In the past, I discovered some easy way to evenly coat without bubbles (not to do with GG acid), but I don't remember how. If you get something the same consistancy/texture/stickiness as the acid compound, and try different methods on a test glass, I am sure you'll also eventually find it.

I havent worked with acid yet but as long as it doesnt act like oil when you add water to it I would think the thing to do would be to water down the acid to a much less powerful, perfectly even mix BEFORE applying it to the glass. I should take a lot longer for the acid to etch away at the glass but this is a good thing as you can move the solution around while it slowly works on the glass and it should NOT be strong enough to cause any particular unwanted patterns on the glass. Instead I would think in the end it would be very even etch. Has anyone tried this? Like I said if water can be mixed in with the acid without them seperating (like oil and water does) then it should work.

-Brett Erskine

Good thought
 

The acid does dilite with water. Diluting it first would have made the stuff 1000 times more easier to work with... thanks Brett for the tip. I'm gonna try that.

John

acid
 

I also tried the etching a week or so back and was completely unsuccessful. Patterns everywhere. In fact the grain was more prominent than on my WAO5 GG.

Has anyone tried a partial polish-back of acid etched surfaces?

Somewhat OFF TOPIC: Who emailed me for grit?
 

I received an email recently regarding buying some of my extra 6 micron grit, but I hit "delete" instead of "reply" by mistake - the person said they found me email from this thread , so please resend the message.

Bob, I did and it worked fairly well. Somewhere along the line I got a acratch on my smooth side of the glass, so it is no longer any good. What I did end up with was really too frosted. Realize though I had ground the glass twice, then acid etched, then polished. Therefore, my results may not be a good benchmark.

John.

It's early days yet but I am getting better results in manual tests polishing the Ohara disks by using a heavy bronze donut shaped piece of metal I intend to use in the tumbler when I get it built.

The reason why I tried this was that whilst I was manually rolling the donut inside a rotating CD-R case with polish slurry to see what was the best angle for a smooth movement of the donut.

After cleaning the Ohara disk, I found polished tracks which had occurred in just a very short time and with no pressure except the weight of the donut.

I think the hole in the centre has something to do with it.

For your smaller filter disks, it may be possible to restore the front face if you dress with your 5 and 3 micron then polish with the cerium oxide if you are using this with a small bronze donut about the size of an alternator bearing.

The larger donut of about 60mm with 20mm centre hole is about 10mm thick. I faced it on a lathe and cut circular grooves in it at about 2mm spacing. You can get good polishing friction with it but no sticking or rough binding.

How it goes for scratches I have yet to find out as like your own efforts, the experimental disk has been abused through previous unsuccessful efforts.

To avoid bending and cracking my disks I placed them on the sheet of glass I have been dressing them on.

James Webb
 

Bravo.

Alain
 

merci beaucoup.

WOW gang I just finished my spinning35 and all I can say is AMAZING!! this thing turns the word VIDEO upside down and inside out! it's just AMAZING how film like the images look now! I feel like I would NEVER want to shoot standard VIDEO EVER again! rockon!


now I have to build a rail system to mount the puppy on the bottom of the dvx100! btw for anyone that is having problems with using macro +10 lenses to get the thing to work on the dvx100 I have found a way without them by using a bigger PCX glass and having it VERY close to the dvx lens

Obin -

I'd love to hear about the PCX

- Damion

www.dv3productions.com/test_images/dvx100_spinning35.jpg

I jsut LOVE the grain it gives images!

Obin
 

Nice job!

Can you tell us the exact brand/model PCX and where you purchased it?

Thanks.

that website on the threads here that has stuff for cheap lots of optics I bought 2 PCX lenses I think a 50mm and an 80mm or something like that...that image above is out of focus I will try and post more
www.dv3productions.com/test_images/color_work_35.jpg

this is like god has come down and given me the creative ability I have been searching for as a digital DOP..I LOVE digital and hate it at the same time....this spinning35 really changes that for me as a shooter/editor

Obin - A few questions
 

Obin-
1)Are you using the DVX100 or the DVX100A? Whats your Z#&F#?
2)Whats the focal length and diameter of the PCX lens you are using?
3)Could you measure and post the measurement for the gap between your PCX and the very front of the DVX100's glass lens?
4)Sounds like there is a gap between your GG and the PCX lens. Could you measure and post that distance as well.
5)Lastly please post a picture of your adapter.

