Straightening/flattening warped 35mm slides for scanning

[srosenow_98]

Hi, all (first post here, and hope to be a valued member!).

A while back, I came into possession of some rare, one-of-a-kind slides of the Mount St. Helens eruption on May 18, 1980. These slides were duplicates of some well-known photographs by three prominent eruption eyewitnesses (two of them a husband-and-wife pair of geologists in a Cessna C182 plane, directly over it when the eruption began).

One of the slides, taken less than two minutes into the start of the main eruption from a clearcut 8 miles northeast of the peak, had ink from a Sharpie somehow get transferred to the emulsion side of the slide transparency. A few nights ago, I'd used an alcohol prep pad soaked in 100% alcohol and managed to completely remove the Sharpie ink, but in the process, the slide transparency itself slightly warped when it dried. Unfortunately, as a result, only portions of the image come to focus in my Kodak Medalist AF slide projector, while the remaining portions of the image are slightly out of focus. 

An effort to try and fix the slide warp issue by applying heat didn't work as I'd hoped. It didn't make it worse (thankfully), but it didnt flatten the slide. 

On another pair of slides, both of which were taken directly over the summit as the eruption began by the aforementioned husband-and-wife pair of geologists, the slide transparencies have developed a slight curve within their mounts on one side, to cause about one third of the image (on the left side of the image, when projected) to come out of focus. I've refrained from using heat on these two, out of a fear it'll make things worse.

Besides glass slide mounts (which I've thought of buying), is there a way to fix these slides without changing them out of their existing mounts? I ask because the first slide mentioned, is part of a 14-slide set which came from the photographer that took them, and on the top of each slide mount is the label "MT ST HELENS ERUPTION - MAY 18, 1980 - (C)1980 KEITH RONNHOLM" and the other two slides have image captions in printed labels describing each slide. Affected Slide No. 1 is labeled "5.1 earthquake. May 18, 1980. 8:32 A.M... It begins. (C)1980 Keith Stoffel" and the other affected slide is labeled "Bulge and north face collapses down mountain. (C)1980 Keith Stoffel."

I'm reluctant to change them out of their mounts for the loss of the slide mounts themselves, and I'm wondering if there's a way to fix these without having to buy glass slide mounts.

MY SECOND QUESTION.

I've read that on glass slide mounts, the glass panes within said mounts have surfaces which prevent Newtonian rings from forming in the scanning/projection process. In reading about this feature, I've read that the way in which the panes are treated to eliminate Newtonian rings from forming, causes a slight grainy texture to appear on scanned/projected slides.

How bad is this "grain," and can it be overcome with image processing? My plan (although I've done it with my DSLR) is to scan these at a high resolution to digitize them.

[AJG]

I'm not aware of any way that you could flatten a slide while still in its mount, but I wouldn't worry about anti Newton's rings glass having any noticeable effect on a projected image.  When I shot 120 Kodachrome I glass mounted the "keepers" because the cardboard mounts could not keep the film flat enough for projection. As for your project, these images are still under copyright so anything other than personal use would require seeking permission from the photographer. 

[John Seaman]

You don't say how you plan to do the scans and with what scanner. You may find that the slightly warped slides come out OK even though they are out of focus when projected. The scanner may have more depth of field than the projector, which has a large aperture lens. My flatbed scanner has more depth of field than might be expected.

If you photograph them on a light box it may also be possible to get sufficient depth of field by using small apertures.

 

[srosenow_98]

35 minutes ago, John Seaman said:

You don't say how you plan to do the scans and with what scanner. You may find that the slightly warped slides come out OK even though they are out of focus when projected. The scanner may have more depth of field than the projector, which has a large aperture lens. My flatbed scanner has more depth of field than might be expected.

If you photograph them on a light box it may also be possible to get sufficient depth of field by using small apertures.

 

I've been eyeing some of those desktop scanners like the Digitnow kind (although I've looked at a few in the $400 range, but I cannot afford that right now). They'd be scanned at about 20megapixel range and then enhanced in TopazAI.

[Ed_Ingold]

You could jerry-rig a copy stand, using light box and a camera with a 1:1 macro lens. You could use the lens at f/8 without undue loss due to diffraction. Another possibility is to use that setup, stepping the distance or focus ring, using focus-stacking software, to get everything in focus.

