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BeLomo k-o 120 mm Projector lens on Canon EOS
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PostPosted: Tue Jun 12, 2018 10:11 pm    Post subject: BeLomo k-o 120 mm Projector lens on Canon EOS Reply with quote

Hello!

I've seen a thread about adapting an old projector lens, but since it's bit old I'm going to open a new one (hoping none will freak out Smile )

Soon I'll get a 120mm projector lens with a M65 mount.
To adapt it I was thinking about using a bellow (40mm to 150mm - Fotodiox), placing one M42 to EF mount and one M65 to M42 adapter (might 3D print it - not sure).

Do you guys think will allow me to have infinity focus? Is the bellow length enough for it?

Update: I've also found this one - but I'm afraid 42 to 92mm might not be enough

Thank you


PostPosted: Wed Jun 13, 2018 6:05 pm    Post subject: Re: BeLomo k-o 120 mm Projector lens on Canon EOS Reply with quote

MauroScattolini wrote:
Hello!

I've seen a thread about adapting an old projector lens, but since it's bit old I'm going to open a new one (hoping none will freak out Smile )

Soon I'll get a 120mm projector lens with a M65 mount.
To adapt it I was thinking about using a bellow (40mm to 150mm - Fotodiox), placing one M42 to EF mount and one M65 to M42 adapter (might 3D print it - not sure).

Do you guys think will allow me to have infinity focus? Is the bellow length enough for it?

Update: I've also found this one http://www.poenashop.top/highquality-m65-to-m42-lens-adjustable-focusing-helicoid-adapter-42mm92mm-p-4328.htm - but I'm afraid 42 to 92mm might not be enough

Thank you


Welcome here Mauro!!

Here, I have written about that here:

http://photographyoftheinvisibleworld.blogspot.com/2011/01/how-to-determine-length-of-focusing.html

and this is how it is mounted with 65mm helicoid:

http://photographyoftheinvisibleworld.blogspot.com/2015/09/how-to-modularily-mount-projection-or.html

This lens will certainly work for infinity focus as it has a rather large back focal distance.


PostPosted: Wed Jun 13, 2018 10:22 pm    Post subject: Re: BeLomo k-o 120 mm Projector lens on Canon EOS Reply with quote

kds315* wrote:
MauroScattolini wrote:
Hello!

I've seen a thread about adapting an old projector lens, but since it's bit old I'm going to open a new one (hoping none will freak out Smile )

Soon I'll get a 120mm projector lens with a M65 mount.
To adapt it I was thinking about using a bellow (40mm to 150mm - Fotodiox), placing one M42 to EF mount and one M65 to M42 adapter (might 3D print it - not sure).

Do you guys think will allow me to have infinity focus? Is the bellow length enough for it?

Update: I've also found this one http://www.poenashop.top/highquality-m65-to-m42-lens-adjustable-focusing-helicoid-adapter-42mm92mm-p-4328.htm - but I'm afraid 42 to 92mm might not be enough

Thank you


Welcome here Mauro!!

Here, I have written about that here:

http://photographyoftheinvisibleworld.blogspot.com/2011/01/how-to-determine-length-of-focusing.html

and this is how it is mounted with 65mm helicoid:

http://photographyoftheinvisibleworld.blogspot.com/2015/09/how-to-modularily-mount-projection-or.html

This lens will certainly work for infinity focus as it has a rather large back focal distance.


I don't think the back focal distance is that large. Looking at my adapted to M42 KO-120


The distance between the rear lens and the M42 is rather short. It is adjusted to infinity in Nikon, but still, you won't have a lot of space to work for adaptation on M42 or DSLR.


PostPosted: Thu Jun 14, 2018 7:20 am    Post subject: Reply with quote

I took mine out and set it into a 35-90mm Helicoid (65mm), and mounted on my Panasonic GH4 (mft).
The lens dives into the helicoid and the lens mounting ring from end of ring(= front of helicoid) to end
of lens is 22mm for infinity. This means end of lens to camera front plate is ca. 27mm

Indeed to mount it on a DSLR is needs to be quite close, as for mft the register length is 19.25mm
(Sony-E is 18mm), whereas Nikon-F is 46.5mm (for Nikon the lens end has to nearly touch the camera front).

Had overlooked that it was intended for Canon-EF, as Canon EF register is 44.0mm, so there is
27mm + 19.25mm = 46.25mm , then 46.25 - 44.0mm = 2.25mm between lens end and Canon EF mount.
Doable on a custom made basis (like yours Pierre) BUT NOT WITH A STANDARD 65mm HELICOID!!