Well, yeah, if you use a cutted groud glass, made of glass and not plastic, you will have more quality, and you will loose less light steps.

Also, the ideal place for me for the motor is in the center of the spindle, it even have te same diameter to fit those very popular chinese motor toys.

I love all that about calling this adaptor the Agus35 ... heheheh

Posted by Brandt<<The ground glass essentially is acting as a rear-projection element and is re-establishing your depth of focus by reimaging what you are seeing through the 35mm lens.>>

I understand all that. I just can't picture why the light isn't at that same place, plane or distance if you focus on it. I guess the light must actually strike something to be seen.

I see how there are advantages to using mirrors, prism, etc. so as to be looking at the other side of the frosted glass and not having to look through it. That has to really cut down the light as has been discussed. Plus looking at other side it's possible to flip the image. Good bit more involved to make though.

Ok, this is quite simple, it seens that you havent even tried up the adapter, and also you seen not to understand how it works.

The adapter is way to simple to use, to build and the picture quality is amazing clear and pefect DOF... now, if you want to build another adapter using no ground glass and mirros... well... i think that is another topic.

The challenge was to build an adapter which would cost less than 10 dollars, and you could get equal image to the mini 35... i have succeded, the image is clear, i have DOF control, no vigneting... no noise...

the mini35 offers many more really advanced features, but i have adchieved the simpliest ones and the most important.

You need the ground glass.. i dont know why you are putting that you can do it, when you havent even tried. When i look at the mini 35, ithought it was just as simple to put the SLR lens in front of the DV camera, NO... it doest work that way...

So, pick up an SLR camera lens, your dv camera, and tried like you said, to use mirros, and no ground glass, the point is that this topic is about this adapter, which was built only using a 25 cd spindle, and cheap toy with an electric engine...

no means to offend, just to continue moving forward with this project.

another test...

http://altoque.tv/35mmAdapter/kartfilm.mov

about the GG, i wonder about its weight... cause if it is too heavy it will force a lot the little engine.

I guess the light must actually strike something to be seen.

Exactly. Without actually being projected onto the ground glass, you'll just be bending the light more, which will affect the DOF as if the camera was taking the picture itself. With the ground glass, it's more like your camera is taking a picture of a photograph, or of, say, a movie screen. The picture of the photo or movie screen will show the shallow DOF that the movie camera did. Your camera isn't actually getting real light that's passing through the 35mm lens, it's taking a picture of the image it's projecting, which is a completely different thing.

That's why you can get a shallow DOF on your DV camera using this even if you're zoomed in, with a small aperture, and your CCD is only 1/3"... the usual rules don't apply since you're taking a picture of a picture, not of actual things.

By the way, Agus... what sort of processing are you doing on that footage? It looks very dark, what are the settings you're using? And maybe it's just me, but I'm seeing a little vignetting on the edges... did you not zoom in like you said you were before? All in all though, that looks really good.

I was also just thinking that in a later version of "Angus35" it would be possible with maybe the use of mirrors to vertically flip the image before it got recorded onto the camera to take away from the hassle.

Jon Yurek,
Thank you. That answers my question. I guess the angle of the light changes when it hits the frosted glass.

Agus,
I do understand how it works. I have been looking into this for almost 2 years. I have not tried it yet because I lost everything to a fire some months ago before I could start. I never said that you could get away without the frosted glass only asking if you had tried and what you got. Jon's answer explains why that wouldn't work. You have the DOF and no grain but it also looks dark especially around the edges. Sorry if I got off topic but thought this thread might lead someone on another quest like earlier threads led you to this one.

Noah Posnick,
Stay tuned I am sure you will see other versions.

why are you still calling me angus ? it is Agus.. from Agustin , .. hehehe

Yeah. my comercial version will use a pentaprism to correct the image. but that will take long until it will be avaible, now you can try up the free version :)

About the vigenting Jon, in some scenes i use it as visual effect, :-) i dont see it very dark, could it be that maybe your screen brightness is too low ? (i have to admit, that while i was shooting, the adaptor move a little to the right, check the other side there is no vigneting, after a stupid kid came running and made my camera fall !!!!, that also scracted and bump my 50mm lens... damn, but i can ensure you that there is no vigneting when it is centered, i just didnt noticed.)


