Datasheet mistakes

[Garbz]

Has anyone every come across any films where it appears the datasheet is just flat out wrong? Either I have just found one or I am misinterpreting what it is saying.

A friend and I were using Efke IR820 film. I have no idea how he shot or developed other than that we both used different filters and different developers but his negatives turned out just as bad as mine when we were finished.

Firstly the datasheet for this film recommends a filter with a 715nm IR pass to be degraded 4-5 stops ISO6 instead of ISO100. When I finished with my developing despite bracketing there was only 1 photo (completely rich in IR light naturally) that was acceptable, and even that one was bracketed to ISO3. I get the feeling that these values in the datasheet are too conservative and the film should really take a 5-7 stop hit with the filter in place.
More so the old Kodak HIE (RIP) had a much longer sensitivity in the IR range and recommended a 4-5 stop hit with the filter, so really I doubt it can be right.

Then in developing I had another problem. Fixing was not an issue surprisingly the datasheet was spot on that the clearing time was approximately 1min from my tests so I fixed for 3min as per recommendation.

But developing in Xtol 1+2 for 16min at 20degrees can't have been right. I even monitored the temperature during the 16min (room temp was about 26 degrees) and by the end the tank was 23 degrees, but I still did the whole 16min so if anything the film should have been overdeveloped.

The negatives I got out (even my reference photos taken at ISO100 with no filter) were incredibly thin.

Is datasheet errors a likely scenario? I rule out the chemicals since I used the Xtol only once in stock state 1 week ago, otherwise it is fresh.

Here's the only picture that came out, and despite looking good it took quite a bit of effort in photoshop to correct it:

 

[ann]

first, IR film is very tricky and needs lots of testing.

secondly, yes, data sheets can be wrong. the most classic case was several years ago when kodak changed something with trix. the specs now indicated that with hc100 solution b that the development time was (can't remember if it was 3.5 or 4.5 minutes) . People who had spend a life time using this combination went "nuts".

For the most part, they just continued to used their tested times pre changes with the film. I know several people talked to customer support who indicate there had been an error, but nothing offical ever came from Kodak.

I haven't checked the spec sheet lately

 

[Garbz]

Yeah I know IR is tricky, but I have never had a problem with Kodak HIE . Grrr it's overcast today. I was looking forward to trying a second roll at ISO3 and developing at 22 or 23 degrees instead.

 

[Garbz]

Yeah must have been datasheet errors or something. I just used another roll of this film this time shooting at ISO3 not ISO6 (a 5 stop hit from the filter rather than a 4), and developed in Xtol 1:2 for 14minutes at 24 degrees. Datasheet recommends 13 minutes at 22 degrees.

Every single shot on that roll turned out and quite of lot of them are absolute gold.

 

[Flash Harry]

Garbs

Digitaltruth Photo

Dev times etc with all film/chemicals its giving 14 mins at 20degrees iso 4 for your combination, I've used this chart for years and it has never been wrong up to when I changed over to digi. H

 

[Garbz]

Those figures were for 1:1 xtol dilution. I used a 1:2 which seems to be pulled from the datasheet itself.

But thanks I didn't even think to look up that chart before developing. I have only used it on the occasion where I didn't have the developer listed in the datasheet.

Photos are now posted: http://www.thephotoforum.com/forum/...le-heads-lighthouse-infrared.html#post1567502

 

[Flash Harry]

I spent my last couple of weeks in OZ in an apartment not far from there, Coolangatta/balinga beach. H