In the 1950s did processing labs number slides in the order they were taken?

[oldkodachrome]

Folks,
I'm in the process of scanning hundreds of old 1950s and 1960s Kodachrome slides from my family's photo collection. An issue has arisen as to when some of the transparencies were photographed by the person holding the 35mm SLR camera. On the top left corner of the cardboard slide holder (when the slide image is held upside down, which is how you insert it into the slide projector), there is a little red number printed on there by the processing lab. I have a series of slides labeled from number 30 to number 37. My deceased father wrote "October" in ink pen across the top of slides #30 to #35, but then he wrote "November" on #36 and then "October" again on #37 probably by mistake. This begs the question: If the roll of film was exposed and processed in sequence, then how could you take a bunch of photos in October and then one in November, and then go back in time to snap another in October again?!

So here are my questions (Note: I have absolutely no knowledge of photography other than how to use my cheap Cannon PowerShot to snap photos for eBay sales.):

1. Was it common practice for photo processing labs in the 1950s to mount your slides and number them in the order you took the pictures?

2. Could a lab have processed & mounted & numbered the slides in the reverse order you took them? Or did they mount & number them randomly?

3. How many exposures were in a roll of Kodachrome transparency film in the late 1950s and up to the mid-1960s?

And a related question:
4. I have noticed some kind of coating on the emulsion side of the Kodachrome slides. When a desk lamp is reflected off of it, you can see horizontal bands of rainbow colors. This appears only on the slides from around 1955 to 1960. It doesn't seem to affect the scanned image on the slides that are undamaged, but many slides have spots of mold on the emulsion (due to storage in the basement). How can I clean them? How can I remove finger prints off the emulsion side?

Thanks a bunch!
John

 

[Dwig]

...
1. Was it common practice for photo processing labs in the 1950s to mount your slides and number them in the order you took the pictures?

No, they were numbered in the order that they were mounted. This would be in the order they are on the film from leader to cassette. Unless there was some odd happenstance, this would normally be the order that they were taken.

2. Could a lab have processed & mounted & numbered the slides in the reverse order you took them? Or did they mount & number them randomly?

They numbered in order, but accidents do happen. A fault in the mounter could cause a frame to be pulled, unmounted, and then hand remounted leaving it unnumbered. Faults during exposure that resulted in unevenly spaced images (pressing the rewind button mid-roll would do this on most cameras) would cause an interruption in the mounting. The rest of the roll would normally pick up the numbering just after the last image before the fault, but the numbering could accidentally have been reset leaving duplicate numbers on the same roll.

3. How many exposures were in a roll of Kodachrome transparency film in the late 1950s and up to the mid-1960s?

Two lengths were available then, 20 exposure and 36 exposure. I believe there were shorter rolls available in the very early days, late '30s.

And a related question:
4. I have noticed some kind of coating on the emulsion side of the Kodachrome slides. When a desk lamp is reflected off of it, you can see horizontal bands of rainbow colors. This appears only on the slides from around 1955 to 1960. It doesn't seem to affect the scanned image on the slides that are undamaged, but many slides have spots of mold on the emulsion (due to storage in the basement). How can I clean them? How can I remove finger prints off the emulsion side?...

For a long time, Kodachromes were coated with a clear lacquer in the lab. This is probably what you are seeing. Personally, I leave this alone when scanning my antique slides and just spend more time in Photoshop retouching.

The lacquer can be removed, but there is risk of damaging the original. Before attempting to clean the film make the best scan you can to serve as a backup if you damage the slide in the cleaning attempt.

My old notes have two formulas for removing lacquer. The simplest is:
-1 tbsp of Sodium Bicarbonate diluted in 16oz of cool water
-Agitate film for one minute at 60-70 degrees F
-Rinse quickly and treat in normal Kodak Photo-Flo (standard dilution) for 30 seconds.
-Hang to dry

The other is:
-1/2oz ammonia mixed with 8oz of denatured alcohol
-Agitate film in solutio for 2 minutes, not any longer
-hang film to dry.

I've never used either; use at your own risk. I don't risk damaging the originals.

 

[KmH]

I had to check to be sure I was in the Beginners forum.

 

[Plato]

They were numbered based on how they came out of the cassette. Most cameras started from the leader and it was necessary to rewind the film back into the cassette before removing the cassette. If you forgot, the roll was ruined and if you accidentally opened the camera, all exposed frames were ruined. For that reason, some cameras (Fuji comes to mind) worked the opposite way. The film was wound out before you took shots and, as you took each shot, it was wound into the cassette. This ensured that accidentally opening the camera would ruin only the most recent one or two shots.

Frequently, the first frame was not a valid photo and was discarded so the numbering would start with #2. Of course, with the reverse loading Fuji, this was moot.

In the fifties and sixties, 20-shot rolls were the norm and large rolls were 36-shot. Later, the standard sizes were 12, 24 and 36. Rolls larger than 36 were not commonly available but some photographers loaded their own rolls and were able to squeeze in more shots. This is true for Kodachrome as well as other films except that I don't think that you could load your own Kodachrome.

 

[oldkodachrome]

Thanks folks!
The information you have given is VERY helpful. It appears my father used a lot of the 36-exposure rolls, because the highest numbered slide I have seen so far is 37 and I have many sets with the last slide numbered 35 or 36.

I don't think I will attempt to clean any slides, but I do wonder if any photo supply company sells a bottle of cleaning fluid, something that is safe & easy to use.

Kind Regards,
John

 

[Dwig]

...I do wonder if any photo supply company sells a bottle of cleaning fluid, something that is safe & easy to use...

Edwal Anti-Stat Film Cleaner is a reliable product:

Amazon.com: Edwal Anti-Stat Film Cleaner, for Black & White and Color Films, 4 Oz. Bottle: Camera & Photo

You would need to unmount slides before cleaning. Otherwise you just push the grime into the corners. You would probably want to remount afterwards. There are a number of mounts availble, but these are easy to use by hand and inexpensive:

Amazon.com: Pakon 2x2 35mm Standard Pastic Slide Mounts 1.3mm Thick (24 x 36), Glassless, Pack of 100: Camera & Photo

 

[c.cloudwalker]

I never bothered to load my own film cassettes and have 37 exposures on most of my films (38 exposures more rarely) and all it is, is how you load the film in the camera. With the newer type of camera described by Plato, I doubt this is possible as the loading is automatic and the camera rewinds when you hit the last official frame.

I have washed old negatives with no problems whatsoever. However, those were B&W so I wouldn't want to give you chemical names as they may be different. If you really want to do this, I would suggest going to a forum dedicated to film where you probably would find better info.

But, as Dwig said, before you attempt any cleaning, make sure you have a great scan of that particular slide first. Then, try it out with the least interesting slide as there is a serious possibility of damaging the film when you try and get it out of the cardboard frame.

Then, if you find out that you can do both without damage, do only one complete film at a time. Frame numbers should be on the film itself and when you put them back in new frames number them as you go.

Your choice of frames today will, I imagine, be either plastic slide-in or glass snap-together type. There is no risk of scratching the slides with the glass type but they are more expensive and they are not considered archival by a lot of people. If you use the slide-in type, be careful with scratching.

Best of luck with this project.