Brett I am still waiting for an answer from you about testing your unit with the HD camera I am building..would you care to email me at

oolsen1@ec.rr.com


thanks a lot!

Sure thing. Sorry about that. Check you mail box.

Any sample footage yet, Brett ?

-Les

Sorry to leave you hanging. I've been busy working alot lately so I've been forced to put the project aside. The very day its showable I'll post it on here.

Final Consesus on the Design?
 

Folks,

I am about to go into a design meeting with a design and prototyping company here in Salt Lake City to see about developing CAD drawings and data files for CNC and 3D printing machines.

I have read every message on this thread, many twice (for you Brett!) -- However, I was not able to find a final concensus on the design regarding the use of Micro focus screens (without markings) and/or the need/quantity of condenser lenses and their orientation?

If anyone can help me out here in the next hour, I would appreciate it. If you have specifics, please email them to me directly. I will post later this afternoon or tomorrow the results from our meeting.

km

No go
 

After extensive experimentation and sizable investment into the test equipment/parts, I have come to the following conclusion:

- The quality of the video with even the best of the adapers (be it self-made or P+S pro system) is subpar to the extent that I consider unacceptable.

Note that I operate HDV cam, not SD DV. However I have the same opinion of the adapters in DV applications as well, sorry.

Therefore I stopped experiments. At this time, there seems to be no way to have a reasonably priced 35mm adapter for DV or HDV cams that produces no visible image degradation.

I guess the best bet is to wait for the HD/HDV cams that may feature large, 35mm-alike sensor areas so 35mm lenses (primes or zooms) could be used on their bodies interchangeably.

Until then, I'll just stick with the original lens system on my HDV cams. There's no room for further image degradation as introduced by the adaptors, in my opinion.

Thanks for your insight -- so long!

- jim

I've recently finished a feature length film to be exhibited at San Sebastian and Cannes.(official competition)
It was filmed with a Pana DVX100+Mini35.
It looks really nice.We couldn't find the image degradation you are talking about and it looks really amazing after transferred to 35mm.
Don't know about HD cameras with the pro adapter.It is always the same, some people say it is ok some other say it is a no go.
What really counts is what you see at the final stage I guess....

Re: No go
 

Alex, other than the slight vibration from my temporary setup, what was the image degradation you speak of from my mini35 type GG orbiter ?
My JVC HD 720P test , that I posted, didn't seem to reduce the resolution more than a few percent.
Perhaps you got burned out with all the grinding elixirs and magic methods that all show grain, especially on HD ?

It is interesting to note that the crazed postings from the 35mm adapter folks has faded away for the most part! Very few posts of working setups in high quality video.
Let me know if you need a link to my sample video.
-Les


<<<-- Originally posted by Alex Raskin :

Note that I operate HDV cam, not SD DV. However I have the same opinion of the adapters in DV applications as well, sorry. -->>>

My own subjective sense is that for HDTV, all the home-made flavours of MINI35 will fall short.

For MiniDV however, I am a little less jaundiced. The spinner version as primitive as I have made it yields 530 TV lines on a test chart which is the resolution wall as far as a PD150 is claimed for. With a better relay path than my telescope eyepiece, the result should be better.

The apparent resolution of normally aquired imaging direct into and from MiniDV appears to be sharper than an AGUS35 image.

How much of this is related to straight edges produced by the pixel rows? Put a highly contrasted finely textured MiniDV image up on a high resolution monitor and it looks dreadful.

What I have learned about the AGUS35 version I have made is that I need to pay far more meticulous attention to focus and the aperture setting/ND filters of the objective lens and relay path if I want the results.

Juan, Les and Bob: the pro adapters I've seen do introduce either grain, flicker, or both, at least under some conditions.

Static adapters introduce grain, light diffusion, or both.

No go.

I have to make the admission that subjective opinions from viewers totally not into the making of images have been that something was "wrong" with my Agus35 imaging. That does raise a flag for me.

Certainly, it doesn't remain consistent enough with non Agus35 imaging to intercut unless a different image style is deliberately chosen to distinguish certain portions or moods within a presentation. That then makes it a useful complementing tool.