I tried to copy a mini35 demo video, which use motocross racers, this is not motocross actually, but you will get the idea, i use Magic bullet, and look suite, and RE smoothkit (to take out the staicases from the interlacing... my cheap TRV18 needs some help always)...

Chek the part where the guy fall, you will see that the other bikes coming in front are really blurred, and also the behind the crash the same happens, your attetion will be only with him, that is the real DOF meaning.

Hey Agus,

I have a few questions (trying to build my own now! And I have a Sony TRV17! :-)

1. How exactly did you affix the end of the motor to the spinning CD? It seems difficult to center/stick to the CD... what did you use to do this?

2. What toy did you get the motor out of? Was it a dreamcast controller, coz if so, I have one of those lying around myself :-)

thanks!! I will take pictures of my Agus35 as well once I get it going...

paulb

hehehe you got the my little sister camera of my own.. the TRV18 and 17 are almost the same...

ok.. dont laugh, but i took a lego toy, and remove one pice that was the wheel, put it into another bigger lego piece (they are great, cause they are 100% centered) , and then make the cd to fit to that piece...

the toy was a Xmas ball that start throwing some fake snow... from there i took the switch and the batery holder as well.

let me post some pictures of it, so you can understand it more.

Some high quality images

http://altoque.tv/35mmAdapter/moto01.jpg
http://altoque.tv/35mmAdapter/moto02.jpg
http://altoque.tv/35mmAdapter/moto03.jpg
http://altoque.tv/35mmAdapter/moto04.jpg
http://altoque.tv/35mmAdapter/moto05.jpg

Here is a cool video !!!

Quicktime
http://altoque.tv/35mmAdapter/moto35mmfilmtest2v4.mov

Windows Media
http://altoque.tv/35mmAdapter/moto35mmfilmtest2v4.wmv

This could be a good source for the projection glass.

http://www.edmundoptics.com/IOD/Browse.cfm?catid=453

These guys make all sorts of good optic supplies.

Hi Agus!

Well, I finished building the first version of my Agus35 tonight... Unfortunately for some reason my computer won't see the camera as a DV deck so I can't import footage at the moment, but I will as soon as I get it working... In the meantime:

I can't seem to get rid of vignetting. I am using a TRV17, and at the closest I can place the lens to the ground glass, I still get a bright spot in the middle of the image (much like your earlier footage Agus.) If I zoom in more than about half way, it goes wildly out of focus. I think I may need to use a magnifying glass as you did in your device but Im not sure where to find that... Also, where exactly it is mounted in the device?

My problem is that I basically can't zoom in enough to cover the entire screen with the bright spot.

thanks for any help! Almost there!

paulb

p.s. I used the spindle from a broken CD player I had lying around as the motor/ground-glass axle. It works beautifully because it mounts the CD perfectly centered on the attached little plastic mount disc with ZERO vibration! A cd player with this type of motor/mount could be found at toysrus/bestbuy/whatever for less than 20 dollars.

Paul,

Were you able to use the CD player motor too? That is a brilliant idea...remove a cheap CD player's inards, replace them to a housing, and all you have to do is get the distance right on how far the "glass" is from the lens and hit "play"!!! I wonder if you can remove the CD laser(?) and still be able to hit play and it would work, then hit stop when done???? What'd you think?

Clay

P.S. Then you could also run it on two AA batteries!!!

I skipped using any of the rest of the CD player's electronics for now. My main goal in canabalizing the player was to get at the little plastic piece that the CD sits on, because this is perfectly centered on the motor and gives zero vibration (it's built to do that!)

paulb

Okay, I now have a quote for a manufactured piece of ground glass:

100mm diameter with a 10mm hole in the centre is £70 ($121 at the current exchange rate) for a one off. But bear in mind that industrial optics manufacturers tend to do bulk orders rather than one off commissions. Also I'm not sure what the thickness is, but if it's similar to edmund optics then it should only be 1mm, so it shouldn't add too much weight on the motor..

