Why are some slide transparencies red?

[ADemuth]

My grandmother moved into a retirement apartment and we're in the process of selling her estate. I'm in the process of digitizing the slides my grandfather took of their travels (7,000-8,000 of them!) Every once in a while I'll have a batch of deep red tinted slides. What caused this? My initial thought is that it was my grandfather buying out-dated film. He notoriously pinched pennies with film, something that came back to bite him on several occasions. Furthermore, what are the mechanics for the red tint?

 

[TNcasual]

Not all films/processing is all that stable. It was probably cheap film and/or processing.

When I went through my father's slides I found that any purchased slides (yes, purchasing slides at gift shops/souvenir stores was a thing) usually had the most degradation. I just figured that those slides where cheaply made because they were being produced for a profit.

 

[ADemuth]

That supports my cheap film theory - for some reason he'd cheap out on film, but pay for decent processing - mostly Kodak from the looks of it. Even some Leica processed slides - those are WWII era if I recall. Seeing WWII in color is weird.

It's a shame, because there are some cool shots. I know they can be color corrected to some degree, but I don't have the time or resources for that - I'm already bogged down with manually changing slides in my enlarger. PP will consist of a rough crop, auto-levels, and throw them on an SD card so Gram can look at them on her tablet.

I remember seeing slides for sale when I was a kid. Back then I didn't know slides could be copied, so I thought they just had some dude out there with a bunch of film and a camera taking the same picture over and over again.

 

[Hendrik]

I've encountered this especially with the product of certain inexpensive vendors/processors that used regular movie film negative stock from which slides would then be produced. Negatives and slides, what's not to like? After 30 years or so, the negative stock goes almost entirely red. The slides become red, as well, just a bit less so. The particular outfit my father-in-law used was MSI, IIRC. At the time, he was very proud of his find.

 

[ADemuth]

After 30 years or so, the negative stock goes almost entirely red. The slides become red, as well, just a bit less so.

Anyone know why this is? I'm only vaguely familiar with how color film works, so troubleshooting is way out of my field and a Google search really only turns up results that tell you how to try to fix the red in PS.

I'm glad that quite a few of these slides are in great shape - most of the ones from the war look like they were taken yesterday, and there's a couple of great ones of my grandfather and his buddies in his squadron that are pristine.

 

[tkbslc]

I know they can be color corrected to some degree, but I don't have the time or resources for that - I'm already bogged down with manually changing slides in my enlarger. PP will consist of a rough crop, auto-levels, and throw them on an SD card so Gram can look at them on her tablet.

You don't have to correct them all. I'd just blow throw them when you are done and mark the best ones and fix those.

With 7000 shots, you may want to trim them down to a curated collection of the best 10% anyway. With literally thousands of images, you end up getting overwhelmed and don't appreciate them as much.

 

[ralf-11]

if the same tint, you only need to figure out how to correct one - then apply that to all of them at once

even if not perfect it may well be quite close

 

[Brownie]

All of the above. When I was a kid we visited Hawaii and I purchased a sleeve of 5 or 6 slides taken during the attack on Pearl Harbor. All of them have a deep reddish-orange tint. Recently I used an adaptor and copied them with my G7. Since they were B&W anyway, correction was as easy as hitting a button. Other slides taken by me using who knows what for a camera, probably a 126 because the images are square, have been more difficult to deal with. It takes time and acceptance of the fact that I stink at it.

 

[ac12]

As I recall, Kodachrome had a tendency to fade to redish. The other colors in the slide would fade, leaving the red base.

From memory (not always accurate) color film is in layers, each layer sensitive to a different color (RGB).
So if the Green and blue fade, you have red left.
The degree of fading would result in different colors. If the green faded you have purple.

The other is the processing.

• If the processor screwed up, the colors would come out messed up.
• Using depleted chemicals was one way to screw up the colors.
  • If the processor wanted to save money, he would push the use of the chemicals beyond manufacturers recommendation; so he would process 120 rolls before changing the chemicals, rather than the recommended 100 rolls.
• If the equipment was not properly maintained there could be problems.
  • Cleaning the line means stopping the line, which means no revenue from that line. So rather than clean every 10 days, he may push it to clean every 15 or 20 days.
  • Was the equipment checked and adjusted for temp, processing time, etc.

When I grew up, the Technicolor lab had a bad reputation. They were cheaper than Kodak, but it was almost a flip of the coin if your film would be screwed up or not. They apparently had NO quality control, to catch and resolve problems.
Kodak was more expensive, but reliable.