[mikemorrellNL]

I've never used slides (warped or otherwise) but I do scan old photos and I do post-processing.

My 2 cts:

- if you really do want to preserve the slides in the original mounts then +1 for @John Seaman's and especially  @Ed_Ingold's suggestions. 

- Google is your friend: there are many articles related to slide scanning and printing

- One possible 'solution' (?) I've not read yet is to use the focus ring on your projector + a fixed digital camera to provide 'in focus' photos that can later be used for digital focus stacking

- There seem to be many 'service companies' that will produce 35mm slides from (stacked) digital photos; Google also offers DIY solutions.

[AlanKlein]

Remove the old slide holder and use one from another slide holder of a shot you're going to discard.  

[srosenow_98]

8 hours ago, AlanKlein said:

Remove the old slide holder and use one from another slide holder of a shot you're going to discard.  

Won't be discarding any of these slides. All 140+ are historically significant and document the 1980 eruption cycle of Mount St. Helens. 

[AlanKlein]

 

Don't you have an old slide from your own shots you don't really need, maybe a duplicate. 

[digitaldog]

35 minutes ago, AlanKlein said:

 

Don't you have an old slide from your own shots you don't really need, maybe a duplicate. 

Do attempt to read what the OP has stated in the first post! "I'm reluctant to change them out of their mounts for the loss of the slide mounts themselves"

To the OP: I'm with the other(s) suggesting you leave everything alone, try using a focus stack. Non invasive and likely to handle the focus issue, if there is one which may not be the case depending on the scanner or better, shooting the image with a DSLR with sufficient DOF. 

Edited December 26, 2022 by digitaldog

[conrad_hoffman]

I've recently been doing some company history and slides have been most valuable because they often have the processing date stamped onto the mount. Most of the prints I have are a mystery regarding date. I would not remount them and would just copy at a smaller aperture or focus stack. Don't create further mystery for somebody in the future. 

[AlanKlein]

11 hours ago, digitaldog said:

Do attempt to read what the OP has stated in the first post! "I'm reluctant to change them out of their mounts for the loss of the slide mounts themselves"

To the OP: I'm with the other(s) suggesting you leave everything alone, try using a focus stack. Non invasive and likely to handle the focus issue, if there is one which may not be the case depending on the scanner or better, shooting the image with a DSLR with sufficient DOF. 

So he has to use another type of slide mount if he has no spares.  Either from his own or buy a glass type or whatever.  It's an option.  If he doesn't like my option, he can do something else.   

[digitaldog]

20 minutes ago, AlanKlein said:

So he has to use another type of slide mount if he has no spares.  Either from his own or buy a glass type or whatever.  It's an option.  If he doesn't like my option, he can do something else.   

No he doesn't have to! It's an “option” he doesn't want nor must use. Read and then listen to his words Alan! 

"Listen to understand instead of listening to respond." - Barack Obama

Edited December 26, 2022 by digitaldog

[srosenow_98]

On 12/25/2022 at 5:42 PM, AlanKlein said:

 

Don't you have an old slide from your own shots you don't really need, maybe a duplicate. 

I'd like to add that I never alluded to having a set of spare mounts, nor alluded in any way of having taken my own photographs of the event - much less any slides of my own. I was only one week over six months old when Mount St. Helens erupted in 1980, and thus, too young to even hold a camera. However, I've been a researcher of Mount St. Helens (and an avid Mount St. Helens enthusiast and photographer myself, having named my own photography business after the volcano) for 35 plus years. These slides I recently acquired came in three separate purchases on eBay. The second two purchases were slide lots produced by Finley-Holiday Films Corporation, which distribute slide sets and a Mount St. Helens documentary in 1980 titled "Keeper of the Fire" (produced, filmed, and written by Seattle filmmaker Otto Sieber).

The first set I purchased was produced and sold by the photographer that took them, and came with a two-page shot record typed on a typewriter authored by said photographer (it even has his 1980 mailing address and telephone number on the contact header up top).