I think I'll stick with the plastic cd until one of you sees how much better the adapter performs with "proper" ground glass. After all the XL1s might cope fine with the loss of stops..

Anyway I'm getting a little ahead of myself, as my first problem's going to be getting the adapter on to the XL1s in the first place :o)

Kieran

One other thing... I've been looking into ground glass, and it doesn't look like it's too difficult to make your own. You basically take two sheets of glass, and rub them together for 15 minutes with a very fine grit and some water inbetween (apparently Bearing grit will do the trick, from an auto store). From there, you can cut the pane of glass into a circle with a circular glass cutter. Most of that stuff can be found in a stained glass art supply store, such as Hobby Lobby.

The only trick will be the fact that I can't cut a CD-sized hole small enough in the middle, coz the circular glass cutter won't go that small. Instead, what I think im going to do is cut a larger hole, and then affix the CD to the surface of the glass with glue, therefore giving me a CD sized hole :-)

paulb

yeah.. that is a excellente solution, but remember to take a close look to the weight, you cant force the little motor too much to get high spining speeds

I've been following this thread for a couple of days now-and I'm getting excited! I operate in EXTREME low budget filming and this cheap of a 35 mm solution (as far as DOF goes) looks promising. However, I am still quite naive in this field-and have a couple of questions...


-There has not been any detailed tutorial posted yet on the construction of this homemade adapter, correct? When I get some time I might get building from the info from the previous posts-but I just wanted to make sure I hadn't skipped the completed tutorial.

-I have been saving for a Canon XL1s, but am a little fuzzy on the easiest way to adapt a 35mm lens to it. The interchangeable lens feature of the XL1s attracted me-is there not a way to take a Canon 35 mm lens and stick it onto the XL1s? Or is this still relatively expensive or just not a part of the interchangeable lens design. Has anyone successfully adapted Agus's setup to the XL1s?

- For my final question I demonstrate my complete ignorance. I know little about different camera lenses-especially in price. About how much is a decent 35mm lens that could be used on this setup? Other than this (and the camera) the rest of the material could be purchased for under $10-&15, correct?

A big thank-you to all who have spent their time in posting examples, asking questions, and designing the adapter in the first place! You're inspiring.

The XL1 is going to be the most difficult camera to adapt to the Agus35. You need a lens to focus the image from the ground glass onto the CCD's. In the mini35, for the DVX100 and the PD150, they use the camera's built-in lens (as Agus is using for his adapter). For the XL1 mini35, they supply a relay lens for that purpose. If you have an XL1 and don't have a relay lens, you won't be able to use the Agus35 (unless you want to stick it on the front of your 16x lens).

Today we shoot a Maseratti racing car, i got some awesome shoots that i will post later...

Jacob, you can adapt 35mm lens to the xls, but you wont get DOF, but you can find some canon SLR lens (could be old) that are used to get pictures to really close distance, in that way you can shoot the ground glass with no problem... so in other words you need to find a relay lens that replace your 16x one to a macro type one (dunno if macro is used to take close pictures).

I have tons of work i am sorry for no posting the plans yet, but i really barely have time to sleep.

I have a pd150 camera

I need to magnify the image as I can't focus on it and its too small when its in focus...

I can't afford to break any of my wide angle lens as agus did.

Can I by a macro or "telephoto" lens that will do the same thing? or amy i thinking wrongly?

