Question for Bob Hart at DVinfo.net

Leo Mandy · December 28th, 2004, 08:42 PM

Hello Bob,

I have been reading your post with both admiration and fascination. I think I am at a point where I want to build the Agus35. Here are the list of part I have, could you please tell me what I still need -

1. case for a DVD 25 pack
2. motor from a CD player
3. frosted disc
4. DV camera

Now, I remember people saying that you need either a magnifying lens or a fresnal lens - so I am not sure which it is. ..

And I guess I am going to need a 35mm SLR, correct?

Thanks in advance.

Mandy

Bob Hart · December 29th, 2004, 12:17 PM

Mandy.

Firstly, I should make a correction here. By "post" I guess you refer to the Agus35 thread in which case the starter of the thread and the worldwide construction of the devices, Agus Casse himself should be acknowledged.

I am by no means an expert on the subject and my engineering skills remain in the realm of bending pieces of sheetmetal with pliers and dabbling in a bit of metal turning.

There are as many flavours of the AGUS35/ALDU35 themes as there are camcorders and lenses people have brought together in functional relationships never intended by the original designers.

These were never formally arranged marriages, that's for sure and it is a tribute to the original products that they perform as well as they do under the circumstances.

There is not really any "one size fits all" CD-R case based device I can help you with except Agus Casse's original which you should enquire with him for as I have not built one.

You can cobble together a perfectly useful appliance with US$20 worth of parts but how long and reliably it will perform is another matter.

You should examine :-

What do you want the device to do for you? Is it to perform at an interest and hobby level or is it to become professional level hardware?

Can you afford the down-time if the device fails on a shoot?

Can you accept an inferior result on-screen if it doesn't work first time every time?

How much personal time and effort can you afford to invest in making the device?

If you intend to build, do your manual skills extend to making things to the accuracy of the thickness of a fine-point ballpoint pen line?

How much can you afford financially? As with computers, with imaging, rubbish in = rubbish out. For acceptable results you need good SLR lenses which are not cheap. Do you want to hang a valuable lens on front of a camera mount glued onto a CD-R case/hose-clip/acrylic sealer/gaffertape combination which might fall off lens-first onto the concrete patio from the balcony above during a shoot? - Probably not, which takes you up a level into the realm of making something more robust.

If you move up to building something more elaborate, is the effort worthwhile if your camcorder is not capable of resolving better than 500 TV lines of image quality and the automatic functions can be over-ridden to allow shutter speeds of 1/50th of a second to be held to. If not, do you spend more money on another camcorder just to be able to use an Agus35 style device.

A US$20 build may get you to let's say about 85% of the image quality of the Mini35. Beyond that, the incremental improvements become more difficult and expensive to achieve. To build an AGUS35 to the full functionality of the Mini35 might well cost more than the Mini35 itself.

Can you afford to have a production stalled by legal injuctive action taken against all Agus35 video origination even though this might be unlikely?

There is a good tutorial to be found on the web on a project case-based version of Agus Casse's device. The construction method and materials chosen, lead to accurate centering and alignments providing the skill levels are also available.

It is as near as I have seen so far to being a universal design yet capable of reliable and consistent performance. Several constructors have reported satisfaction with their builds of this version.

My memory fades but I think the tutorial was assembled by Jim Lafferty. Do a google or altavista search on AGUS35 and anything on the web which comes up with something like www.diaspora ??? in its text will be where it's at.

My own versions are extremely limited to plumber's hardware available in Australia, the Sony DSR PD150-170/VX2000-2100 camcorder families and Nikon F series compatable SLR prime lenses.

All that said and gone, here follows a very basic summary of what the AGUS does and what is needed for Nikon to PD150.

Good Nikon SLR prime lens,( preferably f1.8 aperture) >> a Nikon style lens mount from a camera repair store >> 46.5mm of space from lens-mount flange to groundglass >> a groundglass rear-projection surface, usually a plastic or glass CD-R shaped spinning disk dressed with a five micron abrasive >> about 120mm to 130mm of space from the groundglass to a +7 close-up or macro lens attached to the video camcorder. (This lens is preferably an achromatic diopter made of two pieces of glass not a single piece of glass because a single close-up lens tends not to be sharp and you can get rainbows on the image edges .)

All these things have to be held in place by a light-proof case which holds the center axis of the Nikon lens true to the center axis of the camcorder lens and the close-up lens attached to it. The camcorder should be connected to the appliance by the tripod mount screw and a good baseplate, not the filter thread mount or lens hood bayonet mount fitting.

The disk needs a CD player motor and hub to spin it, one or two 1.5v batteries for power, a one or two-cell battery holder, some hookup wire and a small switch.

This layout of the AGUS35 gives you an image into the camcorder which in the viewfinder is upside down. To get the image the rightway up, you need to operate the camcorder upside down or flip the image vertically and horizontally in postproduction.

This version gets you up to about 85% of the image quality of a Mini35 depending on the quality of the groundglass finish and the quality of the close-up lens you attach to your camcorder.

Things like fresnel lenses and condensers are added when attempting to get closer to the best quality image.

