More Macro Madness

Discussion in 'Digital SLR' started by Paul Furman, Oct 11, 2009.

  1. Paul Furman

    Paul Furman Guest

    Paul Furman, Oct 11, 2009
    #1
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  2. Paul Furman

    BobS Guest

    Jeeeezusssss - Don't you ever clean your pens......;-)

    That is really shallow DOF - wow !

    Bob S.
     
    BobS, Oct 11, 2009
    #2
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  3. Paul Furman

    Paul Furman Guest

    I already showed you how DSLRs are perfectly capable of stopping down
    and how there's a price to pay, in our last lesson, but I'll make it
    easier with a pair of crops.

    Crops side by side:
    http://www.flickr.com/photos/edgehill/4001765670/sizes/o/in/set-72157603231101723/


    Originals:

    Shallow DOF at f/16, notice the web-like hairs:
    http://www.flickr.com/photos/edgehill/3965216782/sizes/l/in/set-72157622353514479/

    Stopped down to f/90 lacks detail:
    http://www.flickr.com/photos/edgehill/3964444445/sizes/l/in/set-72157622353514479/
    --
    Paul Furman
    www.edgehill.net
    www.baynatives.com

    all google groups messages filtered due to spam
     
    Paul Furman, Oct 11, 2009
    #3
  4. Paul Furman

    Paul Furman Guest

    Yeah, though it's the nature of extreme closeup work if you remember
    using a microscope in school. A better lens would probably help too. The
    other example crops are a 105 macro lens but the 2x teleconverter
    stretches it's abilities, butchering the bokeh and this is stretched
    wayyyy beyond intended use as well, the 50mm lens has a closest focus of
    only 2 feet. The beauty of this setup is it's compact & no tripod
    needed. If I put the big 105 on the bellows and a tripod it would be
    very unwieldy. That's why they make bellows lenses.

    Yes, though it gets soft all over:
    http://www.flickr.com/photos/edgehill/4001077917/sizes/o/
    -that's f/22 on the 50mm lens, the other was f/8, hard to tell much in
    this case, see the crop examples in my other reply for a more extreme
    comparison with true f/numbers. The bellows changes effective aperture,
    here's a formula for the bellows extension:
    http://olyflyer.blogspot.com/2007/06/calculation-of-effective-aperture-in.html

    So f/8 is f/32 and f/22 is f/88 assuming the reversed lens on front
    has no effect which I think is true. If I stop down the front lens, it
    vignettes severely.

    Wow, so wide open at f/1.8 would be f/7.2 and f/4 is really f/16.

    focal length plus extension times f/number divided by focal length

    Nikon Series-E 'pancake'(reaches 8:1 with reversed 35)
    (50+150mm) * f/1.8 / 50mm = f/7.2
    (50+150mm) * f/2 / 50mm = f/8
    (50+150mm) * f/4 / 50mm = f/16
    (50+150mm) * f/8 / 50mm = f/32
    (50+150mm) * f/22 / 50mm = f/88

    Spiratone macrotar (reaches 5:1 alone)
    (35+150mm) * f/3.5 / 35mm = f/18.5
    (35+150mm) * f/4 / 35mm = f/21
    (35+150mm) * f/8 / 35mm = f/42
    (35+150mm) * f/16 / 35mm = f/84

    El-Nikkor (reaches 7:1 with reversed 35)
    (80+150mm) * f/5.6 / 80mm = f/16
    (80+150mm) * f/8 / 80mm = f/23 <- optimal
    (80+150mm) * f/16 / 80mm = f/46
    (80+150mm) * f/32 / 80mm = f/92


    --
    Paul Furman
    www.edgehill.net
    www.baynatives.com

    all google groups messages filtered due to spam
     
    Paul Furman, Oct 11, 2009
    #4
  5. Paul Furman

    Richard Guest

    OK. I asked you before how you would do stuff like this. Paul replied with a
    whole bunch of informative stuff. From you... nothing. Are you going to come
    up with something constructive or what?

    Thank you.
     
    Richard, Oct 11, 2009
    #5
  6. Paul Furman

    Paul Furman Guest

    I haven't tried software, sometimes manually patching together:
    http://www.flickr.com/photos/edgehill/3964446143/sizes/l/in/set-72157622353514479/

    Ack, I'm going to need to look into that, I just tried an old projector
    lens in front of the 80, the best results yet... which means it really
    is better a little wider like f/8 which is f/23 if you figure extension.
    http://www.flickr.com/photos/edgehill/4003179860/sizes/o/in/set-72157622433752649/

    --
    Paul Furman
    www.edgehill.net
    www.baynatives.com

    all google groups messages filtered due to spam
     
    Paul Furman, Oct 12, 2009
    #6
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