I actually believe the XL1S is perfectly suited for the Agus35. There may be some other costs involved but very nominal comparison to purchasing/leasing the Mini35. So far these are my plans, the most important part is the support bracket, which I have just ordered this, a baseplate with rails $295(http://www.jbkcine.com/i-1.JPG) from here http://www.jbkcine.com, I also have an EF adapter, but you can probably pick one up here $395, http://www.virtualcybervision.com/xl1/EOSMAIN.htm (btw, all EF adapaters are real pieces of junk, they don't really work unless you have, like, a 500mm lens) but since they are machined one offs, you might be able to pick one up on ebay a bit cheaper. Now once you have the adapter, you can put on a standard prime lens, hopefully, I'll know when my brackett and rods come in, I should just about be able to stand a 25CD container right on top + batteries, and the lens on the other side. Since the camera already large I think good support base is important. As far as the glass, I've working with a stain glass person to help me cut different types of glass I want to test out. Very cheap actually, $5 per glass cut in the shape of a CD. I'll either dremel one side to make a gg (ground glass) or get them to use etching acid (which i think could be best) and also, just for experiementing I ordered 2 - 5 x7 sheets of optic quality gg like $30 bucks total... so that's where i am at so far with my Agus35, I'll keep everyone posted, stay tuned....

ps: also why the xl1 is great is because of it's AMAZING low light capabilities, once you have an ideal optical adjustment the results should be stunning...

Hey everyone, after tracking this thread with bated breath and waiting for our good buddy Agus to release a "how-to," I couldn't take it anymore and finally went out yesterday and made my own "Agus 50mm mod." Based on the "Ghetto 35mm" (which is a sweet name, Jun) and Agus' pics I went around town and collected:

- 30 cd-r pack (for the spindle and clear cd)
- 3V electric motor + AAA housing (gotta love Radioshack)
- A rear lens cap for my Dad's old Olympus 50mm lens
- Some black paint from Wal-Mart for a buck
- Already had sand paper, a glue gun, and the lens

Hard to believe that's all you need, but sho'nuff it is. First I took the rear lens cap and sawed off the back (a laborious job indeed for a young squire with only a hacksaw) but I managed. The reason I used this to connect the 50mm lens to the body was so that you could easily interchange lenses and avoid gluing the whole lens to the body (pops wasn't too keen on that one, see the pic below). Then with a bit of elbow grease I cut the 50mm hole in the top cover of the cd-r spindle, then the 58mm hole in the back (for my GL1's lens).

It was then that I realized that our 58mm cams (VX2K, GL1, GL2, PD-150) require a hole that covers part of the middle of the back - exactly where the motor needed to sit. So, I opted to install the motor from the front. (more cutting in the front part of the cd-r spindle) I next took some very fine sandpaper and scratched away at the plastic cd. I broke an old, soft, plastic cd case and mounted just the center part to the shaft of the motor, then popped the cd on. (You can barely see it in the pic labeled "guts". This way it's pretty much centered with little vibration that Agus experienced.

After that - I got out the hot glue gun and went to town. I adhered the now back-less back lens cap around my 50mm hole, and stuck the motor in and glued it securely directly beneath my lens mount. Hot glue is about the best thing for this because it's strong, but can easily be broken away if you mess up. I found it helpful. Of course, before I glued the motor in place I put the lens on the back lens cap mount I made and checked which focal length resulted in a sharp image on the scratched cd. Then I glued the motor with the cd on. Next I simply painted the whole thing and allowed it to dry overnight.

It works like a charm on my naked eye, unfortunately, my GL1 is in the shop due to a faulty LCD (crocodile tears) Therefore I don't have any video to share. I took the pics below so you can see the finished product. The pics of it in action are pretty sheissty, not too much I can do with a digi-cam, and they really don't do justice to what you see with your eye alone.

I attached it to my parent's old VHS-C cam and it works pretty well (as well as it can work with such a consumer cam) but it's really quite amazing how the image is projected onto the spinning plastic. Anyways, hope I didn't babble too much, and I wanna send thanks out to Agus, Jun, and everyone else on the thread for contributing ideas! I hope this post can help someone out!

http://www.par-t-com.net/50mm_wide.JPG
http://www.par-t-com.net/50mm_lens.JPG
http://www.par-t-com.net/50mm_guts.JPG
http://www.par-t-com.net/50mm_far.JPG
http://www.par-t-com.net/50mm_close.JPG

Good job Devin, now you are the third owner know to have a Agus35 built (i love the name... why would be ??)

