problem with new portra 400 in 500c/m

[sfcole]

<p>I'm wondering if anyone has had a similar problem: I've put many different types of 120 film through my 500/c/m (new-style A-12 back), and the last couple of rolls of new Portra 400 have not wound correctly.<br>

The problem manifests itself after a few frames when it becomes obvious something is amiss in frame advancement, and at the end of the roll, the entire roll is sitting loosely around the plastic core, unprotected from stray light. I'm fastidious with loading, making sure the leader goes on straight and tight. This has not been a problem with other films, including TMYii, and Fuji negative films. Could there be a manufacturing defect with the new Portra, something to do with how the film/backing are aligned?<br>

thanks</p>

[bob_sunley]

<p>Could be the leader is a little slippery, try taping the leader to the core for a test. I've not had any problems with in my 645.</p>

<p> </p>

[LenMarriott]

<p>Scott, Could the problem be with the back's tensioning spring which assures tight rolling of the film? Been there & done that with one of my backs for my Bronica SQ Ai. Re-tensioning said spring ( luckily an easy fix) solved my problem of loosely wound film. Let us know how you make out. Others may face the same dilemma. Best, LM.</p>

[sfcole]

<p>After getting the rolls back from the lab, I've noticed that the funky Portra rolls do indeed seem to be defective, and have a crimp running along one edge of the roll. The rolls of successful Portra had no such crimp. Now the question is whether to use the rest of the rolls of Portra...</p>

[bob_sunley]

<p>You mean a rolled up lip on the edge of the film itself? Defective take up spool, maybe? I had it happen once, a slightly bent metal take up spool.</p>

 

[sfcole]

<p>Bob,<br>

No, I mean a crimp along the entirety of the film edge, not just the leading edge. The take up spools change each time and are plastic.<br>

Scott</p><div></div>

[jim_bielecki1]

<p>Not to get into a "my brand vs. your brand thing," but I suspect the problem may be your back. Over the past few weeks, I've put over 20 rolls of Portra 400 through my Rollei 6006 with no problems. No problems with Portra 160 either.</p>

<p> </p>

[q.g._de_bakker]

Hard to say what is causing this. I have used Portra without such problems, and there should indeed not be such problems, of course.<br>Wouldn't know what would cause this, really.<br>Could indeed be a batch thing, and you could try Portra of another batch number.<br>The film may be wound slightly 'askew' on their spools in the factory, or indeed the film not attached 'straight' on the backing paper. The pressure marks on the scan certainly indicate the film is forced against something and not running through smoothly.

[al_bowers]

<p>Scott,<br>

This has happened to me on two instances, once years ago when I misloaded the A12 magazine for my 500CM, and the other time in my Rollei TLR when the feed spool was slightly wider than the alloted length by the magazine (plastic vs metal spool).<br>

In the first case, I failed to release the catch at the edge of the A12 insert pressure plate. The film bound when loaded (not being correctly pulled against the pressure plate) and when the leader mangled up, it bound between the magazine insert and the outer case. The result was creasing along the edge for many frames until the leader and film tore and realigned itself correctly for the last couple of frames on the roll.<br>

In the second case, the feed spool had excessive friction and pulled the leader free.<br>

Your problem sounds like the first issue, but your being fastidious about loading makes me suspect it is something else...<br>

Al</p>

[howard_g._tate]

Hi Scott,

 

Looks like you did not slip the film under the film clamp and so the film will ride over the top of the clamp and cause crimping of the

edge and difficulty in winding on.

 

Regards

 

Howard

[rashed_s]

You have no problem with you Hassy back, the problem with your films real, I do not know what

they are called in English, I refer the black plastic real where the film is rolled on, these one due to

bad storage and high temperature some times they get deformed and they then do not set

uniformly in you back, if the back had a problem the sign will be with all of the type of films and not

one.

[sfcole]

<p>Howard,<br>

Looks like you may have nailed it. I hate to admit it, but after a summer of shooting and even having the instructions, I haven't been putting the film under the pressure plate! I guess I got too used to my Bronica, where I just pulled the film around and that was that. I think this will solve the problem. Having a crimp along an entire roll seems like too big an error for Kodak to make.<br>

Scott</p>

[louisb1]

<p>Phew! This may explain why one of my rolls of Fuji 400H came out the same way. I too thought I might have an intermittent fault with the back but now I come to think of it, maybe I just forgot to make sure the edge was under the pressure plate one time. Has not happened again (yet).</p>

[q.g._de_bakker]

Just so it is clear to anyone who may stumble across this thread in the future and only reads the bit about the resolution of the problem, just a quick correction of the vocabulary:<br><br>The film goes <i>over</i> the <i>pressure plate</i>, but (at one side) <i>under</i> the <i>retaining clamp</i>.<br><br>(The job the retaining clamp does is keep the film away from the shell's edge when the insert is inserted into the shell. Load the film over the clamp, and it will demonstrate that the clamp is a precautionary device, not an absolute necessity. But more importantly, the film will then not lie flat across the pressure plate, so partial unsharpness is a given. And it may - as demonstrated in this thread - even cause physical damage to the film.)