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  1. #11

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    Hi All

    thanks for the replays
    Sorry its been over a day since I posted !

    I'm trying to shoot really deep focus
    something like this



    the real footage is sharper than what is on vimeo
    but that lens is not available to me

    I have got it in my head that there are lenses that are optimised to shoot at tiny apertures

    Ralph you have a PM

    robin

  2. #12

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    Quote Originally Posted by rbrigham View Post
    Hi All

    thanks for the replays
    Sorry its been over a day since I posted !

    I'm trying to shoot really deep focus
    something like this



    the real footage is sharper than what is on vimeo
    but that lens is not available to me

    I have got it in my head that there are lenses that are optimised to shoot at tiny apertures

    Ralph you have a PM

    robin
    That really isn't possible. The diffraction limit can be approximated by dividing the f number into 1500, there really is no getting around it.

  3. #13

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    Sorry I can't add any technical knowledge to this discussion, macro 35mm motion picture work is not something I've ever done. But this is a big field that has been dealt with for years, there have been many specialty macro lens assemblies made for this type of work. Have you tried the local rental houses? Also a forum like cinematography.net (CML) or cinematography.com will have discussions and members with exactly the kind of knowledge and expertise you may be looking for. Good luck!

  4. #14

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    Robin, the moral of this story is that when you ask for advice on solving a problem you shouldn't present a solution, you should present the problem.

    A variety of deep focus lenses, all for cinematography, have been patented. None uses a tiny aperture to get the effect. The link you posted shows near and distant subjects more-or-less equally illuminated. This isn't possible in general with artificial illumination as would be required with the usual frame rates, capture media, and a tiny aperture. That should have been a tipoff that a tiny aperture isn't the solution.

    If you don't have much budget your choices come down to renting a proper deep focus lens or buying a split diopter. None of the effects in the video seem to have been achieved with a split diopter.

  5. #15

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    A GoPro with it's wide lens and tiny sensor draws sharp pretty much everything.

  6. #16

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    Quote Originally Posted by miha View Post
    A GoPro with it's wide lens and tiny sensor draws sharp pretty much everything.
    Due to the miniscule reproduction ratio, not a small f number.

  7. #17

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    Sure.

  8. #18

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    Hi Dan

    I think the moral of the story is not to ask questions that you might feel the need to answer
    can you advise on any subject that would be suitable for me to ask about

    I am well aware of lens systems such as the Frazier lens which can get an amazing result and I am well aware of the methods used to get there

    I was looking for something different hoping that somebody would say a Zeiss this or a Leitz that or whatever has a very good performance when stopped right down
    presumably a plastic holga lens will not perform as well as a Zeiss macro under these conditions
    it therefore follows that somewhere there is the best design for high stop deep focus work be it a tessar, planar or whatever or maybe just maybe something I don't know about

    I do not know what methods steve downer used to get the results in the video i posted I can guess but I don't know

    the reason I posted the question in the apug macro section was so that somebody who knows more than me might be able to advise me on my actual question
    not so that you can guess at my education

    and as for "Troll"

    maybe you should look up the definition and think about if it applies to you

    robin

  9. #19

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    Robin, I'm slightly acquainted with closeup photography and photomacrography. That's why I asked what magnifications you'd be working at.

    I'm slightly acquainted with high performance macro lenses from microscope manufacturers and merchant lens makers' microscopy divisions. I even have a few and sometimes use them. The only way to get any DoF at all at high magnification is to use confocal techniques, also called focus stacking. The conditions needed for this to work are stringent; the approach seems poorly suited to cinematography.

    I'm slightly acquainted with process lenses that stop down to tiny apertures, have some and use 'em, but never stopped 'way down. The loss of image quality isn't worth the gain.

    Ain't no magic bullets. The closest one can come to what you want on a budget is a split diopter. For cinema applications these are a little limiting, won't permit the pans shown in the video.

    Re loss of image quality on stopping down, here's an exercise for you: pick a magnification, calculate DoF for it given a circle of confusion that makes sense in your work and a range of effective apertures. Then calculate the diffraction limit given effective aperture. You'll find that there's a limiting aperture; stopping down beyond it will give a diffraction blur circle large than the circle of confusion. H. Lou Gibson published the calculations and pictures showing the effect in Kodak Publications N-12B Photomacrography and N-16 Close-up Photography and Photomacrography. They're scary books.

    Practically no one outside of Hollywood can afford the gear the studios use and, usually, rental houses own. That includes most, if not all, of the posters on this forum.

    Troll? Me? Nah, I don't post with the intention of getting strangers to fight. The word you want to use is curmudgeon.

  10. #20

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    Quote Originally Posted by rbrigham View Post
    Hi Dan

    I think the moral of the story is not to ask questions that you might feel the need to answer
    can you advise on any subject that would be suitable for me to ask about

    I am well aware of lens systems such as the Frazier lens which can get an amazing result and I am well aware of the methods used to get there

    I was looking for something different hoping that somebody would say a Zeiss this or a Leitz that or whatever has a very good performance when stopped right downpresumably a plastic holga lens will not perform as well as a Zeiss macro under these conditions
    it therefore follows that somewhere there is the best design for high stop deep focus work be it a tessar, planar or whatever or maybe just maybe something I don't know about

    I do not know what methods steve downer used to get the results in the video i posted I can guess but I don't know

    the reason I posted the question in the apug macro section was so that somebody who knows more than me might be able to advise me on my actual question
    not so that you can guess at my education

    and as for "Troll"

    maybe you should look up the definition and think about if it applies to you

    robin
    Unfortunately, all lenses from all manufacturers obey the same laws of physics.

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