It is also useful for creation of an entire presentation if a particular look is sought.

Horses for courses. From VHS through to 70mm motion film imaging.

Hi Les,

I'd be interested to see the sample footage if that was an open offer.

I was following this thread for a while back, there was talk of a holographic material for the GG but I never heard how it turned out. I guess it didn't work?

Cheers
Dan

For 35mm SLR still camera lenses, investigate the Carl Zeiss Jena lenses for Canon T50 or similar. The Jena-Zoom seems less inclined toward hotspotting than others.

Sorry if this has been asked before, but do I need to grind with anything BEFORE I start with the WAO 5?

Also, what's the general consensus on how long it takes of grinding with WAO 5 to get a good result?

Thanks.

Steve.

I'm not the resident expert on this subject however my understanding is that if your intended groundglass has already been finished high quality as an optical filter, all you need to do is use the 1500.

Weldeing goggles glass replacements may need more thorough finishing. If low (semi-clear) spots become evident in the 1500 work you may need to go back a grade then re-dress with the 1500, otherwise perservere with the 1500 until they are gone.

Recommended practice is to move your intended groundglass over a fixed dressing surface.

Some people use a sheet of glass. On glass, some problems with pickup or clinging have been reported. This leads to excessive contact pressure which causes scratches and gouges.

A machined piece of bronze or brass as a dressing surface yields a good result. Cast iron is used by the industry but I understand it may be a special grade which does not have hard particle inclusions in it. I found ordinary cast iron scratched my glass. Aluminium was also no good. It caused scratches and wore away too quickly which killed the grit slurry.

Before you commit your intended groundglass to the process, go along to your nearest pathologist and obtain some microscope slides to practice on. These give you a good feel for it. The feel as you work the glass has a lot to do with the results you get. Keep working on the microscope slides until you can achieve a result without gouges or scratches. It is frustratingly pointless trying to do it any other way.

Finally, cleanliness is next to godliness in this process. If you leave the project unattended and you have pets, you can guarantee contamination with dust or house grit in your absence.

Your intended groundglass needs to have a chamfered edge on the intended groundglass side otherwise the edge corner will sharpen, flake off then roll under into the slurry and gouge your glass. You will need to do this to your microscope slides. The intended groundglass will already have a chamfer if it was an optical grade product but check it anyway.

One of those new little diamond laps for sharpening knives is good for this task. Do it under running water.

Sorry to disagree, but this isn't the case, Bob -- you're increasing the likelihood of scratches and the amount of time required to get a uniform surface this way.

Move your grinding glass over your GG -- in this was you maintain a more even pressure across the GG's surface. It's uneven pressure and dry slurry that cause scratches, and scratches take hours to properly grind out.

Properly mixed slurry and care taken will yield a great GG within a half-hour. Be sure to:

Pre-mix grit and water to ensure a thorough soaking of the grit.

Mix this "paste" with even more water at grinding time (grit to water ratio should be about 1:5, respectively.)

Keep your glass on an even surface.

Check your GG and grinding glass surfaces for dirt prior to grind.

Err on the side of caution when replenishing your slurry -- do it early and often.

- jim

Found an interesting GG. I'm not sure if this has been posted before.

http://www.satinsnowglass.com/index.html

Has anyone used one of these before? If so how was it and how much light does it lose?

Seems promising at least (and probably well known to medium format shooters)

Satin Snow glass
 

Aaron-

Nice find!. They can cut to any size, dont have any gridelines on it, nearly no grain, and did you check out that price?!

Just ordered ordered one. I'll post my results.

-Brett Erskine

I think my brain skipped. ;-)

Yeah same here :D

I was absolutely shocked by the price. Especially after going through lots of other GG pieces on-line and seeing their prices!

Looking forward to seeing your results!

Actually I was just looking at their website again and it seems they are located in Montana - same state as me. I'm going to contact them and see about going down to have a chat.

Re: Satin Snow glass
 

<<<-- Originally posted by Brett Erskine :

Just ordered ordered one. I'll post my results.

-Brett Erskine -->>>

Please do -- I'm hesitant because they compare it to 125grit GG -- it's little wonder it compares favorably.