December 28th, 2004, 08:42 PM	#1
Leo Mandy Major Player Join Date: Dec 2004 Posts: 749	Question for Bob Hart Hello Bob, I have been reading your post with both admiration and fascination. I think I am at a point where I want to build the Agus35. Here are the list of part I have, could you please tell me what I still need - 1. case for a DVD 25 pack 2. motor from a CD player 3. frosted disc 4. DV camera Now, I remember people saying that you need either a magnifying lens or a fresnal lens - so I am not sure which it is. .. And I guess I am going to need a 35mm SLR, correct? Thanks in advance. Mandy

December 29th, 2004, 12:17 PM	#2
Bob Hart Inner Circle Join Date: Dec 2003 Location: PERTH. W.A. AUSTRALIA. Posts: 4,477	Mandy. Firstly, I should make a correction here. By "post" I guess you refer to the Agus35 thread in which case the starter of the thread and the worldwide construction of the devices, Agus Casse himself should be acknowledged. I am by no means an expert on the subject and my engineering skills remain in the realm of bending pieces of sheetmetal with pliers and dabbling in a bit of metal turning. There are as many flavours of the AGUS35/ALDU35 themes as there are camcorders and lenses people have brought together in functional relationships never intended by the original designers. These were never formally arranged marriages, that's for sure and it is a tribute to the original products that they perform as well as they do under the circumstances. There is not really any "one size fits all" CD-R case based device I can help you with except Agus Casse's original which you should enquire with him for as I have not built one. You can cobble together a perfectly useful appliance with US$20 worth of parts but how long and reliably it will perform is another matter. You should examine :- What do you want the device to do for you? Is it to perform at an interest and hobby level or is it to become professional level hardware? Can you afford the down-time if the device fails on a shoot? Can you accept an inferior result on-screen if it doesn't work first time every time? How much personal time and effort can you afford to invest in making the device? If you intend to build, do your manual skills extend to making things to the accuracy of the thickness of a fine-point ballpoint pen line? How much can you afford financially? As with computers, with imaging, rubbish in = rubbish out. For acceptable results you need good SLR lenses which are not cheap. Do you want to hang a valuable lens on front of a camera mount glued onto a CD-R case/hose-clip/acrylic sealer/gaffertape combination which might fall off lens-first onto the concrete patio from the balcony above during a shoot? - Probably not, which takes you up a level into the realm of making something more robust. If you move up to building something more elaborate, is the effort worthwhile if your camcorder is not capable of resolving better than 500 TV lines of image quality and the automatic functions can be over-ridden to allow shutter speeds of 1/50th of a second to be held to. If not, do you spend more money on another camcorder just to be able to use an Agus35 style device. A US$20 build may get you to let's say about 85% of the image quality of the Mini35. Beyond that, the incremental improvements become more difficult and expensive to achieve. To build an AGUS35 to the full functionality of the Mini35 might well cost more than the Mini35 itself. Can you afford to have a production stalled by legal injuctive action taken against all Agus35 video origination even though this might be unlikely? There is a good tutorial to be found on the web on a project case-based version of Agus Casse's device. The construction method and materials chosen, lead to accurate centering and alignments providing the skill levels are also available. It is as near as I have seen so far to being a universal design yet capable of reliable and consistent performance. Several constructors have reported satisfaction with their builds of this version. My memory fades but I think the tutorial was assembled by Jim Lafferty. Do a google or altavista search on AGUS35 and anything on the web which comes up with something like www.diaspora ??? in its text will be where it's at. My own versions are extremely limited to plumber's hardware available in Australia, the Sony DSR PD150-170/VX2000-2100 camcorder families and Nikon F series compatable SLR prime lenses. All that said and gone, here follows a very basic summary of what the AGUS does and what is needed for Nikon to PD150. Good Nikon SLR prime lens,( preferably f1.8 aperture) >> a Nikon style lens mount from a camera repair store >> 46.5mm of space from lens-mount flange to groundglass >> a groundglass rear-projection surface, usually a plastic or glass CD-R shaped spinning disk dressed with a five micron abrasive >> about 120mm to 130mm of space from the groundglass to a +7 close-up or macro lens attached to the video camcorder. (This lens is preferably an achromatic diopter made of two pieces of glass not a single piece of glass because a single close-up lens tends not to be sharp and you can get rainbows on the image edges .) All these things have to be held in place by a light-proof case which holds the center axis of the Nikon lens true to the center axis of the camcorder lens and the close-up lens attached to it. The camcorder should be connected to the appliance by the tripod mount screw and a good baseplate, not the filter thread mount or lens hood bayonet mount fitting. The disk needs a CD player motor and hub to spin it, one or two 1.5v batteries for power, a one or two-cell battery holder, some hookup wire and a small switch. This layout of the AGUS35 gives you an image into the camcorder which in the viewfinder is upside down. To get the image the rightway up, you need to operate the camcorder upside down or flip the image vertically and horizontally in postproduction. This version gets you up to about 85% of the image quality of a Mini35 depending on the quality of the groundglass finish and the quality of the close-up lens you attach to your camcorder. Things like fresnel lenses and condensers are added when attempting to get closer to the best quality image.