Adapting projection lenses

[nigbat]

I have bought a couple of old Kodak slide projector lenses - which have the indisputable merit of being very cheap. Unfortunately, they have a flat focusing rack which is an integral part of the mount. Does anyone have any tricks for adapting this on to a helicoid ?

(I had considered removing the lens assembly from the tube mount, but it seems sealed in, and there is no obvious way of doing so.)

 

[GnarlydogOZ]

I have bought a couple of old Kodak slide projector lenses - which have the indisputable merit of being very cheap. Unfortunately, they have a flat focusing rack which is an integral part of the mount. Does anyone have any tricks for adapting this on to a helicoid ?

(I had considered removing the lens assembly from the tube mount, but it seems sealed in, and there is no obvious way of doing so.)

I have adapted a few projection lenses but not exactly a Kodak one. I usually just glue a M42 thread onto the back of the lens and put it on bellows to see if it is worth actually adapting properly. Not that leaving it simply on bellows doesn't work but sometimes focusing can be a bit tricky (bellows have a rather coarse focusing movement). Once I establish what "flange distance" I need I try to find an old lens body where I remove the glass (usually mouldy/cracked) and use its helicoid. Or, find a helicoid on eBay that has the correct spacing, that I determined while my projection lens was on the bellows. If I didn't have bellows I could freelens first to get roughly close to know what I need and then maybe make something out of PVC pipe fittings. It all sounds rather ghetto but I have made some great images that way. If you think of it, Lens Baby with its floating/swivelling mount is pretty wobbly anyway. Or the old bench cameras with all the swivelling and tilting... nothing perfectly aligned there either?

16mm film projection lens adaptation, test mode only; later transferred into a body of a 35mm lens

 

[nigbat]

Thanks - just realised (duh) that a thinnish M42 extension tube will fit >inside< the projection lens tube, which deals with the problem of the sticking out bit on the outside of the tube.

Now just need to source some suitable (preferably reversible) glue for the job.

 

[GnarlydogOZ]

Thanks - just realised (duh) that a thinnish M42 extension tube will fit >inside< the projection lens tube, which deals with the problem of the sticking out bit on the outside of the tube.

Now just need to source some suitable (preferably reversible) glue for the job.

if it's metal I use epoxy glue (JB Weld) since to remove it I just have to heat it up a bit. with a hot hair drier or heat gun.

If it's plastic I am a bit more cautions and use polyurethane sealant (Sikaflex). It's like silicon but much easier to remove as residue dissolves with methylated spirits.

 

[nigbat]

[No message]

 

[nigbat]

Sorry - don't know what happened to the text of my previous reply.

Have ordered some glue & will report back - thanks.

 

[nigbat]

Here's the glued in mount, using a 50mm M42 extension tube wh:

The lens is a Kodak Ektagraphic 124mm f2.8. Here's a test shot - really quite soft ( I need to fabricate a lens hood, as the large front element is barely recessed at all), not massive resolution and strange but quite appealing bokeh. Might make a nice portrait lens.

 

[GnarlydogOZ]

Here's the glued in mount, using a 50mm M42 extension tube wh:

The lens is a Kodak Ektagraphic 124mm f2.8. Here's a test shot - really quite soft ( I need to fabricate a lens hood, as the large front element is barely recessed at all), not massive resolution and strange but quite appealing bokeh. Might make a nice portrait lens.

did the exact same thing to a Russian Triplet 78mm projection lens that has the same barrell. I cut down the plastic tube to a minimum and then glued the M42 thread on: I wanted a short barrel that I can use on bellows. For the hood I did the same: I picked a cheap UV filter that would be just slightly too small to fit on the end of the lens, removed the glass and then filed the internal diameter of the filter ring to slip snugly over the end of the lens. A bit of glue and now I can attach a lens hood. Looks "factory"

 

[widgetbox]

I'm feeling most unworthy. Most daring thing I've done is fit a LTM adapter to my little Sony.