Have a question, how exactly did you made that part where you attach your lens ? i looks like it has a lock in system.

Again, congratulations, and i would suggest you to use a 600 sandpapers for the cd, and make little scracthes, as you will noticed then with the camera you will get a better stable image if you make the GG with it.

Also, for everybody, let me recomend to shut down the steady shot, it wont work with Agus35 and again you will get a better image, also put the auto shutter to off and set it manually.

Looks good, could you give me the model number of the motor parts, as I'll be making my trip to radio shack soon. One quick question: it doesn't seem that you have a way to make sure the connection between your 35mm adapter and the GL1 is secure. In other words, what's preventing the adapter from falling off the GL1 when your lets say in the process of a tilt?

Agus - Thanks! The part where the lens connects to the body is merely a back lens cap for an olympus lens, the only thing I did was saw off the back so that way it became a ring. It does lock, but not enough that I'd be comfortable shaking the system around a lot. It was 3 bucks at my local camera shop. Once again, kudos for coming up with the cd spindle idea and starting this thread!

Noah - It's just a 1.5V-3V motor. At radioshack they should have a drawer of them. They have larger motors, but i figured this would do the trick and is small enough. It's powered by 2 AAA's. About connecting it to my camera - there's nothing preventing it from coming off. Since my cam is at Canon's repair factory I have no way of working on that facet of the adapter - yet. So try some things on your own, it shouldn't be too tough!

Is there too much motor noise ? i am having serious issues about audio in my agus 35, seens like i will have to put it inside, or look for a way to make it silent.

It's not completely silent, but then again it's not terribly loud either. There's no way you could use onboard audio with it running though. Where is your motor located? I never saw it in the pics.

Hi everyone,
I stumbled onto this topic about a week ago and I've been very interested in trying to make one of the Agus 35 adapters. About a year ago I did alot of research into the P&S Technik adapters but it was out of my price range, however I love the shallow DOF 35 mm lenses give the image. I decided to give the Agus35 a try. Here is my experience so far.

The camera I am using is the Sony VX-1000. I figured that the 2 big problems I would encounter would be how to attach and center the motor to the spindle base and how to attach the cd to the motor..

I purchased the motor at Radio Shack for a couple dollars. It runs off of 2 AAA batteries. I also bought a small on/off switch. Underneath the spindle base I used thin wood so I could mount the motor to something rigid using 2 machine screws that screw into the bottom plastic of the motor.

Next, with the motor secure I soldered the wires to the on/off switch and batteries and centered the plastic spindle bottom to the wood using 4 wood screws. This basically serves as a fastener for the 3 tabs on the bottom of the spindle housing which holds the housing secure.

Next using a hole saw drill bit I drilled a 72mm hole through the bottom of the plastic and wood to accept the lense of my VX-1000. I'm planning on attaching a 72mm filter ring to the outside of the hole to make fastening the camera easier.

I then attached the the cd which I sanded using 400 grit sandpaper bought from Home Depot. To center the cd on the motor I used parts from an old cd burner that I took apart. I then taped the piece of hardware in the center of the sanded cd. The hole in this hardware accepted the motor shaft and the cd centered perfectly.
Next I drilled a hole in the top of the spindle housing to attach the 35mm lense, covered it with black duck tape to block the light and assembled the base,sanded cd, top housing,35mm lense and vx-1000 together.
With all the pieces assembled to my amazment I saw the upside down image in the spinning cd with all the elements of shallow DOF. When the cd spins the image begins to take on a hologram effect. All thats left to do is capture the image with my camera.

