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Thread: FS: focusing screens (GG) for 35mm adaper DIY projects

  1. #1
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    I have used Canon EE-A and EE-S and was unhappy with both of them for a number of reasons (ghosting, vignette, low sharpness near the edges, dirt prone), so I've ground myself a screen which I am happy with. Spent some time, gained some experience and can grind one for you.

    size: 38 x 25 mm (same as Canon EE)
    thickness: 1 mm (about 50% thinner than Canon EE)
    grain: a selection of four grades is available: 5, 9, 15, 25 micron (1000, 1200 grit are discontinued due to low diffusion rate)

    FAQ

    - Washable! Unlike canon (which is screwed if you touch it), you can clean this screen with warm water and soap. I was very frustrated to see my $40 getting wasted just because I touched this sucker.
    - will fit any holder designed for Canon EE, like these excellent holders manufactured by Daniel (thanks mate, you're the man)
    - no ghosting, sharper edges.
    - grain is still visible on finest, so I would recommend these screens for vibrating use.
    - please remember: this is just a ground glass, not a condenser lens like Canon EE. To compete with EE in terms of the light loss, you might need an extra lens in your adapter.

    New product: D1Pro

    The polished side of D1Pro is coated with multi-layered BBAR anti-reflective coating, giving it following benefits:
    - reduced back reflections; amount of light reflected by diffuser back to the lens is more than 10x less than uncoated version
    - improved light transmission, 5% more light passes through to the camera compared to uncoated version
    - reduced glare, greater clarity, sharper image.


    (Diffusers' polished side is facing camera against bright daylight window)

    Confused about which grain is best for you?
    Go for 9 micron if you're building a vibrating adapter; it provides good diffusion and natural bokeh.

    Some frame grabs I took with my adapter using these diffusers:




    These are raw frames (except B&W). Un-cropped, no color correction, straight from my HV20, pulldown removed.

    Footage:
    15 micron demo
    Older footage

    All framegrabs and footage were shot with D1 (uncoated) diffusers.

    Prices:
    D1 uncoated diffuser: $15
    35mm enthusiast special promo: three D1 diffusers for $39.95
    D1Pro diffuser with anti-reflective coating: $38.95

    Worldwide airmail shipping: $7
    Paypal payments.
    To order, please email your selection to alex.diffusers@gmail.com

    Need a custom sized or shaped gg?
    Got a glass/lens that needs grinding?
    Email me and we'll think something out!

    I'm also taking orders for building a complete adapter for your HV20.


    [this post is updated regularly, so check back once in a while]
    Last edited by Alex_MD; 2008 November 17th at 17:56.

  2. #2
    Legend Ian-T's Avatar
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    Dang....you were not kidding!!! Sharp as a tack!!!
    "Great spirits have always encountered violent opposition from mediocre minds" ...Albert Einstein

  3. #3
    Super Member Kyleman's Avatar
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    Yeah, Very nice.

  4. #4
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    Can we see some moving pictures with this adapter?
    "Great spirits have always encountered violent opposition from mediocre minds" ...Albert Einstein

  5. #5
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    Sure thing. Will post tomorrow.
    35mm enthusiast. my Vimeo profile
    Looking for some ground glass? Ask me.

  6. #6
    Senior Member sirjoe's Avatar
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    very interested !

  7. #7
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    How do your focusing screens get rid of vignetting or light loss at the edges? Are you using a condensor?

    Sounds interesting!

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    Great! Alex, I have just watched footages in your Vimeo channel. Is that footages shot using your self-made screen?

  9. #9
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    Hi guys, thanks for the interest.
    Ian, those old clips on Vimeo were shot with Canon screen. I was happy with it until I went shooting snowy scenes and got a tremendous amount of aberrations and ghosting.. a result of a fresnel I guess, I never see this on my screens.
    kmwf, yes I do have an extra condensor in my adapter. Wihout it, image is *VERY* crisp but hotspot is a little bit too much for my liking

    I will try to upload some footage today. Stay tuned
    35mm enthusiast. my Vimeo profile
    Looking for some ground glass? Ask me.

  10. #10
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    So does your self-ground ground glass come with the condensor or would I have to get one somehow?

    Thanks again,
    Peter

  11. #11
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    @Alex_MD, tell me about your condenser!
    Sharp Shooter

  12. #12
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    Some footage, shot this morning with 9 micron diffuser
    http://vimeo.com/846225
    35mm enthusiast. my Vimeo profile
    Looking for some ground glass? Ask me.

  13. #13
    Legend Ian-T's Avatar
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    I don't know about the rest of you guys...but that has to be the cleanest, brightest and sharpest footage from DIY DOF adapter I've seen. Alex...what type of condesner do you use? I use my adapter with a 10+ macro...would that be enough?

