I have been working on an Agus 35 and I have a little different design.
I used an old Nikon film camera and took some parts out of it. I noticed that the view finder had a small piece of rectangular frosted glass in it. I used this instead of a sanded spinning cd and found it to be easy to focus on and lets plenty of light in. I have a drawing of what I did if any one is interested. I am experimenting with the picture quality now.
I do not know what this rectangular piece of glass is but it makes a good picture for the video camera to zoom in on and focus.

Video Cam>>UVFilter>>short PVC pipe>>Nikon view finder Rectangular Lenses>>threaded PVC adapter>>short spacer>>Lenses Mounting Plate off old Nikon camera>>Sigma 35mm Lenses

All PVC pipe was 1 ½ in. The Nikon Rectangular Lenses fits into the pvc pipe allowing the Sigma 35mm lenses to focus on it.

HI Agus, i've been following yourpost ever since the start,

Any way about flipping the image

Why not just add optics to the viewfinder you know the camcorders eyepiece and flip that part, that way there no need to turn the camcorder upside down and use any mirrors. OR connect an external LCD monitor (EG pocket TV') and turn that upside down.

I too have been trying to make my own version of MINI35 but using still GG, as spinning GG's take up lots of space.

well there is an optical way to flip the image.

Just use a concave lens, any half decent optometrist can make you one, the only thing is to know the correct size, anyone here know anything about physics and the best place to put the concave glass within the piece?

Zac

I'm currentlyworking on my third version of this adapter... I haven't installed the motor yet, but here is some pics

http://www.orfilms.com/adapter1.jpg

http://www.orfilms.com/adapter2.jpg

Nice implementation, Peter! Really like the box. Is the cat a certified camera operator? Or just an assistant.

A furthur idea on alternative groundglass material between disks, - I tried a small piece of translucent window material which had my new PIN number on it.

This stuff seems to work better than shop bag and might be sourced from a stationer or the manufacturers of the PIN number forms might be able to advise the source.

It may be a commonly available modern plastic based tracing paper. Placing between two clear disks to keep it in alignment might be an option.

I have also asked Chris to post a .jpg of a a relay adaptor for the PD150 I mentioned furthur back in these posts.

It is at http://www.dvinfo.net/media/bhe11.jpg

I have a .tcw design drawing showing lens positions however in making the prototypes, I strayed from the design for practical reasons.

This has to be incorporated and the drawing re-dimensioned. The adaptor relays a smaller 18mm image target and demonstrates a general principle only. It also does not re-erect the inverted image.

Flipping the Image
 

I think if the image can be flipped without any loss of resolution or image detail then it is good (may be we should try to see how the original was flipped). If there is a loss, then I agree with the post on using mirrors on the lcd and flipping it in post. BTW the P&S version had a 1 to 2 f-stop loss. How many stops are we losing with this version.

Flipping the Image
 

More to the previous post, I will make some calls to some optics people to see how it can be done without any loss.

Daniel can you please post some pix and what type of video camera you are using for this setup? I think this approach might work well for the DVX with a achromatic diopter or + closeup lens.

I also can live with a mirror in the LCD or a flipped external monitor. I just bought a car 5 inch DVD at Fry's for $99.
Powered by 12volts.

Thanx

Peter,

Nice box. Let us know how it works. Are you on the 3rd version because you couldn't get the others to work, or are you just trying to improve them as you go?

Also, what kind of brace is that? I want one! Please let me know...

Clay

Chris - The cat just likes to sniff the camera and make faces at me like. I'm more important than this stupid machine... pay attention to me!

It's actually funny because he jumped into the picture, I wasn't even planning on having him in the picture.


J Clayton - The support structure is:

a 3420 Telephoto Lens Support from Manfrotto/bogen (this thing almost seems like it is built for this rig... and its only like 50 bucks I think)

and a camera shoulder mount which I picked up years ago (i don't remember how much, but under 100)

Peter,

...and both the mount and the telephoto support just fit together or is there some rigging involved?

Do you know the model of the shoulder mount?

