tomspielman

A poorly skipped stone.

Sure, it's all about chemistry and physics if you insist on breaking it down to that extent. But the same is true of a painting. The image on the canvas is a rendering of what was in the artist's brain. The image may have evolved as they were painting it. It may turn out quite different from what they "imagined", but the painting didn't spring from nothing. It's neurons firing, and chemical processes occurring, - physics and chemistry. From the time the first hint of it entered their brain until the last brush stroke. Physics and chemistry. And unless you have all the knowledge to work backwards from the final image to understand exactly how the photons were manipulated to produce it, a photograph isn't trustworthy. An individual photograph might be a faithful rendering of what someone's eyes and brains would see. But it might not. It might not even be close. It's still a poor description whether it was you, some playwright, or a plumber that came up with it. My bokeh balls as you call them are a perfect example. What exactly is being indexed? A few years ago I would have had no idea how to produce image like that. It does not look like anything in the world that I've seen in real life. The camera produced an image from the photons, but not in any way close to how your eyeball would. It's a construction. it's even a bit random though I'm sure it all can be explained through physics. The photographer may have tried 20 times to get an image they wanted by changing angles, exposure, etc. 20 different images of the exact same physical things. Remove the heart shaped aperture, add some light, close the aperture and the image produced is entirely different. All these images are indexes of the world? Only in a very useless sense. You're placing a constraint on photography that's an artificial one. It may be a necessary constraint for a journalist, but not necessarily for a photographer with more artistic goals.

Photos can be trustworthy or not. They can look real or not. A somewhat cheesy example from diyphotography.net, - the bokehnator "index the world" is an odd way to describe photography and there are plenty of cases where the phrase is inadequate if not completely inaccurate. And again, you choose to ignore that part of photography that happens after the shutter button is pressed, either in the darkroom or on a computer.

No of course not. But one can use the way cameras work to serve a particular purpose. One purpose might be to create an illusion, - just like real flesh and blood people (or "facts" by your interesting definition) can portray works of fiction. If I open the aperture on the camera, do distant trees really get blurry? No. Further, their leaves don't really turn white if I'm using infrared film and a red filter. The film and the camera are deliberately emphasizing certain photons while practically ignoring others. What is happening to the facts? These are just simple examples. You can take a photograph of Miss Wilkins (Juliet) looking longing at Mr Jones (Romeo) and the viewer might think that Juliet or Miss Wilkens is in love with Mr. Jones or Romeo, but in reality she might hate both of them.

It happens because sometimes photographs are taken for that purpose (evidence). But that does not represent the whole of photography. Written documents are also used as evidence but that doesn't mean one can't write great works of fiction. And sometimes the best works of fiction can be mistaken for fact. I'm thinking of the "Onion".

He's wrong. ;) I understand completely what you're saying about a painting. But you can certainly photograph a model, - or an actress playing Juliet, helpfully put a caption underneath the framed photo, - and she will be Juliet to the viewer. Just as someone watching an actress on stage can see her as Juliet while still knowing that she's actually an actress. GBS is incorrect. You can manipulate photons. That's what lenses do. In fact, a huge part of photography depends not on truth but fantasy. Often times the goal of photography is depicting things and people (or food) not as they are, but as how we want them to be seen. And plenty of times, the viewer is in on it, - though not always.

I know this discussion is weeks old but there is something about it in particular that would pop into my brain now and then and that's the discussion of Juliet. I'm assuming Leo is referring to Juliet of "Romeo and Juliet". To be sure there are many paintings of Juliet. But she was a character written for the stage, - intended to be played by a flesh and blood actress in costume. The idea that a painting could properly capture Juliet while a photograph could not doesn't make any sense given that Juliet was meant to be portrayed by a real person. Yes, a camera can capture what is real, but it can also be a tool for the imagination. Just as flesh and blood actors and actresses can bring works of fiction to life.

A friend of mine's father was a college professor who taught photograph, among other things. His family kept a lot of his equipment and supplies for a few years after he died but eventually decided to sell or donate what they thought had some value and give away, or throw away the rest. I ended up with a box of film of all kinds. It was stored properly but some of it is pretty old, - going back to the 90's. Included were two boxes of Ektachrome, - one of which I shot. The other is a 50 ASA tungsten balanced roll. I usually expose old film longer anyway but that one would need a filter on top of being already on the slow side. I like to use fresh chemistry with fresh film and since new slide film is pretty expensive I haven't bought any yet. So my exposed roll sits in the fridge. I'm interested in E6 but so far I haven't been interested enough. :) Christmas is coming up so maybe I'll ask for some Velvia and an E6 kit. Some people like tungsten balanced film without a filter for Winter shots. It's worth a shot.

Yes, with bitcoin you're not dependent on a single trusted location. Instead you're placing your trust in the fact that a given ledger (or block chain) agrees with multiple ledgers stored in multiple locations. Either way, the validation is external.