    It's even sharp watching it on Vimeo....I still have not downloaded the video.....very nice.
    "Great spirits have always encountered violent opposition from mediocre minds" ...Albert Einstein

  14. #14
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    Thanks dude. I guess it's achromat you're talking about..
    condenser is basically the same lens but placed in front of the diffuser to increase the hotspot
    The one I've got is a front glass of an old binocular. I pulled it out of pile of rubbish.

    I rendered 720p for faster upload.
    Last edited by Alex_MD; 2008 April 5th at 21:02.
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  15. #15
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    Quote Originally Posted by Alex_MD View Post
    Some footage, shot this morning with 9 micron diffuser
    http://vimeo.com/846225
    Nice footage! Was this footage shot on the HV20? Did you shoot in Cine or Tv mode?

    Did you using a static or vibrating adapter to shoot this footage?

    Some questions about the GG:

    Does your custom-made gg include the condensor? If not, what size does the condensor need to be, where would you get one, and how do you mount it or attach it to the ground glass?

    grain: 5, 9, 15, 25 micron; 1000, 1200 grit.
    Are the grain sizes you mention choices we can pick or the different types of grain you use to grind the glass?

    Is the glass sanded, blasted, or another method?

    Sorry for all the questions At $15 USD, it sounds like a steal but if I also need to find a condensor to get rid of the hotspot, it may be comparable to buying a Canon EE-series focusing screen without the additional hassle of having to go dumpster diving to have to find an old pair of binoculars... LOL

    Thanks! The footage looks great!
    Peter

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    Very nice, Alex! Can I order now?

  17. #17
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    wow pretty intense stuff mate

  18. #18
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    - grain is still visible on finest, so I would recommend these screens for vibrating use.
    I'm interested in one, but is there any way to see a sample of the different grain sizes? Also, I'm assuming your footage is with a vibrating adapter, any chance of you showing what the GG looks like when it's NOT vibrating?

    Thanks

  19. #19
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    Peter,
    Yeah I'm shooting with HV20, shutter priority 1/48, vibration ON.
    You can pick from any of the six grades I listed.
    I don't sell condensers and don't have a complete and perfect solution, I'm still searching... surplushed.com has loads of lenses real cheap, I believe any condenser (plano- double- or bi-convex) of appropriate size will do the job, just make sure it fits inside your adapter and covers the visible area of your screen.

    david
    I will search for the frame with vibration OFF to show you how 9 micron looks like when static.
    Last edited by Alex_MD; 2008 April 1st at 06:44.
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  20. #20
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    Quote Originally Posted by Alex_MD View Post
    I believe any condenser (plano- double- or bi-convex) of appropriate size will do the job, just make sure it fits inside your adapter and covers the visible area of your screen.
    Really? Can anyone else verify this? I would think the different types of lenses have different properties and introduce different types of distortions (or corrections, in this case).

    I think, traditionally, people use a plano-convex lens to avoid vignetting.

    What did you use to hold your ground glass and condenser assembly? How did you attach or mount the condenser? Which vibrating GG holder do you use or is it also something you custom made?

    Thanks again,
    Peter

  21. #21
    Senior Member ForwardLooker's Avatar
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    wow Alex this looks great!! well done..I'm glad someone has taken the time to come up with a different solution other than the canon screens. As much as i love my Ee-s it isn't perfect and your footage looks great!! i'll email you soon.
    Just wondering if you could put a comparison of the different grits you have?

  22. #22
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    Peter I think you're right, too long focal length would probably be not enough to get rid of the hotspot and too short FL would produce a distortion. didn't have a chance to check this though. my condenser FL measures about 10cm.

    ForwardLooker, I guess I can manage that... but it will take some time, as I will have to change diffusers a lot.

    By the way: has anyone expirienced excessive aberrations on EES screen? Could you post the frame?
    35mm enthusiast. my Vimeo profile
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  23. #23
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    Hi Alex - the footage looks amazing! best I've seen so far without a doubt

    deleted questions...

    Edit: Sorry - didn't realize this wasn't in the DIY forum and was in the "For Sale" forum - probalby not appropriate to ask the How to's - sorry
    Last edited by GeeksGoneBad; 2008 April 1st at 09:45.
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  24. #24
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    I've uploaded a static vs. vibrating test with various F-stops.
    http://vimeo.com/850290
    For some reason Vimeo converts my 1080p into 4:3, so I had to upload in 720p. Sorry.
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  25. #25
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    Alex,

    Just an idea, have you tried grinding the plano side of your condenser to make a condenser/ground glass built into one piece? It would get rid of any dust getting in between the condenser and ground glass and I would imagine, would make mounting it easier

    Peter

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