With all of these questions answered it will be clear to everyone why and how your design works. Thanks.

-Brett Erskine

Also it looks like you have some heavy light fall off on the edges of your frame. Did you check to see that your camera is able to zoom in and focus on a 36mm X 24mm frame size area of the GG? If it is then the problem is that your PCX isnt fully correcting for the light fall off. You would need to get a PCX lens with a slightly shorter focal length to fix that. BTW how did you go about rotating the GG?

-Brett Erskine

one thing great about the spinning glass(cd) is that every frame has a new pattern of grain because it is spinning so I never have the effect of having a net infront of the screen

pcx is VERY VERY close to dvx lens I took the square lens plstic protector off the camera so that the pcx almost touches the dvx lens and the gg is I would say 5-10mm away from the pcx this way it enlarges the gg a bit. soooo get your pcx VERY close to camera lens and keep the gg a bit back and it works! I may end up using a +4 diopter to get that bit of balck off the screen in the corners but I only see that at full WIDE on the canon 28-135 zoom

how can I get a PL mount for this unit? I want to get old cine lenses for the unit

Lens: PCX, Dia: 59.70, Focal: 62,

and

Lens: PCX, Dia: 52.60, Focal: 80, Coated

is what I bought I used the focal 60 lens the focal80 had a hotspot

odin's technique
 

I have a PCX that I'm usingin instead of the two +10 (crappy) macros I bought off of Ebay and it appears to work as Obin says. I just can't seem to figure out a way to secure the PCX to the front of the DVX. It's a piece of glass, dia: 52.60mm Focal: 80mm. The distance that I have the flat side of the PCX from the DVX lens is the exact distance if you just rest the flat side of the PCX on the little plastic piece that's screwed on in front of the lens. THen the distace that seems to work for focusing on the GG is is to place the GG approx 13 to 15mm from the cameras 72mm filter threads. I have a quantray and tiffen 72m filter ring in between the camera and GG (which is one of those crappy macros I mentions with the flat side ground). I put a 35mm slide onto the GG to measure the areas that you can focus on at that distance and it appears to be between 34 and 36mm widthwise. My DVX focus is at 00 and my Zoom is 60. As soon as I can figure out a way to secure the piece of glass to that plastic piece, I can give you much more exact measurements... but the tests I've done seems to say these are very close.

John

I have the PCX flat side AWAY from the camera lens facing the GG...john why do you have it the other way?? how can that work?

thinking about dropping the PL idea and staying with the canon mount...I see a set of 28-80mm and 70-300mm Tamaron lenses on the net...any feedback good/bad on them? why would I NOT want to set down $180 for the set brand new?

does anyone have an easy way to flip the image BEFORE it hits the camera lens? I got this far...can't be too much harder can it?

PCX
 

Obin,

When you first posted today I dug around for those lenses I purchased a while back and started playing around. Putting the 52.60/80 flatside towards the DVX and resting on the plastic piece works perfectly for me. No hotspot, and no distortion. RIght now I'm just using double stick tpe to hold the lens on but I know that won't hold for long term use.

John

odd that did not work at all for me...it was all warped when looked at on a monitor...found what we all need to buy for our poor focus pullers using the 35mm lenses:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=180&item=5700645539&rd=1

Flipping the image upright in the optical path is not all that hard. It is however a costly exercise compared to making the Agus/Aldu alone.

You need two right-angle prisms with enough length on the hypotenuse face to accommodate two full frames of your groundglass image. To be safe you need 40mm prisms which give you about 52mm on the hypotenuse face which gives you enough for a standard academy aperture frame. For a 35mm still camera frame you might need to go to 50mm prisms.

These prisms are arranged in 90 degree opposition to each other as in a prismatic binocular or telescope ( porro prisms ). Image in is inverted. Image out is erected and the right way around.

The prisms are costly, heavy, have to be mounted and aligned precisely in a way which does not injure them through local pressures, shock loadings surface contamination or movement.
Surface coated mirrors are a less heavy alternative but also require the same precision and care.

A suits-all zoom-through optical path is less likely to evolve than for the Agus/Aldu adaptors themselves which are relatively simple.

