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Thread: 4x5 Ultra Fine Focusing and Calibration

  1. #1

    Join Date
    Apr 2006
    Posts
    135

    4x5 Ultra Fine Focusing and Calibration

    For Sale:

    Loupe and Stands for 4x5 Precision Plenum Photography

    Focusing with GG (Ground Glass) is crude and inaccurate.

    Offered here is a shimmed plenum and loupe that allows you to verify
    that your emulsion plane and focal plane are aligned within .001"
    by bringing both into focus simultaneously.

    This allows the photographer to validate the camera system and
    evaluate details that would not be possible otherwise.

    Get the kind of resolution out of your equipment that would make Ansel
    Adams cry. Isolate problems, calibrate and utilize equipment at the
    highest possible level of performance.

    With advances in sheet film scanning (the betterscanning.com fluid
    scan film holder of one) you can create high quality 4x5 images that rival
    several hundred dollar fluid drum scans.

    Using GG is great for composition but almost useless for finely
    focused precision photography. Create images reliably and consistantly
    that fully exploits the 3200dpi fluid scan resolution with breathtaking
    results.

    To use the plenum and loupe simply remove the Ground Glass holder.
    Once Focused remove the plenum, re-insert the GG and Film Holder
    (or 120/220 back) and take the picture.

    Satisfaction Guaranteed or Money Back (less shipping)

    Pricing Includes Full Documentation and Support

    DIY fabrication of the glass and shimming it to the critical dimension.

    For normal to near telephoto lenses:
    $79.95 for the Loupe (default center of frame stand).

    For Wide Angle Angle:
    $119 for Loupe and side (of 4x5 frame) stand

    $149 for Loupe, side and corner (of 4x5 frame) stand

    Ready to go tested shimmed plenums

    $49.95 For Glass

    $49.95 For Acrylic

    Tools for lp/mm Lens Measurement and Profiling
    $79.95 for Microscope with Reticule and CS Target.

    Transactions will be conducted via ebay and paypal.
    Search for "Fine Focusing Loupe" for example listings.
    Let me know you saw it here so we can customize your kit.

    Shipping is $10, $20 for 4x5 plenums and $30 for 8x10 plenums

    Comming soon
    $349 4x5 kit with everything for the serious LF photographer
    $449 8x10 kit with everything + corner stand (builds on the 4x5 kit)
    8x10 plenums are glass only

    Still in development
    $149 Precision Film Holder (+/- .0005" aligned emulsion plane), USB Black Bag Camera, Documentation and Support

    $249 Precision Film Holder (+/- .0005" aligned emulsion plane), Darkroom Night Vision Documentation and Support

    $Not Priced yet - Universal upgrade to CCD fluid scanning systems

  2. #2
    Just waiting to be developed..
    Join Date
    Feb 2007
    Location
    New Rochelle, NY 10804
    Posts
    502

    Re: FS 4x5 Ultra Fine Focusing and Calibration

    This is very interesting. I would like some more information.
    Would you have any pictures or a website you can post?
    I found this on ebay, is this what i would be purchasing?

    Thanks
    -Ian Mazursky
    www.ianmazursky.com Travel, Landscape, Portraits and my 12x20 diary
    PrePress Express

  3. #3

    Join Date
    Jul 2007
    Location
    Austin TX
    Posts
    2,052

    Re: FS 4x5 Ultra Fine Focusing and Calibration

    Ian, this is a somewhat confusing post. But yes I think what he is selling is a classic focusing telescope with a calibrated reticle within the eyepiece. The magnification factor of the telescope is so high it would require viewing an aerial image only. The second part is, I think, a film holder with a clear screen but perhaps some small fiducials on the side closest to the lens. One focuses the telescope (high power loupe) on the fiducials to capture the equivalent film plane then one focuses the LF lens at the same plane. Now both fiducial and image are exactly parfocal. Next, assuming the film holder is exactly the same design as the test holder (.191 inch depth from the holder stops; or whatever) one will have captured the exact focus plane with the film holder (minus variations in the film flatness of course, which can be significant).

    Perhaps the seller can confirm my interpretation as well as yours.

    Nate Potter, Austin TX.

  4. #4

    Join Date
    Nov 2005
    Location
    Rondo, Missouri
    Posts
    1,929

    Re: FS 4x5 Ultra Fine Focusing and Calibration

    Either way, I think it's a violation of forum rules to point to an ebay listing or store in a FS or FT listing here.
    Michael W. Graves
    Michael's Pub

    If it ain't broke....don't fix it!

  5. #5

    Join Date
    Apr 2006
    Posts
    135

    Re: FS 4x5 Ultra Fine Focusing and Calibration

    I'm afraid you could be right in some small sense, so someone needs to ask site admin for clarification and perhaps suggestions on how one might communicate facts gracefully without violating forum rules (and/or their intent).

    We also need a judgment on if the "Critical Mission" nature of the site over rides mindless strict interpretation of its rules. In my providing carefully engineered solutions and techniques to show that film is still superior to digital (and its global marketing machine) I have hopefully served the greater good.