A couple things I noticed: A 25 pack spindle did not work for me because the spinning cd was to close to the 35mm lense to give me a usable image so I had to go with a 50 pack. This gave me just about the right distance to see the image in the cd properly. And also I had to use my set of close up macro filters in order to be able to zoom in and still be able to focus my VX-1000 on the image on the spinning cd.
The images seem to be very dark. Is this normal?

Its still a work in progress. I'm gonna post some pictures of my device soon as I figure out how to post jpeg files to this board. Sorry for the long post
Bye for now
Thanks ,
Mike

You posted right before I was going to point out, that I cannibalized an old CDROM. (note: even though it was only a 12x, it worked, and I felt strange pangs of guilt taking it apart...I think I paid $60 for the thing originally)

Anyway, in the middle of the guts, is the spindle that "captures" the CDrom when the tray slides in. (it's really rather ingenious how these things are built). The spindle is mounted so it slides into place in the cdrom's center hole as the tray shuts. After removing the spindle, there was another piece, a round plate, that is built into the cdrom housing, that is magnetized. When a CDrom is on the spindle, the little suciton-cup shaped thingy sticks to it and holds it on.

As Mike mentioned, the radio shack motors fit onto the spindles rather easily.

BTW...the one part of this process that I lack is an SLR lens. I've seen several used ones for sale fairly cheap. What sort of focal length should I get. I've seen variance from 25mm through 200mm.

Jeremiah

jeremiah, start with a 50mm, that is the standard size... basically it will mimic close to your natural eyes perspective of vision.

Zac

I just finished my 'Agus35'. I found an old Sony Walkman, used the motor, epoxying it to the blank CD. there seems to be virtually no vibration. Also used a lens adapter, which I epoxied to the rear of the CD case for attachment to the camcorder. The sanded CD captures the image perfectly! My camcorder - a Panasonic PV-DV-400.

Next upgrade: ground glass.

Thanks to all for this great project and extremely helpful information.

<<<-- Originally posted by Noah Posnick : Could anyone please give some recomendations for a "macro filter" for the Canon GL1 that will allow me to keep the camera focused while zoomed in at a short distance. -->>>

Century Optics makes 2x, 4x and 7x macro adapters. They do not come cheap, though -- $210 from B&H.

I'm making an Agus35 Pro for my GL-1 without a macro adapter. I'll let you know if/how I get it to work.

- jim

<<<-- Originally posted by Yang Wen : What is the concept here?-->>>

The concept is that you use your DV camera to record a 35mm image suspended on a semi-permeable screen.

That's it.

How you get that done best is up to you, though Agus's method is a good one - use a clear disc that is sanded to a 'frosted' surface and spin it through the beam of light passing through a 35mm lens. The disc suspends the image in mid-air, for your miniDV camera to focus on. You set the focus on your DV camera manually, and use the 35mm lens to pull focus with.

Some thoughts:

People seem to be thinking of ways to upright the image and confining their answers to the adapter. Why not use mirrors mounted via a hood on the LCD screen to upright the image?

You could sand the disc irregularly, leaving gaps that are entirely clear, or place black tape on the disc, too. With this you might get some interesting strobe effects, like the lower shutter speeds on the Sony cams.

The disc could be multi-colored, or you could use multiple discs of different colors instead of filters.

- jim

My minolta lens are 50mm 1:2 and i get no vigneting.

So this clear disk has to be in a light proof casing correct? Otherwise, the outside light would bleach out the projected image from the SLR lens. Correct? and how far should this spinning disk be from your Camcorder lens? is it dependent on the camcorder lens and better done with a trial and error strategy?

check out this lens, you can also have zoom, and it have a good aperture size.

http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=61424&is=REG

Ok I grabbed a fake CD thing from my spindle and got my Sigma 35-135 AF zoom lens and just held the two things up in front of my DVX100. I had the DVX's lense focus into macro-mode and the CD was in focus but As you can see, there is incredible vignetting. It seems I can only get a small round image to project. What is the trick of having the 35mm lens image fill the entire frame?