And in the case of the warped slide in question, it's a shot by the aforementioned photographer, none other than eruption eyewitness Keith Ronnholm (who shot an impressive sequence of photos of the first eight minutes of the eruption) and the top of the slide mount is labeled:

"MT ST HELENS ERUPTION
MAY 18, 1980
(C)1980 KEITH RONNHOLM" 

The labeling is done via permanent-ink dot-matrix printing slightly engraved into the slide mount, which itself is fundamentally undamaged. Attached is the slide set in question. Fourteen of the twenty slides are by Keith Ronnholm, three are from geologists Keith and Dorothy Stoffel (who were in a Cessna aircraft directly over the summit when the eruption began), three are from USGS geologist Austin Post (and as a result, are Public Domain) and one by NOAA (again, public domain).

The damaged slide is Slide No. 9. You can see the warping of the transparency, which is causing parts of the image to focus while the rest of the image is out of focus.

You can see why I'm wanting to preserve the original mount as much as possible, so as not to interrupt the collector value of this slide amongst its siblings.

 

Edited December 27, 2022 by srosenow_98

[digitaldog]

19 minutes ago, srosenow_98 said:

You can see why I'm wanting to preserve the original mount as much as possible, so as not to interrupt the collector value of this slide amongst its siblings.

Yes, some of us can understand that desire. Preserve that original mount. 

[kmac]

The old fashioned way was to copy the slides using a copying attachment fixed to a film camera. If the original slide mounts are plastic, which they look like to me, they will split in two and you can retrieve the slide/s and mount them into glass mounts for the copying. You would then get the positive copying film processed and then either swap the new slides for the old damaged ones, or just simply mount the new ones and use those for projecting.

If the original slide mounts are glued together and won't come apart, I would still use the film camera to copy the slides, closing the aperture opening right down and ensure no stray light reflected off the slides while copying. A 36 exposure film for copying would afford bracketing x ten for each problem side, allowing you to take your pick of the best copies.

[AlanKlein]

10 hours ago, srosenow_98 said:

I'd like to add that I never alluded to having a set of spare mounts, nor alluded in any way of having taken my own photographs of the event - much less any slides of my own. I was only one week over six months old when Mount St. Helens erupted in 1980, and thus, too young to even hold a camera. However, I've been a researcher of Mount St. Helens (and an avid Mount St. Helens enthusiast and photographer myself, having named my own photography business after the volcano) for 35 plus years. These slides I recently acquired came in three separate purchases on eBay. The second two purchases were slide lots produced by Finley-Holiday Films Corporation, which distribute slide sets and a Mount St. Helens documentary in 1980 titled "Keeper of the Fire" (produced, filmed, and written by Seattle filmmaker Otto Sieber).

The first set I purchased was produced and sold by the photographer that took them, and came with a two-page shot record typed on a typewriter authored by said photographer (it even has his 1980 mailing address and telephone number on the contact header up top).

And in the case of the warped slide in question, it's a shot by the aforementioned photographer, none other than eruption eyewitness Keith Ronnholm (who shot an impressive sequence of photos of the first eight minutes of the eruption) and the top of the slide mount is labeled:

"MT ST HELENS ERUPTION
MAY 18, 1980
(C)1980 KEITH RONNHOLM" 

The labeling is done via permanent-ink dot-matrix printing slightly engraved into the slide mount, which itself is fundamentally undamaged. Attached is the slide set in question. Fourteen of the twenty slides are by Keith Ronnholm, three are from geologists Keith and Dorothy Stoffel (who were in a Cessna aircraft directly over the summit when the eruption began), three are from USGS geologist Austin Post (and as a result, are Public Domain) and one by NOAA (again, public domain).

The damaged slide is Slide No. 9. You can see the warping of the transparency, which is causing parts of the image to focus while the rest of the image is out of focus.

You can see why I'm wanting to preserve the original mount as much as possible, so as not to interrupt the collector value of this slide amongst its siblings....

...

Being a lot older than you, I remember the explosion quite well.  Having rare slides of the event is a wonderful collector's item. I'm curious.  How does copyright work with these if you want to sell them or replicates for publication or other uses?  

[digitaldog]

45 minutes ago, AlanKlein said:

How does copyright work with these if you want to sell them or replicates for publication or other uses?  

