SX-70 Model 3 door on a 680?

[thomnola]

So I'm having trouble with divots and other anomalies when shooting Impossible Project film in my 680 and, after some research, came across a reference to the problem stemming from the fact that the rollers on the 680's are not as tight as the older SX-70 rollers. Has anyone had experience with replacing the door of the 680 with an older SX-70 model 3 door? Do the divot problems disappear? My thinking is that I can pick up a Model 3 fairly cheap and rob the door from it.

 

[AgX]

Why should the effective slits be different? I do not expect a major difference in film thickness.


The slits are regulated in different ways depending on model:
-) with the SX-70 there are distance rings at one roller yielding a minimum slit (0,1 mm, much thinner than the film)

-) with the the 640 the bearings of one roller rest at the axle of the other, the slit is even smaller than at the SX-70

-) at all models the bearing of of one roll is under pressure of a spring that regulates the further widening of the slit when film is inserted

To test slits use blade-type thickness gauges and and insert them in the same position from the inside between the rollers, turning rollers by means of the cogwheel. (With coated rollers this may lead to damage at the coating, one better would use cardboard samples in this case.)
Try to find out about different forces necessary to do so.

In engineering literature there is hinted at bellied rollers at these cameras. This is definitely not the case with my samples.

 

[peteyj10]

Not sure if you're still looking for help on this.....but how old is your film? I have an SX-70 and I have the same exact problems with every shot I've taken and I've chalked it up to old(er) film. One of the flaws with Impossible film is that, even if it's not expired yet, the chemicals start to dry out. I haven't yet tried out the newest formula on my SX-70, but I've heard it's better in that regard.

 

[thomnola]

That particular batch of film was bought at Urban Outfitters. I'm keeping my fingers crossed that IP will perfect the film eventually. When it works, it's beautiful but there are still too many inconsistencies.

 

[AgX]

how old is your film? I have an SX-70 and I have the same exact problems with every shot I've taken and I've chalked it up to old(er) film. One of the flaws with Impossible film is that, even if it's not expired yet, the chemicals start to dry out.

Basically that is a problem one got with the Polaroid films too: the processing gel was losing solvent and also changed viscosity. Beyond expiry time this led to uneven spread between the two halves of the film.

 

[peteyj10]

That particular batch of film was bought at Urban Outfitters. I'm keeping my fingers crossed that IP will perfect the film eventually. When it works, it's beautiful but there are still too many inconsistencies.

It very well could be the film then. I highly doubt Urban Outfitters stores their film properly. They're also probably selling older stock. I went to a dedicated camera store here in Chicago and even they still had the previous generation on the shelves. Does the box say PX680, or does it say Color For Use With 600? If it's a box of PX680, then you have the previous generation of film.

I agree that there are far too many in consistencies. I've gotten divots on every single shot I've taken (16 so far). On the first pack they weren't too bad, but on the next pack they were all over the place, big, small, etc. Additionally, on my first pack, I maybe one picture with the vertical stripe problem. My second pack, every single picture had vertical stripes. And each pack there was at least one shot that came out either all black or all white.

Like I said though, supposedly the current generation of film that just came out in October is a pretty good effort.

 

[Lee Rust]

Getting there...

The post-October batches of Impossible films are greatly improved. That greenish tint in color films is almost gone and the very annoying vertical stripes in SX70 and 600 versions have not (so far) recurred. The new B&W film is fairly contrasty and mostly free of the murkiness and solarization effects of the earlier 'silver shade' formulas. Reportedly the B&W is now less prone to aging deterioration. Development times for B&W are approaching 'instant', taking around 5 minutes for full image emergence. The new color film seems a little faster too, with most of the image visible through the blue opacifier after 20-30 minutes, but it still takes close to an hour to clear completely. I've fitted IP frog tongues to my cameras and they've made a big difference in image consistency, especially with the B&W. The long tongues also keep the ejected print from shooting out onto the ground.

Impossible products are still a work in progress though. The edges of most photos are usually cloudy. Weird discolorations, random spots and bubbles are commonplace. My wife continues to comment that the photos look 'old', but in terms of image quality I think Impossible has definitely progressed from the late 19th to the early 20th century. They've still got quite a way to go before they catch up to where Polaroid left off, but it does look like they'll eventually get there. It's been quite an experiment so far.

 

[peteyj10]

I actually just picked up a pack today of the new formula because of this thread. Fired off a couple test shots, and I didn't get any divots or vertical stripes. It's still a far cry from perfection, but it's definitely a huge improvement over the last batch. I say in a few years the quality will be close to the real deal...but I do kind of hope they keep around some of the old formulations as a "classic" film. Impossible Films through all their different batches definitely have a unique look to them, and sometimes the imperfections add rather than subtract.

To the OP, I suggest ordering directly from the Impossible website, or go to a store that has the new formula. Like I said, the box for the old formula will be PX while the current batch for your camera is just "Instant Film Color (or B&W) for use with 600".

 

[thomnola]

I've had hits and misses with film I've bought directly from IP but I have seen improvements overall. It can only get better so I'll keep using it. Even had the SX-70 I bought in 1979 cla'd and reskinned.