Andrea B. Posted July 9, 2017 Share Posted July 9, 2017 Can you figure out what kind of filter was used to make each photo? Added: This is just for fun. I had absolutely no idea what these photos would show before I made them. Well, not exactly "no idea", but more like "only a vague idea". All photos were made using a D610-conversion + 105/4.5 UV-Nikkor + Filter.Exposures were made at f/5.6 and ISO-100 for an exposure time long enough to push the brightness histogram to the right without hitting the wall. The filter choices are:IR onlyUV onlyUV + IRUV + VisUV + Vis + IR -- Actually, this is an unfiltered shot. No lens filter was used, only the clear filter inside the D610 conversion.Vis onlyThese photos are shown in monochrome.I'll post the false color raw composites in the next post. The standards are displayed in a pressed cardboard box.Thus, the more experienced viewers may be able to use this background to figure out some of the filters. In an expanded browser, these 300 pixel wide photo should appear in two rows of 3 each.From left to right the filenames consist of letters only, which you will see if you hover your cursor over each photo.A B CD E F Link to comment
Andrea B. Posted July 9, 2017 Author Share Posted July 9, 2017 The raw composite colours will definitely give major clues (for some of you) to the identities of the filters. :D These raw composites were made in Raw Digger. A raw composite has been demosaiced but has had no white balance applied to the raw data. However, in the process of conversion to JPGs, an sRGB colour space is assigned so that the monitor and browser know how to display the photos. In an expanded browser, these 300 pixel wide photo should appear in two rows of 3 each.From left to right the files are named with double letters, which you will see if you hover your cursor over each photo.AA BB CCDD EE FF Link to comment
Hornblende Posted July 9, 2017 Share Posted July 9, 2017 Lets try: A: UV + VIS + IRB: VISC: UV + VISD: IR + UVE: IRF: UV Link to comment
OlDoinyo Posted July 10, 2017 Share Posted July 10, 2017 I will agree that E is probably IR and F is most likely UV. C contains UV and the box is dark in color, so UV+VIS might be a good guess. The black and dark grey standards give no diagnostic information at all; the three pale standards contain some info but not a great deal. B and D have the next darkest renditions of the box, with two of the pale standards slightly darker in B; thus I guess that D might be UV+IR and B might be straight VIS. That leaves A as the blank shot. Link to comment
Andrea B. Posted July 10, 2017 Author Share Posted July 10, 2017 Doesn't anyone else want to hazard a guess? It's just for fun. I'm prepping the raw composites now and should have them posted later today. Link to comment
Andrea B. Posted July 10, 2017 Author Share Posted July 10, 2017 So far we have: A. unfiltered, unfiltered, irB. vis, vis, visC. uv+vis, uv+vis, uv+visD. uv+ir, uv+ir, unfilteredE. ir, ir, uv+irF. uv, uv, uv (One person sent me a guess not posted here.) Now that the raw composites are up, would you revise your guess? Link to comment
Andrea B. Posted July 10, 2017 Author Share Posted July 10, 2017 A and E have the brighest backgrounds and are most nearly alike.Here are A, E and the Difference between the two frames. C and F have the darkest backgrounds and are most nearly alike.Here are C, F and the Difference between the two frames. B and D have the (remaining) matching backgrounds and are most nearly alike.Here are B, D and the Difference between the two frames. Link to comment
Andrea B. Posted July 10, 2017 Author Share Posted July 10, 2017 A = Infrared Only = Schott RG850 Top Left: Monochrome Top Right: Raw CompositeBottom: White-balanced Final Version One person got this correct. Link to comment
Andrea B. Posted July 10, 2017 Author Share Posted July 10, 2017 B = Unfiltered = UV+Vis+IRAlthough mostly IR is recorded, then some Vis. UV?? Hard to say, depends on the subject. Top Left: Monochrome Top Right: Raw CompositeBottom: White-balanced Final Version Nobody got this one correct. Link to comment
Andrea B. Posted July 10, 2017 Author Share Posted July 10, 2017 C = UV + Vis = BugU3Some visible blue and green are passed. Top Left: Monochrome Top Right: Raw CompositeBottom: White-balanced Final Version And some traveling fibers make an appearance. Everyone got this correct based only on the monochrome. Beats me how it looks different in monochrome than the UV shot F. They look alike to me. Link to comment
Andrea B. Posted July 10, 2017 Author Share Posted July 10, 2017 D = Visible = Baader UV/IR-Cut Top Left: Monochrome Top Right: Raw CompositeBottom: White-balanced Final Version Nobody got this one correct. Link to comment
Andrea B. Posted July 10, 2017 Author Share Posted July 10, 2017 E = UV+IR = Schott UG-11 Top Left: Monochrome Top Right: Raw CompositeBottom: White-balanced Final Version One person got this correct. Link to comment
Andrea B. Posted July 10, 2017 Author Share Posted July 10, 2017 F = UV = KolariU Top Left: Monochrome Top Right: Raw CompositeBottom: White-balanced Final Version Same remark: Everyone got this correct based only on the monochrome. Beats me how it looks different in monochrome than the UV+Vis shot C. They look alike to me. Link to comment
Hornblende Posted July 10, 2017 Share Posted July 10, 2017 UV + VIS is slightly lighter. Link to comment
Andrea B. Posted July 11, 2017 Author Share Posted July 11, 2017 I was thinking that I should repeat this kind of thing for landscapes. That would probably be more interesting and relevant.Thanks to my 3 participants! Link to comment
Alaun Posted July 11, 2017 Share Posted July 11, 2017 I had 2 correct (A and D). That raised the question, how big is the probability to get 2 correct by chance? With 6 to place there are 720 combinations. If you fix 2, there are 15x24 combinations left. Which makes a 15x24/720 chance (that is 50%).Is that correct? Link to comment
Andrea B. Posted July 12, 2017 Author Share Posted July 12, 2017 A little bit too high, Werner. If you fix 2, then there are not 15*4! combinations remaining. There are rather 15*3! combinations remaining. We have to omit the combinations which have "matches" in the remaining 4 placements. So 15x6/720 = 1/8 = 12.5%. Combinatorics is maddening stuff!!!! I hated it in school!!!! Link to comment
Alaun Posted July 12, 2017 Share Posted July 12, 2017 Yes, maddening stuff. Hated and liked it in school at the same time! I was to fast yesterday, did the calculation in a hurry. The remaining combinations are (4!/3!+3!/2!+2!/1!) =9 :) and this times 15. so 135/720 so 18.75% Link to comment
Andrea B. Posted July 12, 2017 Author Share Posted July 12, 2017 This is too funny! OK, I will try again. We both agree on the 15 and the 720. :lol: :lol: Link to comment
Andrea B. Posted July 12, 2017 Author Share Posted July 12, 2017 (arghhhhhh!!!!) I left out the 3 arrangements (...or, derangements as they are properly called...) where two of the photos "exchange labels". So should have written: 15*(6+3)/720 = 18.75%. Those 3 derangements I omitted are:6587 (1st & 2nd) or (3rd & 4th)7856 (1st & 3rd) or (2nd & 4th)8765 (1st & 4th) or (2nd & 3rd) Finally !!! Hurray !!!(Now *I* am deranged. Smile.) Link to comment
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