    I was hoping to be up front as to how the for sale goods are transacted (on that big nasty auction site and its escrow mini-me who I really do not like - at all).

    My guess is an using an URL is generally bad practice, but mention of a site would be ok as long as it has content with honest intellectual and LF forum value (as opposed to cross-posted spam messages we get in our email every day) and that this finding is recognized by members and moderators in general.

    As another example, technically I've probably violated that URL concept (along with a
    few other members) for yet another compelling LARGE FORMAT FORUM charter driven reason. We did point to a fluid film scanning product that has solved 90% of the problems with holding 4x5 film flat and Newton's rings on flat bed scanners. I've lost hundreds of hours to that problem, multiplied that by other film scanning LF members means it has likely been a HUGE problem in urgent need of a solution to many.

    Furthermore I would like to scientifically prove here that film will be superior to digital for the rest of our lives given TWO things.

    1.) We can scan LF film at its maximum resolution by holding it near perfectly flat
    WITHOUT Newton's rings (hence the critical reference to the betterscanning.com
    4x5 fluid scan holder - there you made me do it again)

    2.) USING THE SAME TANGO DRUM SCAN FLUID MOUNTING TECHNIQUE (which can cost $300 for ONE full resolution 4x5 scan) to hold the unexposed film perfectly flat
    (to +/- .0005") and have the emulsion plane within better that +/- .001" of the finely precision focused image (that pesky 4x5 plenum photography and loupe again - which is actually a microscope available with 90 degree, 75 degree and 65 degree stands for 4x5 wide angle lenses, one can get by with just 90 degree stand for a normal to near telephoto lens).

    This far exceeds the repeatable capabilities of ground glass and as such is worthy of telegraphing this information (about the loupe with plenum kit and fluid scanning holder) to forum members, many who have already invested thousands into their equipment and never actually seen what it is really capable of doing and should
    be able to do so at will and on a daily basis (another purpose of the forum I would
    suppose).

    So, is this forum a safe harbor for all things large format ? Or is this forum here so that the strictest interpretation on rules can trump all things Large Format ?

    I guess we will find out. In the mean time I've got about a preview of about 60 pages of documentation, drawings and pictures that needs to go out to those who are
    interested in more information. I know people embed URLs to pictures on the site
    legally so I need to learn how to do that when time permits.

    Cheers !

    Richard

  6. #6

    Join Date
    Apr 2006
    Posts
    135

    Re: FS 4x5 Ultra Fine Focusing and Calibration

    Greetings Nate !

    Quote Originally Posted by Nathan Potter View Post
    Ian, this is a somewhat confusing post. But yes I think what he is selling is a classic focusing telescope with a calibrated reticle within the eyepiece. The magnification factor of the telescope is so high it would require viewing an aerial image only.
    I'm replacing the 100x microscope with components that are of much more value
    the the LF work flow everyone wants.

    Quote Originally Posted by Nathan Potter View Post
    The second part is, I think, a film holder with a clear screen but perhaps some small fiducials on the side closest to the lens. One focuses the telescope (high power loupe) on the fiducials to capture the equivalent film plane then one focuses the LF lens at the same plane.
    I use a clear glass or acrylic plenum that has been shimmed to the "critical dimension"
    of .190". Not only do you get mind numbing sharpness (across the entire frame) but
    the film emulsion plane can be brought into sharp focus simultaneously. AN involuntary
    WOW!!! comes out every time I see it.

    Quote Originally Posted by Nathan Potter View Post
    Now both fiducial and image are exactly parfocal. Next, assuming the film holder is exactly the same design as the test holder (.191 inch depth from the holder stops; or whatever) one will have captured the exact focus plane with the film holder (minus variations in the film flatness of course, which can be significant).
    EXACTLY !!! And yes, out of the box film flatness is our worst enemy. I have a solution and its status is mentioned in another post in this thread.

    Quote Originally Posted by Nathan Potter View Post
    Perhaps the seller can confirm my interpretation as well as yours.
    Not only are we on the same page, but we are both using big-o-loupes !!!

    I'm not sure about the use of all the fiducials (both shims and ideally perfect
    aligned planes) but after I post some pictures (will need to learn how and
    see if they will let me) it should be much clearer.,.

    All the best,

    Richard

  7. #7

    Join Date
    Apr 2006
    Posts
    135

    Re: FS 4x5 Ultra Fine Focusing and Calibration

    > This is very interesting. I would like some more information.

    Would it be ok to send the preview information to ianmazursky.com ? I don't want to be spamming anyone by accident and I'm not sure yet about forum protocol.

    > Would you have any pictures or a website you can post?

    I do have a pile of pictures and I'll post some as soon as I figure out how and if the
    site admin will let me. I'm a old LF guy but using this site is new to me.

    > I found this on ebay, is this what i would be purchasing?

