Early on I thought I about using bellows but figured they couldnt handle the weight of some of the large zooms (particularly PL mount cine zooms). And perhaps Im being picky but it would give the adapter a old fashion look that I wasnt going for.

-B

I dismantled several zoom lens for that purpose and answer is yes, it is possible but there is an heavy way of cutting the 24x36 window into the moving part, as this one usually is smaller..
the mechanic is infact just 3 bars acting as guides, with two plates (front and rear) moved by a small cursor driven by the slot of the main cylinder.
that is for tele zoom system, range is very big.
for a smaller fixed lens, the mechanic is simpler and range should be better (smaller)
A variable system is good in fact for a prototype, but for the final one, if you got all the correct distance, there would be no need to have this.
you can screw together 2 filters mount , one with the lens or glass and one empty, and you got 2 or 3 turns on the screw to have a bit of adjusting available.

Actually if you plan on using more than one type of lens (Nikon, Canon, PL mount) they all require different focal lengths. The difference between one lens maker and another might be the difference of one or two threads while others are much more dramatic. Check the flange focal length chart to see what you need.

Bottom line you DO need a adjustable adapter if your going to use both Cine and Still lenses.

-Brett Erskine

i think for those who go the full fledge device, they should choose for a short distance from the gg to a T-mount and then use t-mount converter to their lens mount (10$ at http://surplusshed.com/) so they can modify the adapter to get the proper distance.
edmund optics has such t-mount ring you can assemble to have the distance needed http://www.edmundoptics.com/IOD/DisplayProduct.cfm?productid=1382
and t mount tubes
http://www.edmundoptics.com/IOD/DisplayProduct.cfm?productid=1285
My opinion is that moving the lens (that is a removable stuff anyway) is more convenient than having a movable gg
K.I.S

actually if you plan a simple kit assembly minidv35 by just screwing together already made element, the T-mount 42mm format is very good. you will find lens or lens adapter, tubes, filter (for the glass) and many lens are around this size.
Edmund optics as a very complete offenring into T-mount parts, but it will push the budget envellope a bit higher and it worth it since you couldget your minidv35 ready in only few hours.

anyway at http://surplusshed.com/ you will really find for cheap everything you can dream for your homemade minidv35.
From the single lens to a full tele zoom for parts.
and some cheap t-mount lense here
http://www.colescameras.com/tmount.htm
in a surplus shop i got on saturday a old but never used TTL camera
(brand PETRI) with a 50mm and 135 lens for 40$.
it is almost a shame to break it, it looks so good, but it has a nice T-mount ring fixed on the body with 3 screws that would be perfect on my prototype.
I will try to find another t-mount support, if i can

I just get a question about lenses.
for the same type of lens (50mm for example) you got different "f" value.
I suppose this reflects the aperture of the lens.
What i do not know is if there is a difference between a high end lens that give lot of light and a cheap one that probably has few "f" more. Probably it matters when using films but what about using a CCD.
Is there an equivalence between a CCD(lux sensitivity ) and ASA ?

Alain:

I followed the ground glass tutorial circulating and it seems to work just fine. It could probably work either way, though I found grinding the filter, versus grinding the glass with the filter, to have more swift results.

John: I "need" a condensor? I'll wait and see on that.

- jim

Giroud,
I think the lighting calculations apply equally to both film and video. There is just a difference between the calculations just like a British pound is greater than the US dollar but people in England might earn less gbp in a month than people earn dollars in US. I am very new to this myself but i think the increase in ISO foot candles number means the decrease in the f stop(brighter). Since one third of a stop is the maximum difference a human eye can spot that is the same way ISO numbers increase. Let's say we have two film stocks one is 100fc and the other is 200fc so the difference of going from 100fc stock to 200fc stock in the sensitivity is 1 full stop faster (double the light). I hope i touched your question in some way please correct me if i am wrong which is very possible.

Reverse T-mount
 

Giroud: the $10 adapters at surplus shed are for attaching a T-mount lens to your camera, NOT a t-mount tube to an SLR lens. The latter requires a so-called reverse t-mount adapter which is hard to find. You can custom-order if you're willing to pay extra.

Overall, t-mount is a good solution, but the 42mm diameter won't give you the full 36X24mm image.

