35mm Adapter Static Aldu35

[Kaushik Shridharani]

<<<-- Originally posted by Richard Mellor :
I have a link to my finished aldu35...

It was made with 52mm lens filters, 1500 grit ground glass, from opto sigma, and a plcx lens


www.dvinfo.net/media/mellor -->>>

Sorry, Richard. I didn't see a jpg for an aldu35. First question I think is if you know the focal length of your PCX lens and how close is it to the length of your 35mm lens.

[Richard Mellor]

kaushik- the first three files ,35mm lens adapter are the aldu35
- need to rename them - the pclx lens is 50mm with a focal
length of 50

[Kaushik Shridharani]

richard -- i wish had the knowledge to do more than take a stab, but i'll take a humble stab:

i take it your pclx is not up against the GG. i would think that having a condenser with approximately the same FL as your 35mm lens also requires it to be as close as possible to the GG. if it's far back from the GG (a 6mm spacer ring is already a hefty 12% of the FL), then its focal point will also be short of the lens "rear principal point" (the imaginary point inside the lens that we want to stay targeted on).

thinking back to the fresnel light analogy, if the light bulb is moved beyond the focal point (ie, the focal point falls short of the source), then it acts like a spot light. this might explain why your peripheral illumination loss has such a hard edge to it (to my eyes).

i guess you have two options: use a pcx lens in the same position but with a slightly longer focal length. or get your current pcx lens right up against the GG.

the other source might be the aperture. if you've got it wide open, light from sources that are off-axis have a greater chance of getting lost compared to light from sources in the center. stop the lens down and you'll get less light overall, but there won't be as much waste of off-axis light sources compared with the center.

[Michael Ogasawara]

I've been busy with school and other things lately, but I've got back on track with my adapter, and I now have a working prototype.
(large image files)
www.edwardflinch.com/images/mini35.htm

I also have a short clip here: (2.6MB)
www.edwardflinch.com/images/testshot.mov

The ground glass is ground with 5 micron grit, and the condenser lenses are from Surplus Shed. All of the components fit together very snugly. I chose the two condenser lens approach after doing some experimenting. I found that it reduced some spherical distortion I was getting.

[Frank Ladner]

Michael: Nice images!

I too am using a GL2 w/ my adapter so I am glad you posted your prototype design for us to check out.

I notice a small amount of grain and maybe some color fringing on the sides, but the frames look good.

By the way, about how much do those PCX lenses run?

Thanks!

[Richard Mellor]

kaushik thank you for your help. I will try the changes.

[Michael Ogasawara]

The PCX lenses are fairly cheap:
http://www.surplusshed.com/pages/item/l2119.html

Now that I have a working assembly, I can do a good comparison between the bosscreen and the ground glass. I will post the results soon.

I also had an idea the other day about an alternative GG. I was reading the thread about microcrystalline wax, and I wondered if some other material could be sandwiched between filters to get that effect. My eyes fell upon a bottle of Elmer's glue, and I grabbed two "junk" 50mm sky filters and proceeded to put a glob between them and squeezed out any bubbles and as much glue as I could. The funny thing is that it works pretty well, with no apperance of grain. I lost several stops, though, but the glue on the outer rim appears to have sealed the glue between the filters to keep it from drying. I will add it to my comparison.

[Pat Worrell]

Nice idea on the glue Michael. I had an idea to use some of that non-reflective frame glass. The two I tried, however, were too transparant to work.

[Les Dit]

Are people using a 35mm movie camera image size on the GG, ( 4 perf 35mm size ) or a full 35mm still image size ( 35mm vista vision, 8 perf ) ?

I think the mini35 product does the movie camera size, but is that what guys using 35mm still lens's actually want?

I see a dilemma here.

-Les

[Rai Orz]

I don´t use a stacic adapter, i use vibration (micro circulation), but 35mm movie frame size or 35mm still image size, that is the same question. If you have original movie camera lenses, you will use movie size. These lenses are very, very expensive and in addition, very bright (mostly 1:1,2 to 1:1,4). If you have the $ for movie lenses, you have it also for use a P+S Adapter. But DOF is not only a question of picture size. Remember: More bright (more open iris) = more DOF. But, more framesize = more DOF too. So if you use a still camera lense with and full size frame, for example 1:2,2 instead of a 1:1,2 lense with movie size, the DOF will the same. The other way is, you can still camera size zoom in, or you can use each size between them, so you can play with different DOF. (But if you zoom, you can see more grid on a STACIC GG and you have a problem with wide angle)

[Les Dit]

Thanks Rai,
I am going to build a micro circulation adapter for my JVC HD10, I don't think a static screen will ever work with my camera.
I think I'll make it big enough for an 8 perf frame.
-Les

[Jesse Rosten]

Looking for some advice...

