Janpol Lens, MF, Control of Color? How does all work ?

Mustafa Umut Sarac · May 28, 2015

I am asking a theorical question or if you want to answer with numbers , examples , here is your chance .I was thinking to control colors of my photographs and Our ic-racer pointed JanPol lenses.Here we simulate the lens and the MF Back Camera. What would I see when viewing from finder if I rotate the controls ?Strange color combinations or increasing of red , ...? Could you please describe me ?

If I order today , it takes a month to reach me.

Umut

ic-racer · May 28, 2015

The filter, marked as F is situated over the aperture, marked with D letter.
From the N point exits a divergent ray of light into which you insert the filter.
After exiting the lens, rays focus on the positive in the point marked as P. These
are filtered (the lined area) and non-filtered rays. The intensity of the colour
of the positive depends on the ratio between the filtered and non-filtered rays.
A similar light path from the N1 point to the P1 point proves that the whole
image projected on the positive is equally coloured and the degree of the
colouring depends on how deep the F setting point is positioned. --- http://www.lenstip.com/index.php?art=132

Mustafa Umut Sarac · May 28, 2015

Thank you ic-racer.

My grey cells tells me , that lens creates a singular color with controls. I did not use an traditional enlarger but I was a antique minilab operator and I dont have any experience on what can color enlarger do or what is needed
.
ps. I am wrong , lens creates a combination of normal color plus filtered color. There might be still active colors in the picture. I thought it transforms in to monochrome but I was wrong. This is an excellent lens , with little bit retouching , you can get excellent results.

I think that kind of lens could be used as a multispectral filter for remote sensing.

Can I use that lens to create every color possible with cmy space ?

And is there metallurgy , mineralogy remote sensing filters within that cmy space ?

Umut

ic-racer · May 28, 2015

Mustafa Umut Sarac said:
Can I use that lens to create every color possible with cmy space ?

And is there metallurgy , mineralogy remote sensing filters within that cmy space ?

Umut

Theoretically all colors. You can use graded levels of Yellow, Magenta or Cyan individually or any combination of TWO. Not all three together, but that is OK because all 3 together is just neutral density.

A system for sensing color is simply three 'standard' photodiodes each covered with a little color separation filter (special fade-resistant Wratten is best, but not available in green as seen in the lower picture of the faded green Wratten filter). Many color densitometers and closed-loop computer controlled color enlargers use that method.
(there was a url link here which no longer exists)

Mustafa Umut Sarac · May 28, 2015

Thank you very much ic-racer , I still dont know your name , its a pitty to call a person as integrated circuit

I saw some remote sensing filters which were nearly transparent with pinkish sheen. And there is curves.

How can we transform janpol technology in to a variable strange looking transmission filters curves ? Is it possible ? Do you have an idea,Is JanPol filter, a bandpass transmission filter or how to do that ? I think at 70s , they might want that technology before LCD.

Thanks,
Umut

Mustafa Umut Sarac · May 28, 2015

I found linear variable vis bandpass filter for 1500 dollars , bandpass filters at alibaba are 2 to 20 dollars range !

Tell me ic racer , which bandpass filters filters a light with variable transmission. I will write to china but lets hear from america.

Umut

Mustafa Umut Sarac · May 29, 2015

this is cross posted at lfp forum.

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 monochrome cyan image where all other color information lost ?
B --I could compose a filter color to capture for example distant marina fenders as orange and for a painterly localized high chroma color.
C-- I could capture many images to stitch and recolor at photoshop.
OR
D-- I could see a image where there is heavy cyan cast but all the other colors are remaining in the glass window and
film ?

Thank you .

Umut

ic-racer · May 29, 2015

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

You image will look like this (it will look like there is a yellow filter in front of the lens).

darkosaric · May 29, 2015

Janpol lenses are relatively cheap in Poland: 40-50€.
On ebay they are much more expensive.

Janpol Lens, MF, Control of Color? How does all work ?

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