cross-posted from: https://slrpnk.net/post/20333855
I am very pleased to introduce you a new photography community dedicated to vintage camera lenses.
The idea is to have a place to showcase our pictures made with vintage lenses, either from digital or analog cameras. Additionally, we welcome technical discussions about the use of this kind of lenses.
cross-posted from: https://feddit.org/post/10087158
I started as a pure JPEG-photographer, but Darktable sparked my interest in RAW-photography. Darktable has its quirks, especially for a complete beginner, but its manual way of doing things forced me to learn some fundamentals, instead of just sliding some sliders to see if something sticks.
What is your workflow in Darktable? Which module is a game changer for you?
These are the steps I almost always take:
- denoise (profiled): Match with the ISO of the photo, sometimes reduce 'preserve shadow'
- Lens correction: correction method: Lensfun database. It finds my camera and lens and I like the correction most of the time.
- exposure: turn up the exposure until my subject is well lit.
- crop: to compensate my ability to hold the camera horizontal
- color calibration: I often use the eye dropper on a neutral color, or on the whole picture. Then correct the hue and chroma a bit, until my picture is as balanced as possible.
- diffuse or sharpen: Preset 'lens deblur: medium' to get it sharper
- diffuse or sharpen (second instance): Preset 'local contrast'; I often turn up the iterations, I like it contrasty.
- color calibration: Preset 'basic colorfulness: standard' to get the picture more colorful. I often add even more saturation. What are those chroma-sliders for?
- filmic rgb: I use the eye droper for the white relative exposure. For the black relative exposure, I take a look at the darker parts and turn it down, until I can see enough details in the shadows.
I experimented a bit with the red/green/blue-channel in the color calibration module, according to Boris Hajdukovic. That was fun, but the modules 'color equalizer' and 'rgb primaries' are a bit easier to use to tweak the colors. The 'tone equalizer' is also often used to brighten up the darker parts of my pictures.
I've had the CMC bottled for a month now. I can see tiny mold spots growing on it now, but I can still use it. I initially mixed in 0.25% Sodium Benzoate as a preservative. I say as a preservative because that is what every food stuff that uses Sodium Benzoate says. I have very little clue about what it might be doing but I will keep this post updated as the time passes to see how long it lasts. I've used only maybe a 5th of the total 600ml or so that I made at 2% ratio to water. In this sodium benzoate ratio I haven't seen it form the precipitate when mixed with an acid yet, so there is a quantity as which that happens. Also I think its reversible because I can dissolve the precipitate with a good microwaving and mixing.
I guess I spoke too soon. The CMC formula is great though. The resolution is basically photographic.
https://lemmy.world/post/26591859
For use on plastics you need the sizing that I proposed on there. For regular paper I just noticed that that you shouldn't use peroxide to develop anything. First of all there's actually no hardening due to free radicals necessary. But I noticed that with bad paper, it will immediately turn all blobs of ugly gloppy blue. All that is needed is to remove the yellow sensitizer, so start with water only. But I am thinking that a better developer would be a quick wash in dilute HCl, citric, acetic, oxalic or sulfamic acid.
This is great cheap watercolor paper: https://a.co/d/aNkZqji It works fantastically out of the bag. It comes in a very losely packed thin plastic. Some complain that it comes damaged on the corners but that was not the case for me.
I've tried an old batch of nenah 94lb paper? And that worked well with less surface waviness. Photo paper blued badly on peroxide but maybe it will work with dilute acid.
cross-posted from: https://jlai.lu/post/17046774
Vue complète de la carte. Monochrome. On dirait presque un cyanotype !
D'autres vues ici.
Per this link: https://www.sciencedirect.com/science/article/abs/pii/S0141813020343622
"Due to its excellent film-forming ability, non-toxicity, biodegradability, and low cost, CMC has aroused great interest as an edible and biodegradable film material for food packaging [11,12]. Numerous studies have been shown that CMC film exhibited good transparency and effective oxygen, carbon dioxide barrier properties [12]. However, CMC film has rather inferior mechanical and water vapor barrier properties, which restricts its potential application in the food packaging field ".