I'm building a static adapter out of 55mm filter rings. I'm looking for a condenser lens that will fit inside the the 55mm tube I've created. I'm curious to know what you guys think about any of the 50mm lenses listed on the link below. Or do you have another suggestion for where to find a 50-54mm condenser?


http://www.edmundoptics.com/onlineca...=2032&search=1

[Stephen Birdsong]

I've finally finished reading this HUGE thread, and I've started building an adapter for the Xl1s. I heard Dino was building an adapter, but he seems to have disappeared lately. Anyone else trying to figure this thing out for the xl1s? Id love to hear what others have had trouble with and solutions they have found.


I've made some progress, but I have a few problems/questions, maybe someone can give me some suggestions.

1. Condensor lenses:
Im having hot spot problems, and want to add a condensor to my setup to see if that will fix the problem. Where and what to buy? I dont know enough about optics to understand what exactly I need, or even where to get it. At the moment, Im working with 2" pvc pipe and all my filter rings are 52mm. The focal length of my 35mm lens is 50mm. suggestions? links? How are you mounting them on the inside of your adapter? Whatever happened to the idea of putting one on both sides of the gg, has anyone tried that yet?

2. Ground Glass:
At the moment, Im simply using Hollywood frost gel as a substitute ground glass element, as it is much cheaper and faster than actually grinding my own glass, and works pretty decently. although I will be upgrading to reall gg in a later version of my adapter. What is the latest consensus on best option for GG element? I've seen posts about buying ground glass already made, seen about DIY gg, and I've seen posts about alternatives. Whats the latest scoop?

3. Relay lens:
For those of you who own an xl1 or xl1s, you know that its simply not practical to try to add an adapter to the end of the any of the lenses. Their just too long. I currently own a manual 16x and a manual 14x and neither of them will to the job i need it to. So, ive decided to build some sort of relay lense to capture the correctly sized image on the GG (which I havent had much success with yet). I've tried a 1' 16mm motion lens, but it had a very strange effect. I could focus between 1 and 3 inches from the lense (not film plane) but that was it. no more range. even at infinity, it was 3 inches away. So, I was looking at a rectangle (roughly) about 2mm across. definately not big enough, although it was conveniant that it focused so close. I dont know enough about 16mm lenses to keep trying them, so i've decided to try a ultra wide 35mm still lens and see how that would do. The reason i think it would work is because even though it is going to have a major tele effect because of the 7x magnification, its an ultra wide, so I can focus relatively close, and it just might be wide enough to get the 36x24mm image. If anyone has any suggestions, feel free. i really want to get this adapter in a more advanced prototype stage, but im stuck on more than one issue, and dont know where to go.

Stephen Birdsong
by the way, since there are a few threads that have nearly 100 pages of posts, wouldnt it be beneficial to be able to search a single thread, rather than just a category? Who could we recommend that to?

[Rai Orz]

Stephen,
jears ago, i made three kinds of working adapters. One of the camaras it works with, was the Canon L1 / L2. As you know, it is the model before XL1 and had similarly changeable lenses (the only optical diffents are focal length, because: L1/L2 = 1/2" CCD, XL1 = 1/3"CCD). So i think it work also with the XL1. Next week i will test it.
One of my adapters come with static GG (i tested 100s of them, some selfmade all the way are posted here, but no one was satisfyingly) . Finally i found a manufacturer and we developed together a high quality GG (See my posts on Microcrystalline Wax). But unfortunately, another company have a patent on this way. The next two models have moving GG (micro circulation). Moving GG improves the picture always, also if you use the best GG. All modells hase aspheric lenses on both sides of the gg (each with flat side face to the GG). My first and most inexpensive way to focus on the GG with the L1/L2 was that: Apart a old, not working camcorder with smal lenses (with macro) make a connector and took it in place of original Canon lenses.
All my models are supported with a cameraplate, so there is no load on the lenses. (Without this you can destroy your camara body.
Next days, i will post a link to detail informations, with parts, pictures and sources of supply, etc.

[Jim Lafferty]

Has anyone acid-etched their glass successfully?

Based on James Ball's advice, I purchased acid etching cream. I've copied his directions and looked over them carefully, but haven't had the time to set them to use (I'm in the middle of a big move at the moment...)

I'm writing wondering if James or anyone for that matter has had success with his method, or if the lack of updates is evidence of an idea gone wrong?

Thanks,

- jim