Again, Google can be your friend if you try, then read, and listen:

https://www.asmp.org/wp-content/uploads/PhotographersGuidetoCopyright.pdf

https://www.ppa.com/understanding-photographic-copyright

https://www.copyright.gov/engage/photographers/

 

Edited December 27, 2022 by digitaldog

[srosenow_98]

1 hour ago, AlanKlein said:

Being a lot older than you, I remember the explosion quite well.  Having rare slides of the event is a wonderful collector's item. I'm curious.  How does copyright work with these if you want to sell them or replicates for publication or other uses?  

I'm not sure what your intent behind your responses are, but IMO they're kind of coming off snarky. And they really haven't been helpful.

For one, I'm a photographer. In fact, published globally both online, print, and broadcast. I've signed multiple usage rights agreements with multiple publishers and media agencies.

To that end, I know copyright law (the entirety of Title 17, United States Code, in fact) quite well. In fact so well that as a day job for five years, I worked in a photo print lab in which I was bound by company policy, to hold copyright acknowledgment agreement forms on file for a period of five years. 

Respecting copyright is one of my most basic tenets of being a photographer itself.

With that in mind, I have no plans on selling these slides much less any plans of selling any reproductions of them, so long as I don't have prior permission from the photographers who took them, beforehand. But, in that, it's kind of pointless to insinuate I plan on selling them, seeing as how I bought the set in question from a private seller on eBay located halfway across the country, who presumably either purchased them via an estate sale, antique shop (or some other means), or maybe even perhaps bought them from Keith Ronnholm himself (seeing as how it came with his original paperwork from 1980, including a two-page shot record typed on typewriter complete with his 1980 PO box address and telephone number, as part of the eBay listing).

In addition, as Mount St. Helens' 1980 eruption was the most violent and most destructive volcanic event in the entire history of the United States in terms of land destroyed, economic impact, and the sheer power of the eruption itself (and by far the deadliest), I do have a plan to work with the photographers that took the originals to publish a never-before-attempted look into the first ten minutes of the eruption. 

The reason? Over twenty five photographers documented the beginning of Mount St. Helens' 1980 explosion, and combined produced over two hundred individual photographs. Five of them produced sequences which were instrumental in recreating the entire event in the scientific reconstruction of the eruption and how it unfolded. 

Of the more than 40 major publications and over 1,000 in all on that event, none have published the entirety of that event, and as some of those photographers were in their 30s and 40s when the event happened (and are close to the end of their lifespans), it makes sense to try and get these photos preserved and published, so that future generations can see the impact of that event, and so that it may foster an interest in geology or volcanology (after all, my interest in the event was spawned by the Gary Rosenquist sequence, Keith Ronnholm's sequence, and KOMO Photographer Dave Crockett's video, the latter of whom I've met in person).

And just so we're also clear here, United States Copyright law also has a Fair Use Doctrine, which provides limited usage of copyrighted materials without having to seek the permission from the copyright holder in question. This is most often limited to the spectrum of research, providing public commentary, news dissemination and the like.

-Steve

Edited December 27, 2022 by srosenow_98

[digitaldog]

Steve, you are new here. Me (and Alan) not so much so let me 'defend' Alan 🤑 and explain, he's not being Snarky. That is way, way above his pay grade! There is a history here and over on the LuLa forums of this kind of agenda. Alan has difficulty reading and comprehending posts, has ideas that are funny and absurdly wrong (a major one being "All original prints are 300 DPI"). There's many more sadly. He's someone who never lets complete ignorance of a subject get in the way of having strong opinions about it. Just ignore him. 

Edited December 27, 2022 by digitaldog

[srosenow_98]

12 minutes ago, digitaldog said:

Steve, you are new here. Me (and Alan) not so much so let me 'defend' Alan 🤑 and explain, he's not being Snarky. That is way, way above his pay grade! There is a history here and over on the LuLa forums of this kind of agenda. Alan has difficulty reading and comprehending posts, has ideas that are funny and absurdly wrong (a major one being "All original prints are 300 DPI"). There's many more sadly. He's someone who never lets complete ignorance of a subject get in the way of having strong opinions about it. Just ignore him. 

