brucek Posted November 9, 2006 Share #1 Posted November 9, 2006 Advertisement (gone after registration) Here's hoping I can get the photos uploaded. I haven't tried this on the new Forum yet... Attached are some samples of normal, IR and UV photos taken with the M8. (Please forgive the lack of artistic photos - I need to get some work done!) The first series is of the field behind my house. First photo is without a filter; second is with a Hoya R72 filter; the third is a UV filter from LDP with a 270-375nm bandpass. The unfiltered photo has not been massaged; the IR photo was desaturated and I then applied auto contrast; the UV photo was severely underexposed (I didn't check the histogram) so was adjusted accordingly. I see very little difference between the IR and UV photos, which agrees with what I've seen with my modified Sony F828. I was also surprised to see that the M8 meters the IR photos very well. I used no EV compensation on any of the pictures. So, hopefully, here are the photos: Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/8842-m8-ir-and-uv-photos/?do=findComment&comment=88543'>More sharing options...
Advertisement Posted November 9, 2006 Posted November 9, 2006 Hi brucek, Take a look here M8 IR and UV photos. I'm sure you'll find what you were looking for!
j. borger Posted November 9, 2006 Share #2 Posted November 9, 2006 Thanks for sharing .... how were exposure times... Link to post Share on other sites More sharing options...
brucek Posted November 9, 2006 Author Share #3 Posted November 9, 2006 Here are the second series of tests. This time the UV exposure was right-on. The order should be: No filter, IR and then UV. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/8842-m8-ir-and-uv-photos/?do=findComment&comment=88552'>More sharing options...
johnastovall Posted November 9, 2006 Share #4 Posted November 9, 2006 The thing that jumps out at me is the vertical band 2/3 of the way to the left in the UV shot of the field. That is most disturbing. Link to post Share on other sites More sharing options...
brucek Posted November 9, 2006 Author Share #5 Posted November 9, 2006 Thanks for sharing .... how were exposure times... J.: I knew I forgot to include something... <sigh> All pictures were done with a second series Tri-Elmar at f/8. The first series were done at 28mm; the second at 50mm. Camera was set to an ISO of 320. Exposrue times were as follows: None1 1/1500 IR1 1/11 UV1 1/11 None2 1/1000 IR2 1/30 UV2 0.3s Bruce Link to post Share on other sites More sharing options...
brucek Posted November 9, 2006 Author Share #6 Posted November 9, 2006 The thing that jumps out at me is the vertical band 2/3 of the way to the left in the UV shot. Again, that picture is severely underexposed so I don't know how much that would affect it. And, unfortunately, I really can't spare the time to run the test again right now. Link to post Share on other sites More sharing options...
chetccox Posted November 9, 2006 Share #7 Posted November 9, 2006 Advertisement (gone after registration) The thing that jumps out at me is the vertical band 2/3 of the way to the left in the UV shot. That is most disturbing. Yes, that was the first thing I noticed as well - plus the dust on the sensor already as seen in the blue sky. Link to post Share on other sites More sharing options...
Vivek Iyer Posted November 9, 2006 Share #8 Posted November 9, 2006 The first series is of the field behind my house. First photo is without a filter; second is with a Hoya R72 filter; the third is a UV filter from LDP with a 270-375nm bandpass. The unfiltered photo has not been massaged; the IR photo was desaturated and I then applied auto contrast; the UV photo was severely underexposed (I didn't check the histogram) so was adjusted accordingly. I see very little difference between the IR and UV photos, which agrees with what I've seen with my modified Sony F828. Bruce thanks for showing. The reason that there is no difference between the 'UV' and the IR captures is because both are IR captures. The bandpass filter you employ for 'UV' will also transmit in the IR (but no Visible). Since no special lens that is tranparent to UV is employed here (or in your Sony), only IR gets recorded. Link to post Share on other sites More sharing options...
brucek Posted November 9, 2006 Author Share #9 Posted November 9, 2006 The reason that there is no difference between the 'UV' and the IR captures is because both are IR captures. The bandpass filter you employ for 'UV' will also transmit in the IR (but no Visible). Since no special lens that is tranparent to UV is employed here (or in your Sony), only IR gets recorded. Vivek: That isn't the way I read the specs for the filter (Quantity XNite30030) The way I read that is that the filter has a cutoff before the IR fequencies. But then I'm by no means an expert in this! Bruce Link to post Share on other sites More sharing options...
Vivek Iyer Posted November 9, 2006 Share #10 Posted November 9, 2006 Bruce, Unfortunately, the little hump that shows in the spectrum shown for this filter (Hoya U-340, X-nite calls it by another name) from 700-800nm is the one that is transmitting IR when no UV can get through your lens (here or on the Sony cam). If you have, try an old Elmar 50/3.5 (uncoated), this filter plus an IR cut filter. The bset filter for "true" UV captures would be the Baader U filter (google). This transmits from 300-400nm and absolutely nothing else. It looks like this: http://www.filmlives.net/files/baaderu1_117.jpg (the one on the left that looks like a mirror). Link to post Share on other sites More sharing options...
johnastovall Posted November 9, 2006 Share #11 Posted November 9, 2006 Again, that picture is severely underexposed so I don't know how much that would affect it. And, unfortunately, I really can't spare the time to run the test again right now. Why I was struck by it is that it's almost in the same place as banding in this example posed on FM in this thread. If you load it to the desktop and zoom it it up a bit. Link to post Share on other sites More sharing options...
brucek Posted November 9, 2006 Author Share #12 Posted November 9, 2006 The bset filter for "true" UV captures would be the Baader U filter (google). This transmits from 300-400nm and absolutely nothing else. Vivek: Thanks for the info! Bruce Link to post Share on other sites More sharing options...
Vivek Iyer Posted November 9, 2006 Share #13 Posted November 9, 2006 You are welcome, Bruce. Come and visit us on the "Beyond the Visible" forum- dedicated to UV and IR. Link to post Share on other sites More sharing options...
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