    Thats an old entry level listing that I should delete since there is a much better kit offered now. For the professionals I've recently decided to recommend a kit that
    (1.) Provides Mind-Blowing Focus across the entire frame (got that down).
    (2.) Provides a way to expose film in perfect alignment (got that down).
    (3.) Hold film so flat it as a mirror like reflection with no distortion when inspecting
    the holder. Currently the problem is not the holders, even though a vacuum back
    cannot achieve what I want. Its the out of the box film curl that is killing us. Even
    the cheap graflex holders can hold the film at +/- .001" of where we need it. I have
    a solution, it uses the same taping technique as with the drum scanner. I just need
    time to prototype and fabricate a one glass septum holder and test the useage of
    a black bag USB camera and/or night vision IR headset in the dark room.
    4.) For those of us who do not own a drum scanner, away to do a 4x5 fluid scan on
    a flat bed up to 3200dpi with film perfectly flat without newton's rings, thank you
    very much betterscanning.com)

    So thats it. Every LF Photographer should be able to snap and digitize a 4x5 piece
    film so sharp that the end product (500MB Tiff file) would make Ansel Adams cry.

  8. #8

    Join Date
    Apr 2006
    Posts
    135

    Re: FS 4x5 Ultra Fine Focusing and Calibration

    Quote Originally Posted by Michael Graves View Post
    Either way, I think it's a violation of forum rules to point to an ebay listing or store in a FS or FT listing here.
    I'm afraid you could be right in some small sense, so someone needs to ask site admin for clarification and perhaps suggestions on how one might communicate facts gracefully without violating forum rules (and/or their intent).

    We also need a judgment on if the "Critical Mission" nature of the site over rides mindless strict interpretation of its rules. In my providing carefully engineered solutions and techniques to show that film is still superior to digital (and its global marketing machine) I have hopefully served the greater good.

    I was hoping to be up front as to how the for sale goods are transacted (on that big nasty auction site and its escrow mini-me who I really do not like - at all).

    My guess is an using an URL is generally bad practice, but mention of a site would be ok as long as it has content with honest intellectual and LF forum value (as opposed to cross-posted spam messages we get in our email every day) and that this finding is recognized by members and moderators in general.

    As another example, technically I've probably violated that URL concept (along with a
    few other members) for yet another compelling LARGE FORMAT FORUM charter driven reason. We did point to a fluid film scanning product that has solved 90% of the problems with holding 4x5 film flat and Newton's rings on flat bed scanners. I've lost hundreds of hours to that problem, multiplied that by other film scanning LF members means it has likely been a HUGE problem in urgent need of a solution to many.

    Furthermore I would like to scientifically prove here that film will be superior to digital for the rest of our lives given TWO things.

    1.) We can scan LF film at its maximum resolution by holding it near perfectly flat
    WITHOUT Newton's rings (hence the critical reference to the betterscanning.com
    4x5 fluid scan holder - there you made me do it again)

    2.) USING THE SAME TANGO DRUM SCAN FLUID MOUNTING TECHNIQUE (which can cost $300 for ONE full resolution 4x5 scan) to hold the unexposed film perfectly flat
    (to +/- .0005") and have the emulsion plane within better that +/- .001" of the finely precision focused image (that pesky 4x5 plenum photography and loupe again - which is actually a microscope available with 90 degree, 75 degree and 65 degree stands for 4x5 wide angle lenses, one can get by with just 90 degree stand for a normal to near telephoto lens).

    This far exceeds the repeatable capabilities of ground glass and as such is worthy of telegraphing this information (about the loupe with plenum kit and fluid scanning holder) to forum members, many who have already invested thousands into their equipment and never actually seen what it is really capable of doing and should
    be able to do so at will and on a daily basis (another purpose of the forum I would
    suppose).

    So, is this forum a safe harbor for all things large format ? Or is this forum here so that the strictest interpretation on rules can trump all things Large Format ?

    I guess we will find out. In the mean time I've got about a preview of about 60 pages of documentation, drawings and pictures that needs to go out to those who are
    interested in more information. I know people embed URLs to pictures on the site
    legally so I need to learn how to do that when time permits.

    Cheers !

    Richard

  9. #9

    Join Date
    Apr 2006
    Posts
    135

    Re: FS 4x5 Ultra Fine Focusing Sheet Film Preview

    These are the first four pages of the sheet film document.

    Out of the box sheet film curl is the biggest contributor to
    softness. New Tools are to be tested soon so that near
    perfect film flatness can be obtained prior to exposure.
    Last edited by Ralph Barker; 23-Dec-2008 at 17:35.

  10. #10

    Join Date
    Apr 2006
    Posts
    135

    Re: FS 4x5 Ultra Fine Focusing Stands Preview

    This is the Preview for the Loupe Stands on the 4x5
    For a normal to near telephoto the 90 degree stand will do
    For Wide Angle three stands are required for full frame coverage
    90 degree for center of frame
    75 degree for middle to side of frame
    65 degree for corner of the frame

    Note that full frame coverage for a wide angle 8x10 will use the
    above stands plus one more for the corner.

    Each stand has an arrow center line to be pointed at the center
    of the lens aperture.
    Last edited by Ralph Barker; 23-Dec-2008 at 17:35.

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