Thanks.
Clay

both of the items have the standard tripod screw... so the shoulder mount is screwed into the telephoto lens mount which is screwed into the video camera.

unfourtunately I do not know the brand for the shoulder mount, but I'm sure someone in another area of this forum could point you to a good cheap one like it... i know varizoom makes some stuff like it...

http://www.varizoom.com/pages/supportindex.php

EDIT: I think I found a model that looks to be the newest model of what I have at:

http://www.studio1productions.com/dvbrace.htm

its 149.99

you may be able to find something cheaper....

I think Studio1 actually makes that shoulder mount - I have it myself. I got it below $100 at ZotzDigital, one of this site's sponsors.

Alright...questions for those of you in the know about optics and/or those of you with a GL1 or similar cam that has an Agus35 working:

1) I cannot pull focus with my 35mm lens. I'm talking both alone and with the adapter attached.

Upon investigating -- and here my ignorance of optics will show -- I found that I need to place the lens about 6 inches from the surface of the projection (in this case, my eye) in order for anything to come into focus. Which begs the questions: 1a) how do you shrink the distance between the 35mm lens and the GG, or 1b) am I stuck keeping the lens to a distance of 6in. or greater from the GG? (i.e. making my adapter larger?)

2) Anyone having success with a CD motor/clasp setup at a proper speed? By proper, I mean that I assume these motors have a max speed they're rated for -- with the typical portable CD player runningg off of 2 "AA" batteries (3 volts), I assume hooking one up to a 9 volt battery to be a mistake.

However, running through tests today, I noticed a palpable shimmer in my (as yet focused) imagery that was directly related to the slow RPM of the motor. Hooking it up to a 9v battery cured the problem, but I have doubts as to how long the motor will run in this mode.

- jim

Ok, seens like most of you dont care about the flipped image, but i dont know about when release the product, if all user will mind about it. you can flip it in post with no trouble and loss quality, the problem comes when deinterlacing.. you must deinterlace first and then flip.


would it be too bad that you get the flipped image ?

Agus,

I think if you are going to make a commercial product and sell it that way, you need to flip the image. I personally would not want to spend around $1000 for an Agus35 and not have my image correct. Maybe you can offer a cheaper version that doens't flip the image? Give the people a choice!

Clay

P.S. I don't know any good way to do this, but I think it needs to be done. You might just study exactly how SLR cameras flip the image and then find some way to use that???

yeah, that is exactly what i was thinking about, using prism is the best solution it seens.

Flip Image


3 months ago I was holding 5 inches LCD monitor. Saleperson said "and nice feature is that you can flip the image upside down with this button"

I went to the place monitors are gone, he dosen't remember who made them. They were at around $350

Mike

P.S. They were designed for car use.

To Jim Lafferty:

Could you tell us what 35mm camera lens you're using. If you have to place it so far from the groundglass there's something not right there - unless you are using a projector lens. Some sit off about 6 inches from the film plane.

Just for curiosity sake, take the groundglass out and see if you are getting the same result direct into the camcorder. I have observed in my tests, the camera aquires the aerial image.

To All:

I dismantled the VCR16B lens set and tried that last night. It underscans the 35mm image frame into the VX2000/PD150, by about 15% so it's not a viable option. It is about 7x power, 3x was too small so 5x may be about right.

Webpage on the subject.
 

Here's a page I put together rather quickly about these adapters and the principals involved. Let me know what you think.

Paul

www.thecountrybulletin.com/dv_dof.htm

nice page. but i think if you have fresnel lense, then you don't need the magnifier cause they just do the same thing. correct me if im wrong

Danny <if you have fresnel lense, then you don't need the magnifier cause they just do the same thing. correct me if im wrong>

Things are just getting started on all of this. So I guess you could say that the jury is still out. See the links to the graphics showing the effect on the ground glass by the fresnel. It brightens the edges. The magnification is to allow your camcorder's screen to be filled with the image (24 x 36mm). I'm not trying to build that kind of adapter so I'm not sure. That's just my take on it.

Paul

"To Jim Lafferty:

Could you tell us what 35mm camera lens you're using. If you have to place it so far from the groundglass there's something not right there - unless you are using a projector lens. Some sit off about 6 inches from the film plane."