They do use digital cameras in manual mode for my daughter's photography class. She gets a little frustrated because the cameras are older and she gets better pictures on her phone without having to worry about shutter speed or aperture. ;) What digital can help you with is when meters get fooled. Backlighting is one example. You'll know right away and have to compensate... or just move. They also spend a lot of time on post processing in her photography class. So sometimes even backlight images that look bad straight from the camera can be fixed. As far as film goes, I've been very surprised at what can occasionally be coaxed out of negative that's on the thin side.

Sure, and that would all work. But it depends on comparing a hash to another hash stored at a trusted location. This doesn't meat the OP's criteria of having a file that's self validating.

A key component of a crypto-currency like bitcoin is the distributed nature of it. The history of transactions is verified by comparing to numerous other copies of that history. So you don't get away from having some sort of external/independent validation. An image from a camera that's stored in a block-chain format could store all the edits within the block-chain itself. You'd know that it wouldn't have been tampered with and could always get the original. But this is of no use unless the block chain is distributed so there would be something to verify against. Otherwise, one could merely put an altered version of an image in a separate block chain.

There's a line between wondering what happened to someone / hoping they're doing OK and stalking them. ;) I wish I had been around here when he was active. I've been active on forums and eventually moved on without any announcement. It wasn't ever anything intentional either, - just stopped over time. I also used to maintain a website but it's long gone. It had a very specific audience and after awhile it became more of chore than something I got pleasure from. I let it fade rather than shut it down or announce that I wasn't maintaining it anymore. My point is that Gene may be just fine and on to other things.

I've had this happen more than once though usually I realize it before I get to what would have been the end of the roll. So I've learned to double check that the rewind crank is turning when I advance the film. This did lead to another problem with a Nikon Nikonos. The rewind crank does not turn when you advance the film on that camera. And the film advance is really smooth, - to the point where I once convinced myself that I had not loaded the film properly... and opened the camera. Oops.

Wind turbine blade being transported via train

This is B&W film where the film itself has a bluish tint but otherwise the negative is clear after developing?

Glad you found the problem and thanks for posting the pics. I've had a couple of 35RCs and both meters worked but I've had to make similar repairs on two OM-1n cameras. One of those needed the whole wire replaced because it was so badly corroded. Lots of disassembly involved in that one. I don't have a 35RC now but they're a nice enough camera that I could see picking up another one in the future. It's always nice to know when problems with these cameras are fixable. Do you own a 3D printer or just have access to one?

I went through much the same thing a few years ago though I've never had my own darkroom. The first roll I had processed was through a local Walgreens. At the time there were still a few locally that processed film in the store. I had to wait until the one person who knew how to operate the machine came into work so it took a few days. The results weren't that good as I've mentioned. I did get the negatives back however. There is also a lab not far away that has pretty decent rates on processing only if you don't need prints or scans. It was still more than I wanted to spend though so I invested in a changing bag, found a tank and reel on craigslist along with an Epson V500. That got me started. The V500 has a scratch in the glass in a spot that meant I could only scan four 35 mm frames at a shot. Eventually I got really lucky and found a Nikon scanner for $100 than needed only minor repairs. The Nikon software won't work on modern macs but I prefer it to VueScan so I keep an old mac around just for using the scanner. From what I've read the Canon 8800f was pretty good. You can always send the negatives out for higher end scans if you had something you wanted to make a good sized print out of.

Not my area of expertise but I don't think it's practical and maybe not possible to have a file authenticate/validate itself using only itself as the source of truth since anything in the file can be modified. If you think about it, any sort of verification that's done now, - say verifying that the web site you're visiting is who they claim to be, depends on checking with an independent trusted source. So what would have to be stored in a trusted location is either a checksum or hash generated from the original image data or a copy of some subset of the original image data that was determined to be sufficient to identify another image as essentially the same. Where would this location be? How would the information get there? How could we know the image wasn't already altered before this data was sent?

I agree. Outside of journalism and when photographs are used as evidence, I don't know how important it is to know the degree to which a photo has been modified. FWIW, iPhones stores photos in HEIC format rather than RAW or jpeg. I don't seem them moving to something like jpeg 2000.

Well for me photography is just a hobby. I like fixing and using old cameras. I have no website. Is there something in particular wrong with Karim's post that make's it not suitable for Casual Photo Conversations?

I think you lose about 2 stops with a 2 X teleconverter so it may not have been faster than your 135 in the end. Photos also tend to be less sharp with teleconverters. Did Walgreens give you the negatives back and if so, how did they look?

I also tend to avoid 400 as well unless I'm shooting B&W indoors. I got the ultramax to use in an underwater camera where light is a challenge. I got 4 rolls in the box so most of the photos were taken above the surface but I did get a couple under water. I noticed that a lot of disposable film cameras use high speed film just so they'll work in a variety of situations. They are as popular as ever at weddings I guess though I can't imagine you get too many worthwhile pictures. My teenaged daughter and her friends like them as well for some reason. I salvaged a roll of 800 film out of a fuji disposable camera. Haven't been able to bring myself to use it.