The difficulty experienced in catering for the 72mm lens front-end camcorders illustrates the likely difficulties with a much more complex optical path.

(For small camcorders, the smaller CD-R disks spinning at a faster rate or small fixed filter/groundglasses would be more in keeping with their light wieght and user-friendliness.)

For image erecting, small 37mm front-end handicams might get away with a 30mm prism/mirror pair. A 40mm prism/mirror pair seems to suit the PD150/VX2000 camera family and possibly other camcorders with 52mm front lens diameters (filter attachment is 58mm, not the front lens element).

Whatever you use, the Aldu35 adaptors will no longer be a simple self-centering screw and glue affair because it will have a dog-leg shape.

Likewise for the Agus35 which will likely have to lose the CD-R case which was the original attraction because of its low cost and simplicity.

For the sake of erecting the image into the camcorder, which we can correct in post, there may be an extra penalty of furthur definition and light loss. Do we really want to go there?

I do but then I am possibly a glutton for punishment. When I have my arrangement sorted I will advise. My initial thoughts are to use fine-grained craftwood to hold the prisms, rather than metal because of the wood's cushioning effect and easy workability. There's lots of cutting an shaping to do. For mirrors a folded sheetmetal arrangement would work but for prisms it would not.

Good luck.

ouch! maybe post will have to do...OR shoot upside down ;)

Has anyone here tried using an Aspheric PCX lens as a condenser? I'm curious about the quality of one of those and if it beats a spherical PCX.

Shooting upside-down with one's back (and fat backside when bending over to a low mounted viewfinder) towards the subject is quite workable after practice and getting used to operating the controls in the new position. The hardest part is the passing public and their questions.

The Agus/Aldu plus camcorder combination is a little more tricky to set up and maintain quality with under pressure of any live event, so a sound recordist or camera assistant is desirable.

Obin's adapter
 

Obin can you post a picture of your adapter? Also how did you create your ground glass? Are you using aluminum oxide?

<<<-- Originally posted by Obin Olson : does anyone have an easy way to flip the image BEFORE it hits the camera lens? I got this far...can't be too much harder can it? -->>>

i think you can find many different solutions in static solution thread

check this link

http://www.dvinfo.net/conf/showthread.php?s=&threadid=18690

and many different solutions are somehow mentioned also in aldu/adus thread or in discussion about upside down monitor solutions. take a closer look.
think about porro prisms or roof prism with amici prism. but then you are closer to the mini35 then to aldu due to physical limitation of those solutions (they are not in straight line like aldu)

filip

Obin
 

Regarding the image flipping... this was mentioned once before in a post by someone... I've always found it interesting and wonder why it's not been mentioned more as a viable solution.

http://www.leadtools.com/SDK/Multimedia/Direct-Show-Filters/Multimedia-DirectShow-Rotate.htm

Due to the real-time effects in most editors now, many users have decided that flipping the image in-camera isn't very necessary or worth the extra time and money. That program does look handy, but will be soon outdated, if not already.

Handy
 

Agreed that inc amera flipping isn't ideal for this kind of project. But capturing the footage flipped would at the very least save you time at final render. Now if there are as you say other tools that have or are about to surpass this piece of software in affordability and accessability, then the members of this forum need know about them. That's what we're here for. Till we know what else is out there all we can work with is the best of what we have.

John

I called up the website but with my browser and slow landline (785bps to 5k), the computer started going in circles before it managed to download the page, so I didn't perservere.

This is my first post, first off, big props to aldu and alain for their contributions, simply incredible. Secondly, Ive built both versions, just finished my static and have a couple of pictures (short clip as well), who can I send these to for all to see?

Thanks

Pat

There's a number of people here who might host images who may reply to your request. If you email Chris Hurd at :-

"chris@dvinfo.net"

with a request, he may set up an address here which might look like :-

"www.dvinfo.net/media/worrell" or similar. I have been posting my bits and pieces here through his favour by sending via email attachments.

My stuff is at an archive at :-

"www.dvinfo.net/media/hart". If viewed by date it might give you an idea of how the image quality evolves. Lately it has taken a step backwards as I have been experimenting with glass disks.

I built a platform which holds my spinning glass adapter and a mounting device which holds the camcorder up to the adapter upside down. I use an external monitor during recording, so I get image through the adapter on tape and on monitor while viewing which is optically correct. Works well.