I think a lot of these properties are great for alternative photography.
**Excellent film forming.
**Low cost.
**Oxygen inhibition.
**Water permeable.
This video is very cool to watch. I love that his work room is messy like mine.
https://www.youtube.com/watch?v=5kqr77X4IF8
I've tried Carbon not using dichromate and I've had very few successes so far. Using ferric ammonium citrate and oxalate, it has been such an elusive beast. But in the way there I've pit together my own cyanotype on anything formula and of course figured out how to use a dlp projector to expose images. All my negatives are basically just files.
I have dichromate but I'm afraid of using it. I work with aluminum components that get plated in various ways and a guy who used to work in the processing using dichromate died of cancer recently. Hexavalant chrome in conversion coatings is practically the same as dichromate. It seems harmless because its diluted but its definitely not. If I try it I'm gonna be using gloves and PPE.
I've been playing around with the DLP projector setup with its 1080p resolution. I measured the smallest features I've printed to be around 0.25 mm. Its small but not that small. I wonder what else could be done to get better resolution. Probably adding an aperture.
Not only did I make a cool print that I liked today but I developed a recipe to put Cyanotype on virtually anything. I'm a well accomplished individual. When I say developed I mean, I kind of think I'm currently the only one doing it exactly like this. I'm a lazy horse stemming from being an engineer so my method, I promise you, is for lazy leisurely alternative photography. I promise at Least you might make a print or two. OK Ego our of the way, let's share some stuff. This will be recipe AMO20250309
1)Apply this size to the surface:
1g gelatin,
1g gum arabic.
0.2g Sulfamic acid.
microwave for liek 9 seconds just to warm it up. Let it cool down before applying it...or not, you do you.
2)Following the Habib Saidane mixture ratios:
*1g 2% CMC (very thick substance).
*1ml water (or more to thin it down).
*0.25g sulfamic acid.
*1 dropper of mike wares New Cyanotype formula…a few drops Basically. More=darker darks.
Put this in the microwave for 12 to 15 seconds until it boils. If you do not do this, you'll never get it to mix, at least not that day. Let this cool down for sure or you'll ruin the bottom layer. Apply this only after the previous layer is dry.
I applied both using an air brush and the results are astounding. You can also achieve this by pouring both cold like a carbon tissue.
In my setup I exposed for 15 minutes but its probably more like 3 minutes in a UV lamp setup. To develop this, spray hydrogen peroxide 0.3% (not 3%). Wait 30 seconds. Then 1 wash in dilute acid for a few seconds. Sulfamic and HCL may make the blues brighter. Finally wash the yellow out in tap water in a few washes. This recipe doesn't frill and all the process happens in cold water, or warm water, you do you, the stuff is hard to dissolve unlike all the other recipes I've tried so far. Don't go too hot or it will start to dissolve the image. Don't wash too many times or it will start dissolving.
The original looks like this:
I'll just copy paste Habib's post: 1
Mar 7, 2025 #cyanotype #CHIBA #dichromate #cyanotype #CHIBA #dichromate Part 2 of a new process, inspired by CHIBA, that doesn't use animal products nor acids. It requires Ferric Ammonium citrate and two polymers: Gum Arabic and a cellulose derivative namely Methylcellulose or Carboxymethylcellulose (CMC).
Formula for a 100ml sensitizer solution:
10gr Gum Arabic (powder)
5gr Ferric Ammonium Citrate (powder)
1gr CMC or 1gr Methylcellulose (powder)
100ml of distilled water.
Directions: a) Expose in warm temperature environment 20°C or better b) Develop in 0.3% Hydrogen Peroxide at around 35°C c) Rinse in warm water at around 35°C
To participate help the research: https://paypal.me/AltResearch
Feel free to ask questions. You are welcome to join us on Facebook for more discussions: www.facebook.com/groups/alternative2
Have a great week and see you in the next video.