Is T-Mount 42 or 48? minimum diameter for 35mm film size is 43.65mm

Yup - 42mm.

http://www.fli-cam.com/FLIsupport/tmount.htm

This article also mentions a 'standard' 2" threaded tube commonly used for telescopes. There are tons of ATM (amateur telescope maker) supply shops which would offer 'standard' items like this, I'd think.

AFAIK, it's 48mm OD / 42mm ID.

in fact the 42mm of a T-mount is ok because the picture on the glass is 36x24 but in between the gg and the lens it is a lot smaller.(just look a the rear lens of a 35mm lens it is very small).
and anyway there is a lot of 35mm sold with this mount so it should work.
So you can solve the mechanical problem of mounting lens on the gg with T-mount but for sure after the GG you will need someting bigger for the condenser and the macro lens.
I thing 52 or 58mm is fine depending your camera.
I think it not worth to spend too much energy on this kind of problem since we can find many relatively cheap way of mounting a 35mm lens over a tube.
the real problem is after the GG ( GG included if you plan to move it) and it is where energy must be put.
to Roman Shafro: yes you are right the t-mount adapter is for mounting T-lens on pentax,nikon etc... but if you are looking for a T-mount support (like me) you will probably need a piece of it (the T-receptaclle).
My opinion is that it is probably better to buy some cheap T-mount lens you can leave on your mini35 than use your expensive nikon lens for weird use.
The advantage of this is you can finish the mini35 and purchase the best lens you need instead fighting with silly mechanical problems.
For sure the ones that are looking for the cheapest price will be reluctant to spend 40 or 100 $ for a lens but regarding the price for the real mini35, i think it the total price stays under 200$ we are still in an interesting situation.
My goal here is to build a mini35 for cheap, with if possible refurbished parts, but in a way that allows a reproduceable build by generating for example a part list with links to provider that allows next people to make their own project.
For instance:
(price including international shipment)
25$ for aluminium grit
5$ for the UV glass filter
15$ for the T-mount adapter
20$ for the condenser lens
20$ for the macro lens
50$ for misc part (from aluminium tube to glue and black paint)
and you got your mini35 for less than 150$.
I think 100$ is not unrealistic.

Giroud:

Where can I get a $20 condensor lens?

Anyone else, for that matter, would you do me the favor of condensing the condensor lens options? :D If I have to pick one up, I'd like to know: what's best, what's cheapest (aside from fresnels, which I don't want), and what's the best compromise between best quality and lowest price?

Thanks,

- jim

Jim, the condenser I am using is from a Petri Aux Telephoto Lens 1:1.9 4.5cm. I took one lens on the telephoto and it's working perfect for me.

Here is something on Ebay , It's not exactly the same as mine.
Petri Auxiliary wide angle and telephoto lenses for 1:2.8 4.5cm

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3801032878&category=29971

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3801141877&category=30077

Alain

Whats up Alain. Whats new with your adapter? What do you think about adjustable still photography extention tubes for our adapters casing.

Hi Brett
 

My adapter is done .I am going to start anoter one whit a lens that I have found this weekend for $30, the optic are not good but the tubing a perfect. This thing's gone a be perfect for what your talking about.

Alain

Is it a internal focus lens? They work the best because the only thing that turns on the lens is the focus ring. May I ask what the make and model is?

-B

just a silly question.
we are looking for achromat lens for the macro one, but do we need a condenser with achromat specs, or this not applies to such kind of lens ?

in need of xl1 aldu examples
 

can i please get some pics, tutorials, footage, of any xl1 with this aldu35? what was the cost to make it? how much would you sell one to me for? sorry for not reading this entire thread to see who is developing one for thier xl1 but, after reading the lengthy aguss35 thread, i decided to jump the gun on this one.

Brett
 

Yes ,It's a Rexatar 200mm .There is some modification to do on this but it's a very good piece to start whit.

Alain

ok
 

after skimming this thread i see that dino reyes is leading the campaigne for the xl1 aldu35. i'm counting on you dino.

Did anyone build an adapter for the DVX100?

finally... the xl1/xl1s version is very close
 

thanks patrick for the encouragement! it's actually great timing, i had a REAL breakthrough this evening. i'm hoping to have something to post by this weekend...

stay tuned
-D

Dino, please keep us informed as soon as possible. I havn't had nearly enough time to read through this thread but if you could sumarize your progress thus far or create a website of some sort to keep track in one central location that would be great.