This is a standard Nikon Nikkor 50mm lens with an aperture of f/1.4. The same effect can be seen from my Pentax 50mm lens with f/1.7. They're both standard lenses fitted for 35mm cameras. Neither of them can get a focused image on my GG which sits about a 1/2 inch from the rear of the lens, and three inches or so from my GL1's macro (which, incidently, can pick up the grain on the GG fine).

- jim

Jim,

I could be wrong, if so forgive me! But, I thought the GG must be closest to the video camera lens, and further from the Camera lens. It may be a whole different can of worms with the GL series. But from what I have seen, the GG needs to be really close (1/4"?) to the video camera. You might try reversing what you have already tried, or have you? Just a thought...

Clay

XL1 image flip solution
 

Working towards a solution at reversing the image the Agus35, I had already picked up one of these great gadgets http://www.zgc.com/zgc.nsf/active/6FA3DA5F0C16A24985256B82007B576D a little shock absorber/mic/eye-piece extender. So to right side the image all you have to do is flip the mic/eyepiece arm to the other side of the support T and turn off the evf display. I'm still awaiting a few key pieces to build out my Agus35, I will be on vacation for the next few weeks but I hope to show pics and tests of my mod the early week of january.

D

Hey there, i just read the webpage from Paul, and let me tell you that i was really disapointed when i saw the diagram of the design and below it says "copywrite paul E. Doss, JR"... dont get me wrong, but it is too sad that all the work to make this adapter for free now seens to be created by some one else with no credit at all in the webpage.

the basic design was really hard to adchieve... or if you dont believe me read the from the begining of this thread... well, maybe now its not my design anymore cause i let it go for everybody, but for that reason, if it is not mine, it cant be from anyone... but for all...

hmm
 

i think you should credit/mentioned agus casse's name there dude...he sparkled this idea and he helped people to build this thing...

Agus you should better go get the Real copyrights of that thing soon man!

I have no plans of my own for building an Agus35 yet and I'm not an expert in optics, but here are my thoughts on the subject just from having read through the thread--

- The name of the game in building one of these should be preservation of light. Additional generations of reflectance/transmittance are going to substantially reduce the amount of light that gets to your CCD.
- To that end, why fool with mirrors to invert the image. This is something best done in post. If you're having a hard time visualizing on the set, put the inversion apparatus outside the camera after the viewscreen/viewfinder.
- Similarly, it's hard to imagine the amount of light reflected from a built-in white screen (as in Paul's diagram on his web site) would be as good as what's being transmitted through a ground glass.
- Someone mentioned using something other than a frosted CD as a ground glass. The nice thing about the CD is that it's already very round. Use anything with a center of mass in a different spot than the center of rotation and your implementation is going to vibrate like the dickens.
- When's the XL2 coming out again?

<<<-- Originally posted by Danny Tan : nice page. but i think if you have fresnel lense, then you don't need the magnifier cause they just do the same thing. correct me if im wrong -->>>

yea thats wrong.

The Fresnel lens is to even out the light recieved from the 50mm lens, so you dont get a really bright spot in the middle of the GG.

The Magnifier (macro lens) is so you can get your DV camera really close to the GG and be able to focus a clear image on the GG.

------------------------------------------------------------------------------

Please people- read the previous posts, I know 28 pages is daunting but its really not that hard.

"- Similarly, it's hard to imagine the amount of light reflected from a built-in white screen (as in Paul's diagram on his web site) would be as good as what's being transmitted through a ground glass."

Indeed: at best, Paul could get a regular 1.0 reflection rate for his screen. Spinning disk implies he can't get any sort of gain for his screen, because gain would make the screen highly directional. "No gain screen" means the light is gonna end up being scattered everywhere, in every direction. So lots of photons are gonna be lost in the process of reflecting the picture.

Furthermore, I just can't see how he could possibly get a correct picture geometry with this setup... The adjusting process must be daunting. Paul must be ending with a very dim and somewhat distorded picture IMHO.

Paul, why don't you take the "KISS" approach (Keep It Simple, Stupid)?

I always thought it was, "Keep It Simple, Stupid!"

"I always thought it was, "Keep It Simple, Stupid!"

Ooops! Thanks for pointing that out Robert! : )

To: Jim Lafferty.

Jim.

Perhaps we should talk about two distinct functions which happen and call them stage one and stage two.