I will be making ferric chloride in a jar...+100g of Iron (acquired from fine steel wool) +100ml Water +100ml Muriatic Acid (~32%) =~200ml of Ferrous Chloride +200ml of 3% Hydrogen Peroxide =~400ml of Ferric Chloride
Why? Well it's a compound that will harden gelatin when exposed to UV. More interestingly, you need an inhibitor to prevent premature hardening. So the inhibitor happens to be either Ferric ammonium citrate or oxalate, which I already have on hand.
Alternatives to Ferric ammonium citrate and Oxalate, when it comes to photo linking CMC are photoinitiators:
Irgacure 2959
Lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP)
2,2'-Azobis[2-methyl-N-(2-hydroxyethyl)propionamide] (VA086)
All 3 things are really expensive though. But you only need a tiny amount.
Today I've sort of discovered that you can definitely use CMC almost by itself to make cyanotypes.
Here's the formula. Let's call it the AMO20250303 formula, which is all I ask that you do for me for teaching you this formula. Mention it by this name in other forums and try it out!
Following the Habib Saidane mixture ratios:
*1g CMC (very thick substance).
*1ml water (or more to thin it down).
*0.3g zodium benzoate (may not play a role).
*0.25g sulfamic acid (adding this will make it a thick white foam immediately after adding it).
*1 dropper of mike wares New Cyanotype formula...a few drops Basically.
exposure:10sec under a strong uv LED COB, or 15 minutes under a projector. Spray 0.3% peroxide. The peroxide starts the Fenton reaction to polymerize and also instantly oxidizes the cyanotype. Then just wash it in increasingly warmer water until all extra blue and yellow has cleared.
The attached photo gives you an idea of the resolution achievable. I expose using a 3000L DLP projector at 1080P so the image's resolution is not too much better than that.
Well I was getting no where with the original Habib Saidane CMC formula so I mixed in some Mike ware's cyanotype formula instead of pigment. Its like magic! For one thing, I learned that CMC melts at a respectively ungodly high temp...274C. It decomposes at that temperature rather than melt. So anything trapped in it will definitely survive temperatures much better than gelatine. Knowing that then makes it clear that the only way to clear it is thru dissolving in water. We may even be able to coat in CMC and then heat gun it for a nice finish... I will try that later. As a test, I overcooked this cyanotype, then I used ammonia to bleach it, then I used sulfamic acid to bring back the blue and stop the bleaching... All this without actually clearing and loosing chemicals in the wash. (Not my photo that I took myself of me)
There have been a few mentions of using CMC photographically but I haven't seen a single one where the process is explained and given out. Anyway, I made my 10% gum arabic beer look-alike.... I'm using a tiny spoon of sodium benzoate since I got no use for that now and its supposed to preserve things. Plus it does seem to harden the stuff in UV exposure. Then I went to make the 2% CMC mix.... oh my god, just leave it there for a day, that stuff does snot (pun intended) want to mix! So I grabbed a long plastic spoon and hooked it up to my drill. That works! Definely if you add more water eventually the CMC material will be more watery.
As previously mentioned, Habib Saidane has posted a video of his new process using CMC and Ferric ammonium citrate as the photosensitizer:
So I started thinking what else could we use as sensitizer. I found that Sodium Benzoate is cheap and could be a photoinitiator so I started testing it yesterday. Indeed, there's a reaction with UV light. I don't want to share amounts yet because I've barely started looking into this. But I was certainly able to change the solubility of CMC. The reaction is similar and suffers from the same oxygen inhibition that the citrate and oxalate from the Chiba process suffer. Yesterday I tested adding an acid. It turns out that if you add an acid, you create benzoic acid in the mix which can then absorb UV light. In my test I setup a bunch of samples with varying UV exposure and chemical mixes, and as you can see there are some clear winners where the stuff completely dissolved or stayed solid.