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Freelensing with 35KP-1.8/140mm Russian projector lens
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PostPosted: Sat Nov 22, 2014 12:16 pm    Post subject: Reply with quote
kds315* wrote:
It basically confirms that KO-140 is a coated Petzval element lens.
The Resolution figures have to be understood with a grain of salt,
it is not up to today standards. And it is lines per mm, not
line pairs per mm, so take 50% of that as a figure ...



Thank you Klaus for your help.
I will have to work out a tripod mount for this lens.
It really needs it.
OH


PostPosted: Sat Nov 22, 2014 12:27 pm    Post subject: Reply with quote
Just checked again and your lens is a 4 element type, not a 6 element.
Maybe shine a light in it and count the reflections. Are you really sure it
is 1.5 Kilogram weight and not 0,9??


PostPosted: Sat Nov 22, 2014 3:56 pm    Post subject: Reply with quote
Just love all the shots Tom.


PostPosted: Sat Nov 22, 2014 8:08 pm    Post subject: Reply with quote
Oldhand wrote:
Pancolart wrote:
And some data:


Thank you Pancolart for the specs sheet.
My german(?) is zero but I think I see lines per mm at 80 presumably for the centre.
The mass is wrong however.
0.778kg is only about half of its weight.
It is very much heavier @ 1.5kg
Gratias
OH


Could be different body variant then yours. Yours: thicker metal.


PostPosted: Sat Nov 22, 2014 10:01 pm    Post subject: Reply with quote
Yes, definitely 1.5kg.
Definitely 6 reflections
Here it is next to a Helios 44-2 for comparison.
OH




PostPosted: Sun Nov 23, 2014 2:13 pm    Post subject: Reply with quote
Thanks for showing it Thomas. Quite a heavy beast indeed. Maybe it is brass and not aluminum housing.

So you have a version which is unknown to me (I did some homework before I bout a few in Russia
through a friend).

6 reflections only? That would make a 3 element lens ... must be many more (I count a total of 12 on
mine; some are barely visible, I use a LED lamp and shine inside)

Last edited by kds315* on Sun Nov 23, 2014 7:59 pm; edited 1 time in total


PostPosted: Sun Nov 23, 2014 4:51 pm    Post subject: Reply with quote
Indeed yours is heavy model. Bellow is the usual model with thin metal body.

Abbazz wrote:


You're welcome, Laurence. This thread on the Russian forum is full of beautiful images. It's also very dangerous because it's full of tips about wonderful lenses and it makes you want to buy them all.

Because of this thread, I have just bought three cheap but interesting lenses on eBay.

First, a 35-KP 140/1.8:


Then a 35-KP 120/1.8:


And a KO-140M 140/1.8:


These lenses were designed for cine 35mm projectors and were made at the Belarus Optical factory in Minsk. All three seem to be of Petzval formula, a very interesting optical formula designed in the 19th century and mainly used for portrait. Here is the specs sheet for the KO-120M:



You can see it resolves 90 lp/mm in the center of the frame and 45 lp/mm at 12mm from the center. Of course, these figures are measured wide open, because projector lenses have no diaphragm! The lens coverage is 18.2mm x 23.2mm (the size of a 35mm cinema frame), which is enough for a crop format camera like my Pentax K-10d.

The lenses should arrive here in Brunei in about two weeks, I cannot stand the wait...

Abbazz


PostPosted: Sun Nov 23, 2014 9:27 pm    Post subject: Reply with quote
kds315* wrote:
Thanks for showing it Thomas. Quite a heavy beast indeed. Maybe it is brass and not aluminum housing.

So you have a version which is unknown to me (I did some homework before I bout a few in Russia
through a friend).

6 reflections only? That would make a 3 element lens ... must be many more (I count a total of 12 on
mine; some are barely visible, I use a LED lamp and shine inside)


Ah yes, two sets of six reflections but offset and one set would be interspaced with the other - I guess front and back of the glass elements shown as separate sets - so 12 reflections - my mistake
OH


PostPosted: Sun Nov 23, 2014 9:45 pm    Post subject: Reply with quote
Oldhand wrote:
kds315* wrote:
Thanks for showing it Thomas. Quite a heavy beast indeed. Maybe it is brass and not aluminum housing.

So you have a version which is unknown to me (I did some homework before I bout a few in Russia
through a friend).

6 reflections only? That would make a 3 element lens ... must be many more (I count a total of 12 on
mine; some are barely visible, I use a LED lamp and shine inside)


Ah yes, two sets of six reflections but offset and one set would be interspaced with the other - I guess front and back of the glass elements shown as separate sets - so 12 reflections - my mistake
OH


Yes, exactly. Two sets of reflections a bit spaced sideways from another.


PostPosted: Mon Nov 24, 2014 5:21 am    Post subject: Reply with quote
Mine is exactly 700 grams (the one that can be dismantled)


PostPosted: Mon Nov 24, 2014 10:33 am    Post subject: Reply with quote
лин/мм means lines/mm, not lp/mm, so actual resolution is 2x less.


PostPosted: Mon Nov 24, 2014 11:00 am    Post subject: Reply with quote
CuriousOne wrote:
лин/мм means lines/mm, not lp/mm, so actual resolution is 2x less.


Yes, that is what Klaus said too.
Nevertheless it has plenty of potential from the little that I have used it.
I have figured out a tripod mount - so next the connections to the camera etc.
Cheers
OH




PostPosted: Mon Nov 24, 2014 9:05 pm    Post subject: Reply with quote
Still free-lensing.
One more from a very bad bunch - too much extraneous light.
OH



PostPosted: Mon Nov 24, 2014 10:17 pm    Post subject: Reply with quote
Looks very promising that result!