 

[ADemuth]

ac12 - Color layers sounds familiar to me, and that all makes sense. As I go through more slides, I'll pay more attention to who processed it - maybe even peel it apart to see if I can find out what film was used. I've noticed that some slides are faded red, kind of like a b ad white balance while others seem to be monochrome red without a hint of any other color, and the monochromatic ones seem to be in large chunks - perhaps entire rolls. Not all of these slides are Kodak processed, just a great deal of them, perhaps that's some of the problem. This mystery may clear up soon.

tkbslc - For myself: definitely culling very heavily. I'm about 2000 into it and have only pulled a dozen or so slides I want to keep and clean up. I'm really digitizing these as a surprise for my grandmother. She loved slide shows and I'm trying to replicate that experience for her, so I'm not culling (much), nor am I re-organizing. I'm also not too worried about image quality - the condition that the slides are in are the condition that Gram used to view and would be still viewing if she could still set up the projector and screen by herself. They're actually getting quite a massage with AE and AWB.

 

[ac12]

I barely recall from way back then, but I think certain off brand films had reputation for bad color.
But that could be because Kodak would not process them, only Technicolor. So it could have been a processing issue.

I see you are in Palau.
Temp that the film was subject to and how long it was left before being developed may have a factor in what the color looks like.
I don't remember any of the details of what effect temp and time have on undeveloped latent images. That was too long ago.

 

[SandyO]

Interesting conversation as I'm well into the scanning of old slides going back to 1974. I've heard of all the color shift issues relating to this and was very glad that I have not actually run into that .....even with Kodachrome. Of the 2 images below the one of the car was taken in 1974 and of unknown film, probably Ektachrome of some sort, and the one of the cat taken in 1978 was definitely Kodachrome 64. Slides were scanned on an Epson V850 Pro with no color adjustment setting during scanning or post. Only setting during scanning was ICE. These slides were stored in the original plastic boxes and inside a cardboard box with no special care taken in storage. Sometimes they sat in an unheated garage for years on end. What causes the color shifting does seem to be a bit of a mystery. Bad processing is a definite possibility for some film types but the Kodachrome was being processing directly by Kodak. Even though mine were packaged well, particular care during long term storage was not really considered and I consider myself lucky on that part. One thing I though of was off gassing from different types of storage mediums such as plastic sleeves that may not have been the best choice archivally.

Subscribe to see EXIF info for this image (if available)

1974 Capri by soates50, on Flickr

Subscribe to see EXIF info for this image (if available)

1978 Cat by soates50, on Flickr

 

[Arundo Donax]

A while ago I scanned some of my father's old slides, and found the Ektachromes that were developed using the older E-4 process were faded and red-shifted to a much greater degree than those processed with the current (since 1977) E-6 system. Also, those that were processed by Kodak labs were in much better shape that the slides that were sent to a local, independent lab.
The Kodachrome slides looked like they could have been taken yesterday!

 

[Sammyboy]

.... aged GAF slide film is notorious for having a red cast, never had a problem with any of the Kodachrome slides ......

 

[Hendrik]

I have a few of my in-laws' Kodachromes from the late 40s and many more from the early 50s. They hold up very, very well.

 

[ralf-11]

IIRC, Kodachrome is archival

 

[ADemuth]

Heh - I *was* in Palau - Thanks for the reminder to change that.

I burned through 600 yesterday - Upon closer observation, there isn't a single "Processed by Kodak" Slide that exhibits the deep red monochrome. Same with Agfacolor slides. My Leica slides sample is too small to give any certainty, but they're great too. There are some in all brands with a slight red or yellow cast to them, but my IC AWB seems to neutralize those. The biggest offender are the no-name, unbranded slides, and the worst ones have red lettering that say something to the effect of "35mm Film Slide Transparency" - as if somebody was wondering what that cardboard square was with a clear image affixed to the hole in the center. Perhaps the developing company produced everything from shovels to wheelchairs for zebras and needed a concise label so their spatula riveters/film processors knew to put them in a mailer and not to make a cooking implement out of them.

 

[Brownie]

Heh - I *was* in Palau - Thanks for the reminder to change that.

I burned through 600 yesterday - Upon closer observation, there isn't a single "Processed by Kodak" Slide that exhibits the deep red monochrome. Same with Agfacolor slides. My Leica slides sample is too small to give any certainty, but they're great too. There are some in all brands with a slight red or yellow cast to them, but my IC AWB seems to neutralize those. The biggest offender are the no-name, unbranded slides, and the worst ones have red lettering that say something to the effect of "35mm Film Slide Transparency" - as if somebody was wondering what that cardboard square was with a clear image affixed to the hole in the center. Perhaps the developing company produced everything from shovels to wheelchairs for zebras and needed a concise label so their spatula riveters/film processors knew to put them in a mailer and not to make a cooking implement out of them.

Sounds like maybe York or one of the other mail-in processors of the day. You'd send in your film and get the photos back in about a week with a fresh roll of their film.