Apparently micro wax is the way to go for most medium format photgraphers -- the Bosscreen is highly sought -- so I'm going down that path next...

- jim

They quoted me a 3-4 week shipping period. They are going to try and get it to me in 2. Either way it will be a little bit before I can get back to you guys with info. I'll let you know.

"Sorry to disagree, but this isn't the case, Bob -- you're increasing the likelihood of scratches and the amount of time required to get a uniform surface this way." ----

Which is why I took care to announce I was not the resident expert.

Thanks for the correction Jim. One more poor innocent is saved a few hours of useless puersuit down a dead-end.

None of us are resident experts :D Your contributions have always been helpful.

Quartz
 

I am very very new to this but I've been reading for hours for the past few days (I don't really know an F-stop from a stop sign).

This may be out of place in the "static" adaptor post...but its a quite different idea from the spinning CD style. This may seem like a stupid question...but is there anyway that the GG could be made of quartz? I would imagine if you made it out of quartz you could take advantage of the piezoeletric effect and put a small high frequency ac voltage across the GG and then it would oscilate without a whole lot of noise. I realize this raises a whole lot of issues, but the main question is could quartz make an acceptable GG?

Matt

Brett,

Any luck with the SatinSnow GG?

Satin Snow GG
 

Its finer grained then anything I've made before...but its not grainless. You will still see grain with this glass. Its better then anything I used but not the perfect solution Im sure everyone is looking for. However it should work great for oscillating adapters.

Does anyone on this board have a Kit I can buy? I LOVE my 35 adaptor but the build quality is low..I would like to buy a high-quality kit...anyone?

Brett.

How's the hotspot without condenser (when the satinsnow groundglass is used)? The erecting version has a real issue with polished-back AO5 glass through a 7+ achromatic diopter.

<<<-- Originally posted by Obin Olson : Does anyone on this board have a Kit I can buy? I LOVE my 35 adaptor but the build quality is low..I would like to buy a high-quality kit...anyone? -->>>

i have a design i am about to finish..i have the thought of making it a kit...

take a look

http://www.dvinfo.net/conf/showthread.php?s=&threadid=27290&perpage=15&pagenumber=19

If you do, what sort of prices would we be talking about?

i think its best to talk about prices when the results come out...i still have to put the motor on ..but im coming to the end...i think ill finish it completly in one month the most...

Fair enough :)

Sounds great. Let us know when you finish. I'd love to see the results.

Hey all,

I want to get 35mm Depth of Field on my XL2. The EF adapter canon makes maginfies the focal lenth of the lenses by 7.8x (in 16:9 mode on the XL2) Which is not what I want.

Some of you are the experts on this stuff. Maybe you can answer my question: Why cant an adapter be made that can shrink the image created by the 35mm lens down to the size of the XL2's CCD's? I can understand the problems with fixed lens cameras and why you need to shoot the image off of a ground glass. But I dont understand why the image can't be optically shrunk and focused on the CCD's.

Thanks for your help!
Andre

I was recently interested in this very idea Amon. It won't work though. You can retain the FOV but not the DOF.

Just wanted to chime in and say Amon Tobin has some amazing tracks :)

Hmmm I definately want the Depth of Field. Check out this link:


http://www.enormousapparatus.com/35adapter.htm


Looks pretty awesome actually. I put the stills on my tv monitor to check for sharpness. Looks great! You get some blurring and darkness around the edges. And you can make out the ground glass too. Has anyone developed a better method then this?

That P+S teknic adapter is way overpriced. Im suprised no other company has created their own to undercut them.

amon.

yep. That would be a static adapter. The only problem with that form is that you will have grain from the ground glass.

The Agus (I believe?) uses a ground disk which is spun which keeps the grain from being visible.

Several people are working on oscillating gg version.

Ive been reading up on how to create my own.. But I guess im just amazed that no large company has attempted to mass produce a professional one like the P+S Teknik mini35 but far more affordable. Id be happy to spend a grand and have something that is solid and sharp. The mini35 is 7 grand or something? ridiculous!

amon