 

[GnarlydogOZ]

I'm feeling most unworthy. Most daring thing I've done is fit a LTM adapter to my little Sony.

 

[Lightshow]

I thought I posted a reply in this thread...

My favourite projector lens is the Meopta Meostigmat 70/1.4, it shares its optical formula with the Helios 40(85/1.5) and the CZJ 75/1.5, it has some very swirly rendering.

https://www.flickr.com/photos/lightshow-photography/tags/meoptameostigmat7014/

http://forum.mflenses.com/meopta-meostigmat-1-4-70-on-ff-and-nex-via-vnex-t55218.html

Mine is permanently mounted to a V-NEX, see link below.

I'm feeling most unworthy. Most daring thing I've done is fit a LTM adapter to my little Sony.

 

[nigbat]

I'm feeling most unworthy. Most daring thing I've done is fit a LTM adapter to my little Sony.

 

[GnarlydogOZ]

I was worried the "C" designation (for curved field) on the Kodak (Carousel) Ektanar 102mm f2.8 was going to be unusable but it turns out very pleasing to me. I was after the coveted Trioplan bubbles and I got them at a 1/100 of a the price of the exotic Meyer Optik lens.
Mounted on bellows with a simple M42 ring glued to the back of the lens I was able to get this

increased contrast and a bit of sharpening, minimal crop

 

[Tom Caldwell]

I'm feeling most unworthy. Most daring thing I've done is fit a LTM adapter to my little Sony.

 

[GnarlydogOZ]

My recent discovery/invention has been with the Olympus evf which has a reputation for sunburn causing spots on the lcd. The longs story is that I have found that a little blind covering most of the object lens in the evf will actually not prevent the evf being used normally.

I did post this with illustrative photographs on the M4/3 forum but it went down like a lead balloon. Maybe the more enquiring adapted lens users might be a little more interested in this optical phenomenon.

My guess is that big bright and dangerous to know the sun evf units are so interestingly popular that no one is going to get anything between the eye and the lcd even though it seems a worthwhile insurance policy, is dead simple to implement, and does not seem to make any real difference to usefulness.

 

[nigbat]

I second the request for that link (I guess it got an adverse reaction because people took it as a criticism of their equipment choice... silly, I know).

As far as enlarger lenses are concerned, a decent M42 helicoid is great, as it gives you a variety of cheap options for very effective macro/short distance shooting. As an example, here's a very cheap lens which gives quite acceptable (& sometimes excellent) results on M4/3:

E-Lucky 75mm f3.5 enlarger lens

This enlarger lens was discussed recently on the Kodak Ektar thread. It's available very cheaply - I think I paid around £10 for mine - and while it's apparently only a three element lens, it seems to perform pretty well on M4/3 (less well on larger formats). It seems to resolve impressive...

www.dpreview.com

 

[nigbat]

Not yet got around to finding a hood for it, but the Ektagraphic 124/2.8 seems to do OK in sunlight, if you like soft images:

 

[GnarlydogOZ]

Not yet got around to finding a hood for it, but the Ektagraphic 124/2.8 seems to do OK in sunlight, if you like soft images:

hmm, so it seems that projector lenses are on the soft side. My Russian Triplet 78mm f2.8 at the beach yesterday:

Triplet 78mm f2.8

 

[nigbat]

Not all of them - the modern ISCO lenses, for example, can be tack sharp.

I very much like the rendering of that Russian one.

 

[nigbat]

Interesting, but slightly impractical lens, as the register distance is so short that I can't get it to focus beyond about a foot and a half.

A clue to that is the spring loaded (!) rear element, which was apparently designed to make it a bit easier to thread the film between the light source and the lens - obviously not much in the way of clearance...

Fortunately I got a very cheap (couple of quid) copy, with fungus (easy to clean), and significant separation (does it have a cemented front element ?), so the limited use isn't a huge disappointment. Unless you're a dreamy macro enthusiast, I wouldn't bother with this one.

Rendering is quite nice; just about covers M4/3; reasonable detail in the centre only -