Points all well taken!

[Rick Helmke]

I’m not taking the time to read through all of this so I’ll just say that I recently completed a scanning job of about 800 slides going back to the early 50’s. I doubt they were stored all that carefully and all are in some sort of paper mount. There were no focus problems involving the scan process but the photographer let a few get away.  Buy, rent or borrow a Nikon Coolscan and go to work. If the slides aren’t perfectly flat you should be fine. 
 

Rick H.

[AlanKlein]

11 hours ago, srosenow_98 said:

I'm not sure what your intent behind your responses are, but IMO they're kind of coming off snarky. And they really haven't been helpful.

For one, I'm a photographer. In fact, published globally both online, print, and broadcast. I've signed multiple usage rights agreements with multiple publishers and media agencies.

To that end, I know copyright law (the entirety of Title 17, United States Code, in fact) quite well. In fact so well that as a day job for five years, I worked in a photo print lab in which I was bound by company policy, to hold copyright acknowledgment agreement forms on file for a period of five years. 

Respecting copyright is one of my most basic tenets of being a photographer itself.

With that in mind, I have no plans on selling these slides much less any plans of selling any reproductions of them, so long as I don't have prior permission from the photographers who took them, beforehand. But, in that, it's kind of pointless to insinuate I plan on selling them, seeing as how I bought the set in question from a private seller on eBay located halfway across the country, who presumably either purchased them via an estate sale, antique shop (or some other means), or maybe even perhaps bought them from Keith Ronnholm himself (seeing as how it came with his original paperwork from 1980, including a two-page shot record typed on typewriter complete with his 1980 PO box address and telephone number, as part of the eBay listing).

In addition, as Mount St. Helens' 1980 eruption was the most violent and most destructive volcanic event in the entire history of the United States in terms of land destroyed, economic impact, and the sheer power of the eruption itself (and by far the deadliest), I do have a plan to work with the photographers that took the originals to publish a never-before-attempted look into the first ten minutes of the eruption. 

The reason? Over twenty five photographers documented the beginning of Mount St. Helens' 1980 explosion, and combined produced over two hundred individual photographs. Five of them produced sequences which were instrumental in recreating the entire event in the scientific reconstruction of the eruption and how it unfolded. 

Of the more than 40 major publications and over 1,000 in all on that event, none have published the entirety of that event, and as some of those photographers were in their 30s and 40s when the event happened (and are close to the end of their lifespans), it makes sense to try and get these photos preserved and published, so that future generations can see the impact of that event, and so that it may foster an interest in geology or volcanology (after all, my interest in the event was spawned by the Gary Rosenquist sequence, Keith Ronnholm's sequence, and KOMO Photographer Dave Crockett's video, the latter of whom I've met in person).

And just so we're also clear here, United States Copyright law also has a Fair Use Doctrine, which provides limited usage of copyrighted materials without having to seek the permission from the copyright holder in question. This is most often limited to the spectrum of research, providing public commentary, news dissemination and the like.

-Steve

I'm sorry you're taking my question so negatively. Sometimes things get misunderstood in a forum.  It's a natural question to wonder what will happen to a valuable, original set of photographs considering current US copyright laws.  Until this post, you didn't go into great detail what you intended to do.  You seem to have a great interest in preserving them and I appreciate that and your explanations of how you intend to handle it.  Good luck and I hope you work out the problem with the slide. 

Edited December 28, 2022 by AlanKlein

[digitaldog]

19 minutes ago, AlanKlein said:

Sometimes things get misunderstood in a forum.  

By some here, often, yes! 🤔

20 minutes ago, AlanKlein said:

Good luck and I hope you work out the problem with the slide. 

He doesn't need luck. He only needs to listen to the on topic suggestions given by those with experience on the topic of scanning transparencies; by those reading his needs in doing so.

[digitaldog]

Ah, I loved this baby and what a price:

https://www.ebay.com/itm/352626898684

Now find an old Mac with SCSI and scan away. Slow (like 30 minutes start to finish) but superb quality only a PMT drum scanner could beat (and gotta unmount). 

Look at the lens on this beauty.