Double sided tape for long exposures

[QT Luong]

To do hours-long exposures (such as star trails at night), I have found it is necessary to find a way to prevent the film from moving. Since the regular double-sided tape is too sticky, in the past I've made my own by gluing a piece of such tape with post-it (TM) tape. Still, the problem I had was that loading and particularly unloading film became difficult, since the film cannot slide anymore.

Is there more suitable adhesive material ? How do you handle the film ?

[cyrus]

You can reduce the stickiness of the double-sided tape by sticking it onto and removing it from your jeans a couple of times before you use it on your film.

[Vaughn]

I got a couple product samples from 3M -- the tackiness varied from low, med and high. I used a tape that had high on the back and medium towards the film. I do not have the product numbers anymore.

Works, but it was still a hassle to load and unload -- and if the film is left in the holder too long, some adhesive is left on the back of the film (keeping the anti-halation layer from washing off.)

Lost a 11x14 neg to the neg popping last week-end...sigh...

Vaughn

[Leigh]

Hi Tran,

Sinar makes a film holder with a permanent adhesive for holding the film that will do what you want...

provided you have deeeeeep pockets. :D

- Leigh

[vinny]

You need Repositionable ATG tape made by 3m. Tom paiva uses it as well as drew wiley, who gave me the idea. 5 small pieces on an 8x10 holder should do it.

[vinny]

that's 3M 928 ATG tape to be more specific.

[Jimi]

I thought about this link when I saw the question:

http://www.deadbread.com/crumbs/vac.html

Maybe a bit high-tech compared to tape, but I guess it is an interesting read anyway.

[Drew Wiley]

I have posted repeatedly on this subject. You need to make some dedicated holders
by trimming away the fins which hold the film itself in position. Then the film can
simply be placed placed directly on the reusable ATG tape noted above. It will stay
flat for ten years if necessary.

[Jim Noel]

I don't like tape on the film. The solution is to focus the camera, cover it, especially the lens, with the dark cloth and remove the dark slide. Wait 5-10 minutes and then uncover the lens and make the exposure. This allows the ambient atmosphere to penetrate the film and make it pop if necessary prior to making the exposure. No more movement in the image.

[Steve Gledhill]

Two weeks ago I made three 8.5 hour exposures of star trails in Canyonlands NP - my first. I didn't consider the matter raised here. :(
I'm just about to develop the film so I'll find out shortly if the sheets popped or moved ...

[Bill McMannis]

Have you tried a Grafmatic? The couple I have hold the film quite securely.

[QT Luong]

Thanks vinny for the suggestion. Looks like a good ready-made version of what I've been using. Drew, this sounds a good idea. What tool do you use to cut the fins ?

[Drew Wiley]

I just use a good stiff sharp blade on a utility knife, with a 12-inch steel straightedge.
The plastic fins on a typical Lisco or Fidelity holder will trim right off. Nothing to it. Then I check for any leftovers burrs or sharp edges which need a bit of further trimming or sanding. It obviously helps to practice first with a beat-up older holder.

[tgtaylor]

Ever since switching from readyload holders to Toyo cut film holders (4x5) I have never had a problem with film shift during long or multiple exposures where the 2d exposure is taken 1 to 2 hours later. I haven't tried such exposures with 8x10 yet but my 8x10 holders are Fidelity Elite and they don't hold the film as snuggly as the Toyo 4x5's do.

Thomas

[Steve Gledhill]

Two weeks ago I made three 8.5 hour exposures of star trails in Canyonlands NP - my first. I didn't consider the matter raised here. :(
I'm just about to develop the film so I'll find out shortly if the sheets popped or moved ...

I've posted the results here (http://www.largeformatphotography.info/forum/showpost.php?p=790812&postcount=263) - two good :) i.e. film didn't move, but the third displays all of the problems of moving film :mad:

[vinny]

Thanks vinny for the suggestion. Looks like a good ready-made version of what I've been using. Drew, this sounds a good idea. What tool do you use to cut the fins ?

You don't have to remove the fins, it would make things easier but not necessary. I only know this because of a friend who is using the tape (in 8x10 holders) hasn't done so, just pop the film out.

[Steve M Hostetter]

Try using polaroid film 8x10" I know is held in tight

[patrickjames]

I would agree with the mention of a Grafmatic above. They hold the film very securely along three sides if adjusted accordingly.