Read my previous post (RMPP) as to why no one is using fresnel lenses anymore and are looking at condensers.

My order of 1000 grit aluminum oxide arrived from The Rock Shed today.

I got a new piece of glass, made sure it was clean (and made sure the two oxide sizes didn't get mixed), cleaned the ground glass, and started grinding with the 1000 grit. Immediately I felt something bigger in the mix while grinding. Felt like a grain of sand or something. So I cleaned the surface and the ground glass and found some very noticeable cuts on the ground glass.
I started the whole process over, and repeated this four or five times. It seems that the 1000 grit oxide from the Rock Shed isn't pure 1000 grit. I haven't heard anyone else complain about this, but I thought I'd mention it. I had to go back over the glass with 600 grit to get rid of the scratches.

Brett: Thanks for checking that link out. I will give them a call and find out. Thanks!

Frank-
Have you tried Aluminum Oxide 9Y? Alain recommends it and from my research it seems to be the finest grit you can get. Anything finer actually polishes instead of creating a ground surface. Do a google search to find it.

Also Im using two UV filters that have a multicoat finish to reduce internal reflections inside my adapter housing. One UV is for the GG and the other is right behind the 35mm lens to seal the adapter from dirt getting on the GG and coming into focus. The coating may be over kill but when I saw the two filters facing eachother before the GG I thought there could be a possible reflection problem. Getting UV with multicoating in a 55mm size is hardly a big investment and at the very least worth the piece of mind. Make sure they also have the removeable retainer ring so you can take out the glass to grind it for your GG.

-Brett Erskine

Thanks, Brett! I'm going to check into that 9Y stuff now.

Yeah, I thought that was a good idea that you mentioned earlier about the 2 filters. I likely would not have thought about that reflection problem. Thanks!

,Frank

Rockshed grit worked just fine for me...

- jim

glass cutting workshop
 

i just find a glass/mirror cutting workshop and asked a guy is there any possibility to use "1000" aluminium oxide in his workshop and make me a GG. no problem, since he is already making some matte glases for the kitchen/bathroom furniture. next day i received nice GG. (it's 52mm diameter from UV filter) deal was 5$. no scratches, nothing. maybe this is not proper way to do it (this is definitelly NOT a DoItYourself case), but it looks this will work for me. will check with the adapter any day...

filip

Scratches from 1000 grit AO
 

I've been messing around with the 1000 grit AO I got from the rock shed for about a week. I too experienced the "mysterious scratch" phenomenom early on. After some investigation, I don't believe the AO is the culprit. It is pilot error. You have to keep the grit well hydrated (lubricated) and you must constantly move the piece you're grinding around on the grinding surface. Here are some guidelines I follow now and I'm quite pleased with my results.

1. Minimum 8"x10" glass grinding surface (keep the glass filter moving to new areas of the grinding surface)
2. More water than you think and less AO (the AO should be suspended in the water on your Grinding surface, not a paste. There should be enough water for each grain of the AO to be seperated from its brothers)
3. Use light, even pressure for grinding (don't get into a hurry)
4. If you feel a change in the friction, STOP! ADD MORE WATER!
5. Wash away the used AO often and add fresh AO and water. (I think the waste glass is binding with the AO and is baically creating little bits of sand.)

I hope this saves someone some time.
I'm waiting for a set of experimental plano convex lenses to test with my static and dynamic adapters. I really like the way this adapter is shaping up.

Brett,
I'm looking to buy a DVX100A. Are you developing your adapter for the 100A or the 100? I understand that the "A" has a much shorter minimum focus. What strength diopter are you using? Thanks, Joe

High-Def Cameras with Aldu35
 

Hi all,

Please note a new thread dedicated exclusively to Hi-Def Digital Cameras (not DV) with Aldu35 adapter.

It's here:

http://www.dvinfo.net/conf/showthrea...408#post154408

LINK
 

Very nice link for DoF

http://www.dof.pcraft.com/dof.cgi

i was wondering if i could purchase a custom Aldus35 off one of you experts!

Joe-
I have the DVX100 (not the A). With the DVX100-A better minimum focus you will only need about a +10 diopter for still lenses. Buy only ONE Hoya +10 achromat diopter. Your still going to need more than one diopter if you plan on using cine lenses. I havent done test with the DVX100A but if I had to guess right now I would say you need a total of about +13. Get the A if its about the same price. Should make your adapter just alittle bit smaller than with the regular DVX100.

-Brett

I was gonna put some footage up but I decided to screw up my GG, accidentaly broke it in half. Whats a good quick source for UV filters? BestBuy?

anyways...no footage :( but before I broke the GG the footage looked outstanding, I just HAD to try to get the GG finer...then broke it.


I havent been all-stop though. Here is what ive done in the meantime. I made this rail dealie., this thing is rock solid.

pic
http://aequantum.com/DSCF0003.JPG

John

The Century F to C adapters appear to be on back order probably due to demand from miniD35 enthusiasts. I will try the more expensive Nikon version that is still available.

Griding conenser
 

some one try to grind direct one condenser lents ???

i mean

____________! condeser lents whit grind on flat size
____________v___macro
SLR lens ----> [) () ----> dv cam

JUSTE like Nikon type D focus screen

less stop lose one glass less

another question:

if i use condenser lents whit flat surface directed to SLR lens

BFL (back focal lenght) shut bee the same as SLR focal flange ???

see image at http://www.edmundoptics.com/IOD/DisplayProduct.cfm?productid=1747

I've been following this thread the past few days. This is amazing stuff going on. But I have one question. Is ground glass absolutely necessary? That is, is it an essential part of creating a DOF lens adapter or is it for aesthetic texture purposes only? I would love to get going on building one of my own but I'd prefer getting the cleanest image possible and adding grain/texture in post - the depth of field adapter being the only thing I care about. Is the ground glass essential? IF not, how would this affect the setup so far?


thanks for your time and commitment, and kudos to everyone.