‘Scope Lens Query

[Gary A. Hoselton]

On this website, go to Warehouse>Tips>Focusing Anamorphics. Works fine. But, again, your throw may be too short for your anamorphic adapter. I have a 35 foot throw, and the gold Schneider anamorphic adapters work fine for me.

My screen is less than 2.35 wide for 1 high, but fortunate that local cinema equipment supplier has boxes of modern Isco and Schneider removed lenses so I borrowed a few till I homed in on best fit for scope width and then bought a fairly matching pair from them (I do changeovers). I adjust masking up and down to frame the picture.

Yes, you need a separate aperture plate for scope. Don't try to modify your flat plate, find another one and file away on it, remembering that prime lens reverses the image from aperture plate to screen, so upper right on screen is lower left on aperture plate when you start filing. Run the RP-40 loop and file to fit. If you overfile, tap the spot using a 1/4" punch to expand the brass and then file carefully till perfect. Great project!

[Mark Gulbrandsen]

You don't actually focus a scope lens, you are adjusting it's astigmatism.

[Steve Pike]

Thanks all again. I have a separate scope aperture plate, it needs a bit of filing down on one side (the original location had a bit of a rake and projector was slightly off centre).

I’ve found the following on eBay:

https://www.ebay.co.uk/itm/Lens-Schn...-/274885020851

this seems to be a brand that has been recommended in this thread, at at a reasonable price too. Thoughts?

agin, really appreciate everyone’s help.

[Gary A. Hoselton]

That is an integrated prime/anamorphic, which does a good job. Being integrated, there is no dust to clean between the traditional separate units. The prime is 67.5mm. That will make a slightly larger picture than the 70mm one you have purchased. Probably should wait till you've tested with the 70mm, to see if a slightly shorter prime will work for you. And, I've no knowledge how short a throw the integrated lenses will accommodate, and there is no head-on view of the front where the adjustments are.

To file the aperture plate, clamp it in a vise. Use a new or very good finer file, small rectangular is what I use. File a little, then put back in projector and check against RP-40 film loop. Back and forth till you get it just right. Probably take ten minutes or so. If your RP-40 loop is a bit dry, coat very lightly with FilmGuard or a lightest oil so don't get wear scratches each side of the perforations from the rails in the gate/trap.

[Sean McKinnon]

Ten Minutes? I hope you are not talking from a pin hole or new undercut plate???

[Gary A. Hoselton]

Mighty good, Sean. No, he said he has a 2.35 aperture plate filed for a tilt plus projector off-center so keystoned, so he just has to trim up the edges a bit. Now, if it was overfiled so he has to pound some of the brass back into the aperture, will take a bit longer. Better allow a half hour prep time, then the ten minutes of fun work.

I have a couple of Simplex XL aperture plates with ovals in them. Could they have been for spotlights or such?

[John Eickhof]

steve, the kowa suffers from old age...it is foggy because early anamorphics like the kowa and b&l had the glass elements glued together, thus as they age the glue fogs up, newer lenses are air gapped and will not have that issue, plus it looks like the corners are vignetted, what projector are you using? if there is a 3" extension tube between the primary lens and the anamorphic, the picture is clipping on the barrel causing the corners to be dark, to check, remove aperture plate and put flat lens in and see if outer corners are dark, if you look into the front of the lens see if the light is hitting the barrel of the lens, if it is then its vignetting and you need to remove any extension tube on the flat and the scope, some older american machines like the super and e7 it was necessary to remove the outer lens clamp when using lenses of 3 in efl or shorter. kollmorgen made a special run of lenses from 2in to 3in efl with two extra elements and extended design just to clear the early double clamped lensholders. i suggest you find a full size anamorphic attachment like isco or schneider and that should greatly improve pix quality as well as vignetting. i have many excellent isco and schneiders if you cnt find one close to your location.

gary, if your plates have 1/4" round holes they are blanks made for special aspect ratio applications or very extreme keystoning, (aka pinhole) if they are oval they are telecine blanks for television film chain setups, if they are 1.37:1 with very round corners they are early kinescope ratio aperture plates for television. they would resemble shape of early picture tubes.

[Mark Gulbrandsen]

Short story... I once had a B&L scope lens that was so sharp and contrasty thaat I was able to fool the then President of Schneider that it was actually his lens. Then I switched to the Schneider MC-2X whgich was brand new, and he said get rid of that lens. Then I yelled out the booth port for him to come upstairs and check out this lens..... That let Schneider on a fast chase to figure out why the lenses looked great in the factory, but were way off by the time they got here. Anyway, they actually solved it. The problem was caused by the lens halves twisting from fas release of internal air pressure. I guess they added a few vent holes ubder the astigmatism adjust ring and that solved the problem.

[Stefan Scholz]

Mark, Schneiders were never the big deal in anamorphosers. They were easily superseeded by many others. You are right, the only censorship free anamorphic lens is the 6 element Blue Star, but they were rather rar.
Whereas Schneider ES was bulk in multiplex installations in many countries, and should be easy to find and grab, even though it's some years too late, as the d-cinema conversion worldwide is through.
They are adjustable down to 5 feet, and do an ok image, way better, than the 3 or 4 element Kowa from the past. These could work okish on long projection distances, from 60 ft on.

[Steve Pike]

Hi All

Just thought I’d give an update - thanks to everyone’s advice again.

I have been able to get hold of a Schneider anamorphic lens, which had a backing lens with a focal of 67.5mm. I then found a lens on eBay for 65mm focal length and this filled the screen nicely . And have also been able to adjust the astigmatism on the anamorphic and so now it’s nice and clear.

Photos attached don’t really show the clearness too well and I took the photo whilst Luke and Leia were in mid swing so it actually looks pretty bad … but I can tell you it’s a major improvement on before!. By the way, the photo is of the Star Wars 1997 reissue trailer. Not the film. That’s on a wish list when I win the lottery!

Anyway, thanks all again for the tips and pointers. Have a great Christmas

[Sascha Roll]

Now you can work to improve your illumination uniformity for a nice evenly lit image
Improving never stops.