The tripod clamp is neat, but it will collide with the focusing heliocid (if you go that route I proposed...)


PostPosted: Mon Nov 24, 2014 10:23 pm    Post subject: Reply with quote
kds315* wrote:
Looks very promising that result!

The tripod clamp is neat, but it will collide with the focusing heliocid (if you go that route I proposed...)


Thanks Klaus.
Hmmmmmm .......... I thought that with the tripod collar foot facing forward I would avoid that.
I will have some trial and error I am sure in getting this fully operational.
Interestingly, there is a colour change in this image that I can't explain.
The stamens were a charcoal grey as well as the shadowed background.
It came out as you see - a kind of maroon ........
The yellows are exact however.
OH


PostPosted: Mon Nov 24, 2014 10:39 pm    Post subject: Reply with quote
Oldhand wrote:
kds315* wrote:
Looks very promising that result!

The tripod clamp is neat, but it will collide with the focusing heliocid (if you go that route I proposed...)


Thanks Klaus.
Hmmmmmm .......... I thought that with the tripod collar foot facing forward I would avoid that.
I will have some trial and error I am sure in getting this fully operational.
Interestingly, there is a colour change in this image that I can't explain.
The stamens were a charcoal grey as well as the shadowed background.
It came out as you see - a kind of maroon ........
The yellows are exact however.
OH


That color change might be due to CA I would guess as the focus plane is razor think especially so close (which is waaayyy out of the lens definition it was computed for, so no wonder...)

Your lens has some 50-60mm back focal distance, so deduct the camera register from that, the optical adapter length and you'll see soon that the lens has to dive in quite deeply into the focusing helicoid. So it may or may not work...


PostPosted: Mon Nov 24, 2014 10:46 pm    Post subject: Reply with quote
kds315* wrote:
Oldhand wrote:
kds315* wrote:
Looks very promising that result!

The tripod clamp is neat, but it will collide with the focusing heliocid (if you go that route I proposed...)


Thanks Klaus.
Hmmmmmm .......... I thought that with the tripod collar foot facing forward I would avoid that.
I will have some trial and error I am sure in getting this fully operational.
Interestingly, there is a colour change in this image that I can't explain.
The stamens were a charcoal grey as well as the shadowed background.
It came out as you see - a kind of maroon ........
The yellows are exact however.
OH


That color change might be due to CA I would guess as the focus plane is razor think especially so close (which is waaayyy out of the lens definition it was computed for, so no wonder...)

Your lens has some 50-60mm back focal distance, so deduct the camera register from that, the optical adapter length and you'll see soon that the lens has to dive in quite deeply into the focusing helicoid. So it may or may not work...


Thank you again.
Fun times ahead .............. Very Happy
OH


PostPosted: Mon Nov 24, 2014 10:55 pm    Post subject: Reply with quote
Yep, but well worth it, considering the great results that lay ahead of you Wink


PostPosted: Mon Nov 24, 2014 11:33 pm    Post subject: Reply with quote
One more at full aperture and up close and personal.
OH



PostPosted: Wed Mar 18, 2015 1:49 am    Post subject: Reply with quote
Nice images, congrats!

Did you have any success in making an aperture for this lens?

I am going to get a bell & howell 16mm 1.2/50 lens. Did not find any description of its optical formula. I thought a cardboard circle on the front lens could be enough. But that does not work like that, right? That only darkens the light but does not sharpens the image?

I tried to find some descriptions of successful experiments with mounting an aperture to projection lenses, here and in the free net. Surprisingly, I found nothing. Or I just used wrong keywords?

Will be glad to have your comments and good examples.


PostPosted: Wed Mar 18, 2015 3:13 am    Post subject: Reply with quote
alex ph wrote:
Nice images, congrats!

Did you have any success in making an aperture for this lens?

I am going to get a bell & howell 16mm 1.2/50 lens. Did not find any description of its optical formula. I thought a cardboard circle on the front lens could be enough. But that does not work like that, right? That only darkens the light but does not sharpens the image?

I tried to find some descriptions of successful experiments with mounting an aperture to projection lenses, here and in the free net. Surprisingly, I found nothing. Or I just used wrong keywords?

Will be glad to have your comments and good examples.


No, I have only used the home-made cardboard aperture disks so far.
It is still a project for the future.
OH


PostPosted: Sat Jun 13, 2015 1:57 am    Post subject: Reply with quote
http://forum.mflenses.com/ko-140m-140mm-f1-8-projector-portraits-sony-nex-7-t71552.html


PostPosted: Sat Jun 13, 2015 9:12 pm    Post subject: Reply with quote
I did play more today with this lens, on highlighted areas CA is very significant, but.. lens is brutal sharp and bring nice details as well, so CA is little price and in same light even my Zeiss lenses produce CA well , so a rare opportunity to get powerful fast lens on low cost . Lot better option than any other under 500 USD


PostPosted: Sat Jun 13, 2015 11:59 pm    Post subject: Reply with quote
I am not getting the same excellent results as you are Attila, and at wide open it does have the CA issues.
Mine seems to need some aperture control to bring out its best.
Here are a few from this morning at f1.8.
OH






PostPosted: Fri Sep 01, 2017 1:19 pm    Post subject: Reply with quote
Just cut rear 12mm on it. Russians know how to build tanks, it is like fitness to use it without tripod. I also have KO140M, which is about 50% lighter. Cheerz!

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