I've been hoping for a cheap 35 adapter solution to be developed for the XL1s.

I've gotten enought parts to experinment with. I'm having trouble with the tube design. It seems like no matter what I do I cannot get the FFL correct. I'm using pvc parts and am getting a little upset at them. I can get the FFL by hand, just not with the tubes all put together. Does anyone have any suggestions or ideas?

I saw in one post somewhere in all these threads of a threaded tube for R&D build of optics. Now I cannot find it again. Does this ring a bell with anyone?

I took a 10+ macro and put on the camera side of the GG and I don't think a hotspot will be a problem.

If I can get help with this tube I'll be posting pics soon.

Yeah, John -

I'm in a similar boat. I just got my shipment of 'experimental' lenses, with a wide assortment of various plano-convex, achromat, aspheric, and concave lenses to mess with. *plenty* to experiment with, but the mounting/positioning is tough.

I'm using Canon FD lenses, which have a FFL of 42.1mm (really short...), so I have much more trouble with PVC.

Here's what I've done with some success:

I got a male/female pair of the 2" PVC Couplings described in the various tutorials.

The male coupling has a threaded part and then a long 'coupling' part. I put this on the tablesaw and first, cut the coupling way down to about 3mm. This makes a nice 3mm even surface for mounting the canon FD mount.

I have two possible mounts for the Canon lenses: 1 is the actual mounting plate from my disassembled AE-1 - it's about 5mm thick. The other is a 'rear lens cap' like Alain described, with the cap part cut out. It's much thicker at somewhere around 10+mm.

Then I threaded the female part on and tightened it down failry tight. I took a measurement of the distance from the lens with my chosen mount on it, and marked down on the female side of coupling at around 38mm from where the lens actually mates with the mount. With the rear lens mount version, this only leaves me with like 25mm of threads. Still enough to unscrew it the 3-4 mm required for proper focusing.

One trick is to spray paint the male threads. This adds some friction and makes the threading of the loose PVC feel more 'secure'. I haven't done this next part yet, but I've also picked up a tap wrench and a matching die and nylon screw. I'm going to put a threaded hole through the female part of the coupling and thread the nylon screw down there which I can tighten once the adjustment is right. (This idea came from someone else who did it on this board...)

I have also gotten a lot of good utility out of cheap (around $5 at my local camera shop) step-up rings. In my case, the 58mm ring wraps nicely around the end of the 2" pvc and I'm planning to use JB Weld to make a permanent connection here. I'm using a 52mm UV filter as my ground glass, so the 52-58mm step up gives the back end of the coupling a threaded ring to put my ground glass/UV filter (which is threaded) right on to. I think this will be good also because I can just twist the assembly apart for easy cleaning of the ground glass. Of course, the step-up lengthens the FFL and needs to be considered when measuring.

That's as far as I've gotten, but I'm hoping to use a similar contraption in the other direction to get from the threaded ground glass back onto another segment of PVC to attach back to the macro and camcorder (via more step rings).

Made some changes to my tutorial, and added a third page.

The piece of PVC that I'd originally intended to affix the F-mount to ended up being just a hair too short once sawed off, so I purchased another, different piece of coupling and sawed it to a depth of 1 and 1/2 inches.

Initial tests show that grinding both sides of the filter was a mistake :/ Oh well, off to the photo store with $12 in hand...

- jim

Jim's design
 

Jim-
How strong would you say your connections are with your PVC design. Would you be able to suport cine zoom lenses or only 35mm still lenses?

For thoughs painting your threads to make your adapter feel more solid - Dont forget that the paint is likely to start flaking off and creating a mess inside a adapter that must remain absolutely spotless clean inside.

Brett:

If I was going with larger-than-35mm-SLR-lenses, I'd add a support like this:

http://www.bhphotovideo.com/bnh/cont...=126662&is=REG

It's not so much the PVC as it is the achromat that I'd worry about, which bears the brunt of the adapter's weight.

Thanks for your advice re: flaking paint. Shouldn't be too much of a worry provided the paint is sprayed onto a scuffed surface and not laid too heavily. I'm just looking to give it a dampened color on the inside, and a deep black on the out.

