Kentmere 100 Cartridge light leak (?)

Recently shot (first time) some Kentmere 100 135. In an Oly 35RC, but that is immaterial as seen below. After ~12 frames, cut the film in the darkroom and developed. Result below.

Further down the strip (to the left) the banding progressively disappears and some frames were usable. Light leak from a known good camera?

To be sure, I took the cartridge with the remaining film and left it for a few hours on a table, indoors, cloudy weather, never direct sun. Something I did without thinking in the past without any negative consequence. For good measure, I brought the cartridge close to a fluo tube for a few seconds. Then loaded some film in a tank and developed. Stripes again. No camera involved this time. See below #2. But maybe the part bringing the cartridge close to a fluo tube was excessive? So repeat, indoors, no direct sun a few hours, load, develop. See below #3 (with possibly some tail of the #2 experiment).


Do you agree with y conclusion that we are seeing a light leak at the cartridge lip?

On https://www.ilfordphoto.com/product-feedback/ dutifully filled the product feedback form https://uk.surveymonkey.com/r/PFFormHTL providing the images as feedback.
That was 18-Jan. On 30-Jan, sent a kind reminder via the contact form https://www.ilfordphoto.com/contact-form/
Based on reports on photrio of users having problems with Harman products, I would have expected them to be more responsive.

There was a thread a couple of months ago. I think @logan2z had exactly that problem with some Ilford film - Ilford admitted to him that some of a particular batch of cassettes were faulty and sent him new film. Maybe someone could provide you with a direct email address instead of the online form? Your fogging looks identical to his.

It's light piping in the base, Kentmere does not have the same level of anti-halation treatment as Ilford films - and Ilford have been clear about this and other measures used to make Kentmere as cheap as possible. I've had it happen with K400 if you aren't careful about unloading in subdued light - can't give you an EV number though.

At the end of the day, people don't realise how much of the expensive bits of film manufacture are to do with preventing the end user screwing up, no matter how careless they are.

See this post in the thread I mentioned. Ilford admits it is a problem with the light-tightness of the cassette.

And I would assume they couldn't actually track the use of the faulty cassettes, so some will likely be showing up in various types of Harman film for a while.

@Don_ih Thank you. Comforting to learn I did not "screw up". Just @logan2z appears to have had a response within one week. I cross fingers.

Lachlan Young said:

It's light piping in the base, Kentmere does not have the same level of anti-halation treatment as Ilford films - and Ilford have been clear about this and other measures used to make Kentmere as cheap as possible. I've had it happen with K400 if you aren't careful about unloading in subdued light - can't give you an EV number though.

At the end of the day, people don't realise how much of the expensive bits of film manufacture are to do with preventing the end user screwing up, no matter how careless they are.

Click to expand...

How would light piping from the outside jump over (or pipe through) ~5cm of film left intact and deposit a localized strip of insolation? I would expect piping to extend continuously and gradually attenuate from the exposed leader into the nominally unexposed film.
I'm aware of the limitation of Kentmere films. As I wrote in the OP, this was the first time I shot Ketmere 100. An experiment after decades of FP4 and APX100 being my go-to medium-speed films.

bernard_L said:

@Don_ih Thank you. Comforting to learn I did not "screw up". Just @logan2z appears to have had a response within one week. I cross fingers.

Click to expand...

Your issue does look very similar to the one I experienced.

If you aren't getting a reply to your inquiry using the contact form on Ilford's site, you might want to try emailing technical@harmantechnology.com. That is the email address from which I received responses to my inquiry.

Good luck, let us know how things turn out.

bernard_L said:

How would light piping from the outside jump over (or pipe through) ~5cm of film left intact and deposit a localized strip of insolation? I would expect piping to extend continuously and gradually attenuate from the exposed leader into the nominally unexposed film.

Click to expand...

the classic "light pipe Effect" will result in the light coming out at the perforations., so black band around the perfs.

the roll is about 1 inch in diameter - so repeated fogging at PI inches would be the light trap.

Update. After sending an email to technical@harmantechnology.com, as suggested by @logan2z, I got a response from a nice lady who wrote to me on 25-Jan but had her message bounced by my mail server for an unclear reason.

She wrote that it's a known issue, but a rare one. She also wrote that Harman would send replacement films. When I pointed out to her that the three tests that I documented were repeats from just a single cartridge, she replied don't worry the films are already on their way.

I was almost surprised to receive a response

• which is positive
• from a human being

That surprise says something about the times we live in; try arguing about a hiccup at eprey?

Anyway, kudos to Harman (aka Ilford).

They seem to always try to address their customers' concerns. They're definitely a respectable company.

Agreed on them being good with addressing problems. I've shot a decent amount of Kentmere 100 and 400 in 35mm and did not get any light leaks. I did get mottling once on a whole fresh batch of HP5+ in 120.

I always treat any film as leaking light to be safe - 35mm and 120/220 goes straight into black canisters when it's done if I have any, and stays in the camera until I get indoors if it's the last roll of the day. On trips abroad with too much film to put into canisters, putting them in a dark pocket of your bag works.

bernard_L said:

I got a response from a nice lady who wrote to me on 25-Jan but had her message bounced by my mail server for an unclear reason.

.

Click to expand...

A Kodak server perhaps?

pentaxuser