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Schott and other optical glass makers sell their glass as raw glass cubes. And there are water jet cutting machines can cut glass transparent.
I thought we can cut least two different refractive...

I think they spray antibacterial - antidirt silver iodide nano particle solution on to surface and this coating been activated by sun everyday. Can we use this spray as our wetplate emulsion on glass...

I remembered my research on colorants and different crystal shapes of silver in glass was creating wide range of colors , pyramid shaped crystals were creating one color and the sphere and so on. And...

Mark , really interesting , lets wait what she says ?

Greg , can we say that silver or silver iodide crystals caused these colors , if they are in really crystal form ?

Mark , What do you mean with mirroring ? Is it a scientific term ? Thanks.

Umut

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Hello friends , is this glass negative colorful or because of backlighting ? I found pinks , blues , purples around ! If it is really colorful , why is that ?

I bought 5 rolls of Adox CHS 100 II ISO 100 and want to develop it with best diy developer formula in my hand. I love weston and want to use his formula. Low contrast , high acutance and low ugly...

I have just added the document herebelow !

Might it be 450 ml water with 1 to 30 ratio at 1/2 liter weston dilution ? It writes 425+15+15+45 =525 ml but it is total 500 ml ?

Thank you. I try to remember a few details on wet plate fine grain but no success. Can you help me to put together ? I had been read a research paper from russia with micrographs of the emulsion....

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Hello there , I attached two pages from an article which tries and compare textile pieces with todays technology and wet plate collodion. At wetplate samples , even smallest light...

Hello all, I tried to learn something usable from orson welles citizen kane and conducted a short quick mtf software analysis. I stumbled in to a result which I could not understand anything. Can you...

Do you have any image or link to example of use of leitz hektor 13.5 f:4.5 as a Large Format 9x12 cm negative size making lens ?

umut

I have just finished watching videos about uranium , thorium extraction from rocks. There are lots of chemicals been involved and for each chemical , there is a magnificient colors generated.
I...

Thank you very much indeed. This is very interesting. How someone inspects the development like Weston ? How to see the negative in dark ?

additional later post to add here :

...

I want to learn whether Edward Weston was using or not using stand development , or may be he cut the development time half or extend two times more ??
What he was doing ?

Umut

Can you please tell me what is the ABC Pyro Edward Weston's special dilution ratio, film development times used by Edward Weston.
What is above developer and Weston dilution advised, normal...

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I found these technical drawings.

I want to ask what are the uses of rear , ziggurat like flat glass blocks ?

Can we make a lens out of these kinds of flat blocks ?

Thank you,

It does not sound reasonable to have different psfs for each spot in scene.

If it is true , it would be utmost difficult to design an lens.

If I am not wrong , psf is a frequency filter which...

ps. When I think more , psf might be the impulse response of the optical system , as impulse response used at violins , it must be a frequency response filter of the system. I dont know if there are...

German music composer Stockhausen told one time , the root of the all sounds are the few short impulses. When you compose few short notes for example din don and when you record that noise to the...

An German family business and their liquid glass nano protective coating invention inspired me. They mix alcohol and silica nanopowder and spray on surface and it creates a glass surface when alcohol...

Da Vinci spent 40 years for mona lisa because each spatial paint layer took 1 years to dry.

I saw someone made platin prints on glass plates and stacked them , for each change of light , print...

Jac,

I think you mentioned that pyramid lens which was a document lens where ibm parc published attached paper on it. Now the question , does it solve the zero back focus distance problem ? I...

Thank you Jac and all,

I think I saw an french lens with truncated cone glass at the back side. How does it help ? Is it the only solution ?

I think coming rays hitting to cone , focus to cone...

I want to order laser or water jet cut two cylinderical lens elements from single block of plexiglass or glass without need of mount because remaining block would carry the elements and could be...

Which is true ? A,B,C OR D ?

If I attach janpol lens in front of a camera and If I only move yellow filter in

I dont have an enlarger and I could not imagine answers.

A-- I could see a...

I found optometrists measure higher order faults of eye and print 3d phase plate eyeglass lenses to correct them. If the 3D printing is good enough for eye , why not for camera or painters ,...

Thank you very much jp.

I tried but shipping 35 euros for single element lens , rip off , I need other source.

Umut

Hello ic-racer , I can build a box , glass and paper holder. All fixed , all focus would be done to move the box. No bellow , no movement.

Umut

88mm Dia. x 750mm FL, Positive Meniscus Lens, Grade 2

47mm Dia. x 700mm FL, Positive Meniscus Lens, Grade 1

I think these are the suitable ones for 24 inches , which is better grade 1 or 2 ?
...

Hello there,

I want to take my mother and sisters portraits with 20x24 Fomabrom Grade 3 Matte Paper Negatives and contact on to the same paper.
There are 10 papers for 70 dollars at Freestyle and...

One of my APUG friend helped to me to buy one of the last internet Diafine trades.

I will to bring it to university lab to analysis than to other one to check the results.

Once Photo Engineer...

I thought a idea which I have no idea it was done before.


At half toning , you have two films , first photograph film and second is resolution screen. Resolution screen decomposes the photograph...

I read an mit research years ago do simulating one reference image noise in to other.

Is there a library plug in simulates the classical analog materials noise in to your image ?



Umut...

I read at APUG that film is superior to digital because film records everything with molecular level. I dont know how much of these molecules records the photograph but I developed an idea.

As...

ic-racer,

Thank you for your reply .

Do Leica relief image is a interplay between saggital and tangential lines ?

Could you please write an tangential and saggital contrast change code for...

As You are , I am aware of tangential and sagittal contrast - MTF - curves.

And I saw a optical art piece where the artist had put an 45 degree rotated triangles in rows of aligned triangles.I...

Hello Heinrich,

Only % 10. Thats good news , what is the contrast index of % 10 underdeveloped film ? And What is the CI of non treated film. I am asking for tanol or other pyro developer.
...

Hello Heinrich Voelkel,

Thank you for your help. As clarifying things for non 35mm users , Polypan F and Pan F is not the same film. Pan F is Ilford brand , Polypan F is - noone knows the source -...