http://www.umich.edu/~ywenz/DVX/GhettoAttempt.wmv

thanks

<<<-- Originally posted by Yang Wen : Ok I grabbed a fake CD thing from my spindle and got my Sigma 35-135 AF zoom lens and just held the two things up in front of my DVX100. I had the DVX's lense focus into macro-mode and the CD was in focus but As you can see, there is incredible vignetting. It seems I can only get a small round image to project. What is the trick of having the 35mm lens image fill the entire frame?

http://www.umich.edu/~ywenz/DVX/GhettoAttempt.wmv

thanks -->>>

Hey, why you call it Ghetto ?? it should be Agus35 :)

Ok, you got several problems... first, you need to use the whole spindle plastic case, cause that will not permit the light from outside to ruin the image in the ground glass... then... you need to adapt a Magnifying glass to the dv camera, so in that way you will get more of the image projected, then you need to close as much as you can the GG to the camera lens...

http://altoque.tv/maserati.wmv

Take a look to the second 20 of the video, and the last scene, and there is no vigneting

Check it out, it doesnt have too much quality but i really dont have any time, working a lot with a 3d spot.


Mike,
you can email them to me also...

check my profile for my email.

Agus, that's the best footage yet. It really looks like film, especially the last shot. This thing will be amazingly useful for making short films.. I mean there are big problems trying to follow a car as it speeds round a track (good work on that by the way) but in a scene that you've planned out it'll be fine..

Yang, you need to understand how the adapter works. Your DV camera is effectively being used as some sort of telecine unit - its only purpose is to capture the image created by the 35mm lens. It's like ghetto telecine - videoing your film footage as you project it against a wall. That means the only thing you need to be able to do with your video camera is zoom and focus until the image fills the screen. Also take the camera completely out of auto mode, so there's no gain, no focus problems, and a standard shutter speed.

Next you need to understand what's going on with the lens and the housing and the spinning cd. The housing stops any light getting in. Just like an ordinary stills camera - the only light you want coming in is the light that comes in through the lens. The role of the the sand-papered CD is to act as a projection screen. It's like the film in a stills camera - it's where the image from the lens is focused. The reason it needs to spin is so that you get rid of the grain caused by sanding the cd.

So what you're doing is using the 35mm lens to create the image - to zoom, to set the exposure, etc. And you're using the video camera to capture this image.

By the way Agus, have you experienced the "spinning vortex" that mini35 users refer to?

Kieran

You can email photos to me and I'll put 'em up here at dvinfo.net -- here are Richard Mellor's images:

http://www.dvinfo.net/media/rmtopview.jpg
http://www.dvinfo.net/media/rmsonywalkman.jpg
http://www.dvinfo.net/media/rmlensadapter.jpg
http://www.dvinfo.net/media/rmcdepoxied.jpg
http://www.dvinfo.net/media/rmrearview.jpg
http://www.dvinfo.net/media/rmcloseupmotor.jpg

From Mike Perkin:

http://www.dvinfo.net/media/mpsandedcd.jpg
http://www.dvinfo.net/media/mpmotorwithcd.jpg
http://www.dvinfo.net/media/mpmotoronbase.jpg
http://www.dvinfo.net/media/mpmotorandcd.jpg
http://www.dvinfo.net/media/mpinsideprojection.jpg
http://www.dvinfo.net/media/mpfronthousing.jpg

Concept - As I understand it.

Stage One

Subject being videod/filmed >>> via SLR camera lens >>> onto a semi-opaque screen (like a rear projection TV screen) positioned on the lens focal plane --- the same position the film would be if if the SLR lens was mounted to a camera. (This is a focal plane for that lens.)

Stage Two

That image (like a projected image) on the semi-opaque screen >>> via video camcorder lens >>> onto 1 x CCD chip or (3 x CCD chip array) To get that image to appear large enough to fill your video camcorder viewfinder, you may have to use a close-up lens or if that is not powerful enough, make up a relay lens to get the camcorder to focus on the projected image sharply enough.

