The Cyanotype - Photographic Processes Series - Chapter 4 of 12

Sir John Herschel invented the cyanotype in 1842. The process depends on the
photochemical reduction of ferric salts into ferrous salts leading to the formation of Prussian blue, an iron-based pigment. The process was used sporadically throughout the 19th century and more frequently in the twentieth century for the reproduction of architectural plans and technical drawings, called “blueprints."
This project is made possible by a grant from the U.S. Institute of Museum and Library Services, grant number MA-10-13-0194.

[@OritMesilati]

תודה שקד על סדנא קסומה שהייתי בה אתמול. תודה על לימוד של טכניקה חדשה על לימוד מרענן ומקצועי ועל דרך חדשה שגיליתי

[@ericpa06]

Hi! I just found out your channel, and it's very good! You really undertand about movies and the history of motion pictures!

[@lochlannelson1901]

I guess Im randomly asking but does someone know a tool to log back into an Instagram account?? I was dumb forgot the account password. I would appreciate any help you can give me!

[@harveyjacoby3910]

@Lochlan Nelson Instablaster ;)

[@lochlannelson1901]

@Harvey Jacoby I really appreciate your reply. I found the site on google and I'm trying it out now. Looks like it's gonna take a while so I will get back to you later with my results.

[@lochlannelson1901]

@Harvey Jacoby it did the trick and I actually got access to my account again. Im so happy! Thanks so much, you saved my account!

[@harveyjacoby3910]

@Lochlan Nelson You are welcome :D

[@ghennethr.cristianob.b.8040]

What special Blue! My Blue Mood!

[@toddoroi4947]

Any idea why homemade cyanotype paper is yellowish and turns grey-black and commercial paper starts out blue and turns light grey-green.

[@TheStockwell]

Based on my experience with both, I'd guess because the homemade paper is fresher while the commercial, prepared paper might've been manufactured and in storage for who-knows how long. Also, I've read that if your emulsion is blue when it dries, you have impurities in the paper which will affect the quality of your prints.

[@logeshwaranrk]

Is, Sir John Herschel was the one coined the term "photography"? I found this information in Cosmos:A spacetime odyssey (s1e3 hotstar)

[@davidgjeffroy7239]

Have 2 family daguerrotypes: mother & her parents. 1930s? Among my treasures! DGJ.

[@TheStockwell]

Yes, also the terms "negative" and "positive" as used in photography.

[@samiteshbhattacharjee9566]

I liked the video

[@joester610]

I'm interested in learning the history of the photo at 3:00. If anyone has anything, i'd love to hear it; even if this comment is years old.

[@simperingham]

The photos in the video are probably from the Eastman collection. You could see about looking up their catalogs. Otherwise I’d email the Eggwork Company and ask if they have the files used to make the video. They’re maybe named there.

[@joester610]

@@simperingham Thanks for the information. I think what fascinated me about it originally is the amount of life and depth this photograph showcases in each individual despite its age. They are all people who are likely long gone, yet they are so well preserved in that one still image. My curiosity stems from the question: does anyone even know who any of them were?

[@lauradevries6185]

How could i produce a negative image by myself?

[@elielmendes2443]

Laura De Vries, I think a transparent plastic printed in a laser print would work.

[@Foxglove963]

Laura De Vries. Use a large format camera for film.

[@___-vz7mp]

Yes I know this comment is 7 years old, but- Just do a regular Cyanotype photo, but use a clear plastic substrate for the negative to be on. All photochemical cameras produce negative images. Take your negative cyanotype image on the plastic, then put the developed negative plastic image on top of an undeveloped coated paper (or other substrate). Then have it developed with the negative as the ‘mask’.