Stage one is in effect a camera and setup (= AGUS35 system). -- Object>>>lens>>>focal plane |, in this case it's the groundglass.

Stage two is another camera and setup. -- Object, in this case the image on the groundglass>>>relay lens or close-up lens if needed>>> camcorder lens>>>focal plane |, in this case, it's your camcorder's CCD chip.

It sounds to me like your problem is in stage one. You have your 35mm objective lenses too close to your groundglass. The rears of those lenses must be the same distance forward from your groundglass as they would be from the film plane (focal plane) if still installed to the cameras they came off.

This distance will be in the ballpark of about 1 and a half inches or so, not the half-inch of so you are using. To get the exact measurement, grab the camera bodyn dismount any lens you have on it and look for a mark on the top to left of the viewfinder prism enclosure for the Nikon (FM2).

The mark will be an "O" with a line drawn through it. This line corresponds to the focal plane (film plane) of your 35mm camera.

Put a straight-edge (a ruler is fine) across the lens-mount face of the camera so that you can then measure the shortest direct distance from the focal plane to the edge of the straight-edge. That distance is the space which needs to be between the mount face of your objective lens and the groundglass. Once you get that right things should start to look a lot better with a sharp image projecting on the groundglass you can see with your eyeball.

The issue from that point will be stage two, being able to frame and focus sharply upon the image projected onto your groundglass.

Between your camcorder and the rear of the groundglass is where any of the close-up lenses, macros etc talked about here will have to be placed if your camera cannot frame close enough and hold sharp focus on that projected image on the groundglass.

To initially set this part up, forget about trying to project an image onto the groundglass and use a barcode panel off a food packet to see if you can get your camcorder close enough. The barcode will show any distortion of focus defects.

Once you've got that sorted, then you can mate up stages one and two with a lot less grief, knowing each of the stages in themselves are working properly.

This leaves you with the task of rotating your groundglass and putting the whole thing inside a nice looking enclosure. Don't forget to paint the inside with blackboard paint to eliminate internal reflection which may cause a fogging effect.

If your groundglass is not opaque enough, the image into your camcorder will have a hotspot in the centre, most evident when your objective lens on stage one is stopped down.

To all:

Best frosted effect with the plastic CD disk is achieved by finding a flat surface, (sheet of glass on a benchtop) laying on it a piece of dense soft cloth which is not going to scratch the smooth side of your disk, placing face-down on your disk, a sheet of 500 grit silicon carbide (wet and dry) paper, using a short screwdriver handle or similar blunt object with both round and straight edges, then scrubbing away to press the grit against the disk. Do not let the paper scrub across the disk as you want pits, not scratches in your disk. For the broad surface of the disk you can scrub the ridged grips of the handle across the paper. Towards the edge of the disk you will need to use the rounded end of the handle to scrub with as the disk rim is slightly raised and the frosting effect will not reach the edge.

It will take you about 80 minutes of patient work. The job will be done when you cannot see through the disk but a lens will project an image on it.

Cleanliness is next to godliness and most importantly, do not touch the ground surface as finger grease will spoil it and no amount of furthur work will remove that smooth mark. Efforts to clean it will polish the groundglass pattern because the plastic is soft.

what about the jvc hd10
 

can you tell me if theres any problem if someone makes a
agus35 on the JVC HDV CAMCORDER?

i THINK THIS WOULD BE A WONDERFUL THING!!

think about it

the resolution of HDV and the DOF

great

someone please try it.

ciao

The only thing missing would be 24P...

I have been given a little tidbit of information about how the movietube professional version was built, i am going to try and get all the parts together tomorrow and build it over the next few days.

If all goes well i will post the plans, it will be nice to have a complete version which is very small and has no moving parts.

BTW, has anybody built thing for a dvx-100 and knows if it needs a diopeter or not?

Zac

cosmin rotaru says in a early post to agus that he should use a fresnel lens in order to get rid of the hot spot on the GG. Another user posted a link to an american store who sells fresnells, i live in europe and i have not been able to get a fresnel to eliminate the hot spot on my agus35. does anyone know where they're sold in europe? or perhaps another device where they can be taken out?

thanks

Thomas

Use a dove prism to flip the image.

http://www.doveprism.com/