity of the instructions, I continued to use my overlap splicer long after I got my Bolex. When it was really quiet I swear I could hear it laughing at me!

[megalith6]

BP:- Good ol' Isopropyl Rubbing alcohol, the higher the percentage the better. It is actually harmless to film, increases the grab of the cloth on the dust, lessens the friction of the cloth and dust on the film, and evaporates very quickly to prevent spotting (you just need to be patient and take your time: not so fast that that it's still wet when the film goes back onto the reel).

no luck at the pharmacy/drug store, but Widescreen recommended 'Fotospeed FC50 Film Cleaner' which seems to do the same job?


BP:- I've momentarily lost contact with my friend who uses the loctite adhesive to splice (usually means his PC has been virussed), but I will find out the number for you and post it here.

many thanks - i found Loctite - it is a form of super glue over here, but in two grades, fluid and gel

i wonder if spliced, cemented film can be sandwiched between ultra thin paper, to protect the splicer surfaces?

BP:- Yes, because I was intimidated by the complexity of the instructions, I continued to use my overlap splicer long after I got my Bolex. When it was really quiet I swear I could hear it laughing at me!

my last (first) film used to jump on my projector, but when it was run through a different projector (Brighton Cinematheque) it didn't jump once; so i don't think my tape-splices are that bad? - but the Chinon sure doesn't approve! so i have no option but resort to the Bolex - which i am actually really quite looking forward to!!

[img]cool.gif[/img]

[megalith6]

had another look at that film gate - it's not dust, there appears to be a fractional misalignment of the film gate itself, which is a sandwich of metal plates ... so the top edge bleeds light into where it should be black - which makes the crisp edge appear to obtrude into the light rectangle - apart from that, it is difficult to see what is going on since the clearance on the side of the projector, through which you peep, is about 1/4 inch

blasting the interior with canned air has helped, but the fuzzy top edge is something technical - it's not that bad, just irritating...

i spliced some spare super 8mm film with the Bolex - mine does work - the resulting film strip went through the projector twice: the film did not break.

...........................................

criticisms - it was sometimes difficult to cut the film, after bevelling it - especially Single 8.

you can use loctite to splice Single 8 but it ain't easy and, as i say, Single 8 doesn't really appreciate the Bolex - which will actually tear at the film while bevelling it, if you are not careful.

............................................

the first time i put the film through the projector it chugged its way through 50 feet without jumping - apart from the very last splice onto the white lead-out;

i inspected this, then put the film through again - this time it jumped after the lead-in and at least once in the middle of the film: same film, same projector, image jumping for no apparent reason?

still, on balance, the Bolex is an improvement over the tape splicing: i must have a very temperamental projector, is all i can put it down to?

[img]graemlins/wonder.gif[/img]

so onto the big day tomorrow - when i try out the Bolex on the tape-spliced film: wish me luck!

[img]graemlins/film.gif[/img]