A wide circa 1.8/16 lens taken from InFocus video projector

alex ph · Joined: 16 Mar 2013 Posts: 1709

I've got for cheap a video projector InFocus X6 from the late 2000s, cheap because it was outdated by today's standards and also because its DLP chip was burnt. I disassembled it and took its lens to adapt it to Sony Nex fitting it into a Chinese helicoid.

The lens' specification is nowhere announced, so I evaluate its characteristics in comparison to other lenses having a clearly indicated aperture and focal length. Basing on this comparison, I suppose it has the FL of 15mm or 16mm and the aperture of around f1.8. the lens convers APS-C with very limited vignetting.

I am pretty much amazed with the picture quality (sharpness, colours) and with its well controlled rectilinear distortion. Its bokeh looks nice too. The field curvature is much more pronounced, but it is not reduced to fuzziness off center. If you refocus on the corners, the corner subject remains perfectly sharp and undistorted. Pretty obvious CA in contrast light margins, but nothing too nasty.

Here are some samples taken at different distances.

#1 Sooc jpg, near field

#2 Near field again

#3 BW taken from the blue channel

#4 Counter light, exposure tweak

#5 CA visible in lantern lines, but good rectangular geometry on the whole

#6 Mid-range in focus and far field OOF

#7 Just a street shot

#8 A landscape shot

#9 A night shot

Ultrapix · Joined: 06 Jan 2012 Posts: 608 Location: Italy

Very interesting, by the way the right side is way sharper, maybe something wrong in the adapting process?

alex ph · Joined: 16 Mar 2013 Posts: 1709

You are right, the PVU tape of which I made the layer to fit the lens into helicoid makes a slight tilt. I tried to level the lens better vertically. Here is the result.

#1 Sooc jpg

#2 Processed in Nik Silver

Ultrapix · Joined: 06 Jan 2012 Posts: 608 Location: Italy

Better, indeed, and really good. I remember a similar experiment by Jangreenhalg some time ago. Those lenses may be interesting

alex ph · Joined: 16 Mar 2013 Posts: 1709

Thank you for your feedback!

I am thinking over the way to better fix the lens in the helicoid, as it has a tendency to tilt slightly in the soft sticky ribbon.

Here are some more shots showing the lens' character with Sony Nex. Slight exposure and contrast tweaks are applied to colour shots, harder ones to BW processing.

#1

#2

#3

#4

#5

alex ph · Joined: 16 Mar 2013 Posts: 1709

I'd like to add a couple more photos from this lens, just for fun.

#1

#2

#3

Whomstevest · Joined: 19 Oct 2020 Posts: 7 Location: Melbourne Australia

What's the rough flange distance of the lens? Got a photo of the setup? Shots look very nice!

alex ph · Joined: 16 Mar 2013 Posts: 1709

Thank you for your appreciation. I dismantled all the plastic rings coming from the projector and left only the metal barrel. Following the link I gave in the first post you may see how the lens looked like when it makes part of the projector. And here is the final setup:

It is a 17-32m Chinese helicoid put on extra slim M42 ring. I added a №3 M42 extension ring in order to put the lens deep inside, held with a band of a sticky foam, and to keep it from touching the camera internals.

This way the moving focus part of the lens is secluded inside the helicoid, but you still may zoom the lens with its front part. Zooming capability is really limited, 1.1x or 1.2x, so I do not really use it.

The distance from the rear lens to the Sony mount flange is about 8mm or 9mm at infinity. I have no tool for a precise measurement in this case, and a quick caliper blow allows only an approximate view. Add 18mm of Sony E mount flange, from which follows the lens has 26mm or 27mm of flange distance.

kds315* · Expire: 2021-03-09