The relay lens might be something like the eyepiece out of a telescope. I have used a lens set out of a 42mm telescope eyepiece and placed that between the camcorder lens and the projected image for another similar application.

SUMMARY: There are two stages of focussing. The SLR lens focussing sharp onto the semi-opaque screen. The camcorder aquiring a sharp image of that projected image. You are taking a picture of a picture. This is not realy the most efficient way of aquiring an image but ---

from this point is where it gets interesting. You just can't get a frosted glass texture fine enough to display the image from the SLR lens sharply enough. If the texture is too fine, then you can see through the glass beyond the focal plane into the guts of the SLR lens and through that all the way to your subject. So all you see is a bright hole. If the frosted glass texture is too course, then all you see is a pattern of rough pits and scratches colored vaguely in the form of the image.

If you try to look through a raindrop blinded windscreen on your car or the wire mesh on a screen door, you discover that if you move your head about, you can see through the obstruction. P&S Tecknik, cleverly worked this principle by moving the windscreen instead of the viewpoint.

You are not looking at your subject through the groudnglass screen with the Mini35 adaptor, you are looking at an image projected onto the groundglass screen which is made to seem finer by being moved faster than the camera can see its rough texture. The Mini35 adaptor moves this screen by spinning it across the SLR lens focal plane. Agus' earlier prototype as I understand it rapidly moved a screen back and forth across the SLR lens focal plane.

The Mini35 operating notes tell you that you must keep your camcorder shutter speed selected slow so that you do not freeze the motion of the rotating screen and thus detect the frosted texture on it and spoil the image.

I hope this has not confused you too much.

That's a very good description indeed.

I'm still not sure if a relay lens is strictly needed. With the original mini35 and the XL1s it was simply more practical to take advantage of the fact that you could remove the XL1s' stock lens - it makes everything less bulky. The only problem with optics for the Agus35 is being able to 1) focus the image 2) zoom until it fills the screen, which, as people are discovering, can be difficult to do simultaneously.

I'm thinking about using some kind of sliding close up filter between the XL1s lens and the cd so I can experiment a bit with zoom and focus.

Only a week till I start work on it :o)

Kieran

About connecting it to our cameras - this has become a major concern between my video compadre Spencer Houck and I. We're both concerned about the best way to secure this beast to our cameras. I noticed someone had a 58mm thread glued into the back of the spindle - I had that same idea, but since this thing is a little front heavy methinks it'll put a lot of strain on the threads. It might not be such a idea to secure it that way and warp the threads, after all, I really do like the ability to switch adapters and filters!

We were thinking more along the lines of a bayonet mount (for those of us that have lens hoods). We tried looking for a place that sells the lens hood alone for the GL1/VX2K, but alas, no dice. I think it's an important issuse, I'd like to hear what others have to say - esp. those that don't have a bayonet mount. How do you do it Agus?

I used WMV 9 to encode the footage, if you do'nt ahve Media Player 9, you can't view it. Sorry.

On the mount... I guess you can also constructut a plate that attaches to the Agus35, that your camera screws into. That way, the weight is not on the mounting threads to hold the entire assembly up. It'd be a big unit all together, but it would give you more weight and would resemble a film camera even more!

Wow i suspect if I can get a 3D model of this Agus35 caseing made, I can use the prototype machine at my school and get a 3D copy of it printed. Then somewhere on campus I can get copies of this thing made. Perhaps get a two piece design that screws togeether, compelete with the holes to accept adapter rings?

here are two images...

http://www.orfilms.com/35test.jpg

http://www.orfilms.com/35test2.jpg

<<<-- Originally posted by Devin Doyle :
We were thinking more along the lines of a bayonet mount (for those of us that have lens hoods). We tried looking for a place that sells the lens hood alone for the GL1/VX2K, but alas, no dice. I think it's an important issuse, I'd like to hear what others have to say - esp. those that don't have a bayonet mount. How do you do it Agus? -->>>

I use a metal piece that connects to the tripod hole in the camera, so the whole piece is more stable