Re: Shoot Macro on 8x10 like Karl Blossfeldt
Place your subjects on a very stable platform that can me smoothly raised during exposure and pass light through extremely narrow slits at 90 degree angles from the plane of focus. Shoot at optimal aperture for the magnification. Raise the subject through the slits of light at appropriate speed for correct exposure. Laser levels would be easier to implement but the color would work effectively as a very narrow band pass filter. I can't remember what this procedure is called.
Re: Shoot Macro on 8x10 like Karl Blossfeldt
Quote:
Originally Posted by
consummate_fritterer
Place your subjects on a very stable platform that can me smoothly raised during exposure and pass light through extremely narrow slits at 90 degree angles from the plane of focus. Shoot at optimal aperture for the magnification. Raise the subject through the slits of light at appropriate speed for correct exposure. Laser levels would be easier to implement but the color would work effectively as a very narrow band pass filter. I can't remember what this procedure is called.
Deep field (scanning) photomacrography, technique first developed by Nile Root when he taught at RIT. Later called Scanning Light Photomicrography and written up by William Sharp and Charles Kazilek.
Re: Shoot Macro on 8x10 like Karl Blossfeldt
Shiitake Macro 3-1, f64, Sironar N MC 360 mm. Scan V700 of 11X14 X-Ray Kodak CSG cropped to 8X8" Bellows about 45" Deardorff S11. Strobes. Contact printed after the scan for the Internet.
Just another experiment. The 11X14 S11 has 72" of extension and can shoot at any angle.
I really got to get it setup again even if the studio floor falls in...:)
https://farm8.staticflickr.com/7326/...745b3346_b.jpgShitake 3-1 8X8 scan of 11X14 X-Ray by TIN CAN COLLEGE, on Flickr
Re: Shoot Macro on 8x10 like Karl Blossfeldt
Quote:
Originally Posted by
Greg
Deep field (scanning) photomacrography, technique first developed by Nile Root when he taught at RIT. Later called Scanning Light Photomicrography and written up by William Sharp and Charles Kazilek.
I 'invented' this process when I was fifteen years old, only to discover it was patented a year before I was born. Always "a day late and a dollar short".
Re: Shoot Macro on 8x10 like Karl Blossfeldt
Quote:
Originally Posted by
Dan Fromm
Luke, if Blossfeldt shot at 30:1 with one meter of extension he had to have used quite a short lens.
Dan, thank you for your comment regarding diffraction. So, this evening I got around to reading the PDF that Luke linked to above. It's quite interesting in general, but the meat of it for the purpose of this discussion is this: The author indicates that Blossfeldt used a 500mm Aplanat 1:36, and that he had bellows of approx. 1 meter long. Exposure times ranged from 8-12 minutes (no surprise there!). Does this even make sense? A 500mm lens would need 1 meter of bellows just to do 1:1. That's a far cry from the 20:1 or 30:1 magnification exhibited in his prints. Can you or anybody else help make some sense of this? Dan, your comment about a shorter lens resonates with me (and is supported by the basic math) because when I've done close-up work with my 4x5 and run out of bellows, I reach for a shorter focal length lens.
Re: Shoot Macro on 8x10 like Karl Blossfeldt
Re: Shoot Macro on 8x10 like Karl Blossfeldt
Randy, he did enlarge as far as I can glean from what's been written. But a negative taken at 1:1 does not yield the detail of 1:30 magnification through enlargement. Still contemplating how to go about this - and I still believe it's going to be a rather simple affair.
Re: Shoot Macro on 8x10 like Karl Blossfeldt
I have made several experimental images of this type - usually of dead flowers. Most of these have been made with a 135mm but I am getting ready to try a movie lens designed for 16 mm cameras. I believe it should work well on my 5x7 Deardorff, as well as the Wehman 8x10. I will begin with it positioned in normal manner, and then the same images with the lens reversed. I believe wide open will work best as stopping these small lenses down is likely to introduce diffraction. If I had a lens designed for 35mm movies I certainly would use it.
Yes, he did enlarge his negatives which I strongly suspect were glass plates which produce sharper enlargements than film negatives. I probably will not use glass negatives even though I do have the equipment to do so.
I normally use single sided X-ray film for such images and will do so with these new experiments.
Re: Shoot Macro on 8x10 like Karl Blossfeldt
Jim, the killer is magnification. Makes the effective aperture smaller than the nominal aperture set.
When I was testing lenses for work above 1:1 I found that the really good ones, e.g., Luminar, MacroNikkor, were best wide open, lost central resolution when stopped down at all. This wasn't quite true for a 25/1.9 Cine Ektar II. Superlative around 15:1, but better at f/2.8 than at f/1.9. Below f/2.8, the mush just got worse. Similar results for a reversed 55/2.8 MicroNikkor AIS. Best at f/4, central resolution was worse at smaller stops.
Re: Shoot Macro on 8x10 like Karl Blossfeldt
Not that he needs any help from me, but my experience matches Dan's.