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06/14/2004 12:15:13 AM · #1 |
Here is a photo of the hardware setup I used to produce 'Sacajawea'. The method needs a lot of work before I will be able to produce quality photos,
but I think it is worthwhile pursueing. The biggest problem is control of light balance between the foreground and background subjects. Any suggestions for improvement are welcome!
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06/14/2004 12:41:41 PM · #2 |
Any comments or suggestions?
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06/14/2004 01:42:05 PM · #3 |
This is a very curious technique. The results were certainly very impressive, technically, although as you say, not very aesthetically pleasing, and thus didn't do as well as I thought they should have.
Did you read this technique somewhere? Do you have any examples of it "done perfectly"? Or are you learning it as you go?
-Will
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06/14/2004 01:48:56 PM · #4 |
That's an incredible setup! I appreciated such technicalities, expecially considering I'm in physics and optics is my favorite subject. Did you figure out the distances empirically or theoretically first?
Too bad your picture isn't aesthetically pleasing. Did you try any other subjects with the same setup? |
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06/14/2004 04:06:29 PM · #5 |
Originally posted by labuda:
That's an incredible setup! I appreciated such technicalities, expecially considering I'm in physics and optics is my favorite subject. Did you figure out the distances empirically or theoretically first?
Too bad your picture isn't aesthetically pleasing. Did you try any other subjects with the same setup? |
text
The focal plane of the large lens was determined by using a ground glass imaging screen. Turned out to be exactly 8 inches from the the housing of the lens. Any camera will image the virtual image of a lens if focused to that plane.
The field of view of the camera in macro mode is satisfactory to capture that virtual image. Then a foreground subject must be centered in the focal plane and positioned laterally so that the background image is not completely obscured.
I used manual focus mode on the camera because the background scene had low contrast and auto focus was not adequate. Light balance is the biggest problem. Even with an f/3 focal ratio, the background was not as bright the foreground subject.
My limited skills otherwise contributed largely to the poor quality of the image entered in DOF. I have since produced some higher quality images but still need improvement. I believe that a shroud over the focal plane would help so that stray light would have less effect on the image contrast.
The foreground subject could be illuminated independently using a portable light source. This light source would have to be shielded from the forward lens to avoid reflections from that lens.
Altogether, the apparatus has very limited usefulness, so unless you have parts available at low cost, it is not worth the expense. Salvage lenses from photo-copy machines or old TV projection systems might work well.
My background is primarily physics with a substantial involvement in optical systems. I was employed at Sandia National Laboratories for 27 years as a Senior Technical Advisor. I retired 2 years ago.
If anyone wants further info on this system or the one I used for the Habits Challenge, "JAVA", PM me!
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