Tomorrow I'll probably have mine finished, with more pics. Next week I begin filming a short with it, and I'll have clips up sometime then.

- jim

Brett & Jim, you're both right about painting. There are no good paints for PVC (Crylon for plastics is the only one, but they don't make flat black paint), and regular spraypaints don't stick well, even to sanded surfaces. I used thin coats of some generic ultra-flat paint, and let it dry for about 2 days. It seems to stay on as long as you don't scratch it with something sharp. Still, I only see it as a quick-and-dirty prototype solution.

I just got my bag of lenses from A.S.S. and this condensor REALY made the difference. I will post footage tommorow, It looks as good as Alains.

John Gaspain

I'm going to try coating the inside and outside with this black rubber stuff you dip your tools in. I'm going to thin it and try to be careful in the application.

you got a bag of lenses from ASS, hahaha. Someone had to say it, unfortunately that turned out to be me.

<<<-- Originally posted by John Heskett : I'm going to try coating the inside and outside with this black rubber stuff you dip your tools in. I'm going to thin it and try to be careful in the application. -->>>

If your tube is PVC, Plastic Dye might be be a better solution, its available in a spray can at home depot, its used for lawn chairs 'n stuff.

Or for aluminum tube, anodizing would be the best, which can be done at your local gunsmith.

John Gaspain - condenser lens specs
 

John Gaspain - Let us all know the focal length and diameter of the condenser your using plus the physical length between your condenser and your macro lens.

What about gluing some black velvet or felt inside the tube? My Canon AE-1 was lined with black velvet on the inside...

I also got a shipment of lenses from ASS (chuckle) and yes - the condenser(s) make a huge difference. Additionally - it didn't seem to matter much what I had as a condenser (single-element vs. achromat) as long as my macro was achromatic... seemed to fix any abberations that crept in from the first lens.

Jonathon- Thanks for the info about your condenser. Would you mind answering the questions about FL, diameter, working space.

Velvet will be the best material for soaking up any scattering light BUT your likely to see small pieces of the material come off once in a while and ruin your shots. You have to remember that these adapters are totally unforgiving to even the smallest speck. Our ground glass is in focus and not moving. Anything touching it will also be in focus. Personally Im going to get around this problem by putting standard UV filter between my 35mm lens and the ground glass. The other side of the adapter has the macro len on it so theres no way for dirt to get on or close to the focus plane of the ground glass.

-Brett Erskine

I don't have them in front of me (still at work :-( at 12:30 am, blech). From the limited experimentation I did, It seemed like the focal length of the condenser didn't matter nearly as much as the diameter. The diameter of the condenser absolutely must be larger than the 36x24 (or whatever you plan to captuer) image on the GG.

With the three or so I tried (which all had different FL), I had a large amount of latitude as to where I could position the macro and still get good focus, and nice bright light all the way out with no abberations. I could get out-of-focus images, but I *really* had to move...

This was much much more true with an achromat as a macro. I tried some single-lens elements as Macros and they worked but tons of chroma and spherical distortion.

likely not tonight (will be hitting the sack immediately upon reaching the homefront), but when I get my next free cycle, I'll take some real FL measurements and try to find an 'optimal' position for the macro given those focal lengths and post 'em.

Hear you on the velvet - that makes sense... we definitely need to minimize potential debris in there... Good idea on the additional filter.

Johnathon W - Im REALLY looking forward to thoughs numbers. They will tell everyone alot! When you find out the focal length of each condenser check and write down whats the best distance to have your camera with the macro lens. If you do that for all three there should be a relationship with a noticeable patern (ie. A ratio with the a given distance between condenser and macro lens being X the focal length of the condenser should be Y).

Its good news to hear that its likely we dont have to be extremely picky about the focal length for our condenser for our adapters.

BTW did you ever try doing this setup?:

(l ll l)
<Condenser, Ground Glass, Condenser>

Im curious because thats basically what SLR's have. Instead what we are doing look like this:

ll l)
Ground Glass, Condenser>

Thanks again. Cant wait to hear thoughs numbers.

-Brett Erskine

just a few months ago i heard that there was a "paint" type coating surface invented in england that absorbs about 98% of light that hits it, apparently it makes the surface about 25% more black than traditional matte black paint. If it makes it to the consumer market it'd be perfect for the inside of the adapter.