Anne Hall Posted August 14, 2014 Share Posted August 14, 2014 This is my first test. I understand now that I should be using black and white film?Does anyone want to rent me their Baader or Schott UG11X? I am doing a single project w UV and would need filter for approx 2 weeks. Seems a little much to buy filter just for this use. Thoughts? This is my first test. Not sure what I have here. Anyone else have interpretations of what is/isn't working? Link to comment
Andrea B. Posted August 14, 2014 Share Posted August 14, 2014 Bjørn can answer film questions. I'll ping him.He's been out in the field so it might take a day for him to get back to this thread.I know absolutely zilch about film! Anybody else out there knowing about film for UV photography, please add your help, thanks! I had thought that the B+W 403 could be used with film without an IR blocker.So let's also determine that.If not, then I can help you with a short-term UV-pass filter loan. I'm not sure what you have there in the photo. There is no detail or depth. That may be because you are using the wrong film or because you didn't have a UV light source strong enough? So that needs to be figured out.Was the photograph made outdoors? If so, was there strong sunlight?How long was the exposure for? At what aperture?(Is this a sunflower in the photo?) What subject do you plan to shoot in your UV series?Is the shoot indoors or outdoors?Answers can help us provide some advice. :D Link to comment
JCDowdy Posted August 14, 2014 Share Posted August 14, 2014 Here is a link to an old Kodak publication Ultraviolet & Fluorescense Photography from the days of film that might make a good starting point. This is the first thing I ever read about the subject, and it was 15 years past the second printing then! Link to comment
nfoto Posted August 14, 2014 Share Posted August 14, 2014 Cannot make head or tails of this photograph. Presumably it is a Rudbeckia or Helianthus of some kind? If so, this could explain the relative brightness of the outer parts of the rays ("petals"). We would expect to see a very dark centre in the flower head, and as this is a film-based capture, probably not black like we observe on digital UV. However, here it is rendered nearly without detail in pale orange-yellow. The white background presumably is done in post-processing of the film scan. I would like to know the details of the setup before commenting further. The 403 filter should be adequate for b/w films as they rarely extend sensitivity into the near IR (unless an IR emulsion is used). However, for colour work you might think about adding an IR-blocking filter to the 403. This because these films might have extended red sensitivity enough to be influenced by the IR leak of the 403 filter. The IR leak may overpower the UV pattern and potentially washing it out. There is the tell-tale mark of a light leak in the photo as well (brighter streak in the middle). So look carefully for any leaks. Link to comment
Anne Hall Posted August 21, 2014 Author Share Posted August 21, 2014 Hi All Thank you for your initial thoughts. Here is an image shot normally on color film. It was outside in bright sunlight. Maybe I should be shooting on black and white film? My setup is a 4x5 camera, kodak daylight film, el-nikkor enlarger lens, B+W 403 filter. The uv exposure is long, 15 seconds or so bc I have to manually cover up the enlarger lens to stop exposure at f45. Does this help? I really appreciate all suggestions and offers! Anne Link to comment
Anne Hall Posted August 21, 2014 Author Share Posted August 21, 2014 Thank you JCDowdy for the old kodak UV pamphlet. Amazing. From it I gather that mercury vapor lamps are a good source of UV for small subjects. I may try this. The not having a shutter to do fast exposures is a bit of an issue that I didn't consider when buying an enlarger lens... Link to comment
JCDowdy Posted August 21, 2014 Share Posted August 21, 2014 Those types of lamps are difficult to source and rather hazardous and likely unnecessary as you should have sufficient sunlight UV. That B+W 403 filter has a secondary transmittance band as Bjørn mentioned which you may need to suppress. Review the The UV/IR Filters Sticky for what filters to use, especially if you may already have one on hand. Link to comment
Andrea B. Posted August 22, 2014 Share Posted August 22, 2014 The orange sunflower in UV should show a very dark center and bright petal tips. I'm not sure how the leaves should look because that can vary amongst different flower species, but they will probably be moderately dark. Sunflower in UV after white-balance correction:http://www.ultraviol...hoot-out-in-uv/Another sunflower:http://www.ultraviol...leaf-sunflower/ The yellow or blue colours in the UV sunflower photos are false, an artifact of the bayer colour filter in our digital cameras. The false colour is brought out by performing a white-balance step in the editor. I think that repeating the experiment using black & white film is a good next step. As Bjørn pointed out, the 403 should work with B&W film. The 403 is known to pass some Infrared (longwave) light. This can give a washed out appearance to a UV photo. That might be what happened in your first UV photo above using the colour film due to its different response, as Bjørn mentioned. We usually block IR with a blue-green filter, which perhaps you already might have? Schott glass BG39 in a 1mm thickness is a good choice to stack over the 403. This will increase the exposure time. Link to comment
nfoto Posted August 22, 2014 Share Posted August 22, 2014 I am puzzled by this photo, as it definitively NOT looks "UV", film or not. In fact, it looks like a pale version of a 'normal' picture. In the film days, film makers implied excessive UV would cause a blueish cast, so people bought "UV-filters" (should have been designated anti-UV filters of course, but they weren't) to get better colours. The further implication is that in case film received just UV and nothing else, the image would turn completely blue. In fact, the recommendation of that time was not to use colour film, because the output would just blue and noting else. So b/w was recommended. We all know that raw digital UV captures tend to look red or orange, rarely blue. This results because the main UV response of the system is in the R channel (due to the nature of the RGB dyes of the Bayer matrix) when all spectral components outside the UV are prevented from reaching the digital sensor. If we carefully white balance such captures against a spectrally neutral (flat response over the UV band, i.e. "UV white"), the now familiar UV false-colour palette is formed. However, if there is a leak of the spectral bands outside UV, and in particular in IR, the digital UV palette becomes washed out and in some cases, even starts to look a poor rendition of the usual visible colours we see with our eyes. Thus, what I believe has happened here is that the colour film has a built-in UV blocking layer and the red sensitivity goes towards the borderline region of deep red and near-IR. By design, a lot of daylight colour films behaved like that in the old days. Couple this with a lens that transmits OK but not very well in UV, and a UV filter that allows not all UV to pass plus leaks a lot in IR and in the violet area of the spectrum, and you actually have a synthetic natural-colour capture. Synthetic because the designated colour bands haven't been employed as they should be, but the final effect is similar nevertheless. So, what to do? First, do not use daylight-balanced colour film material. It will have low UV response and exacerbate the problems you are encountering. Use either tungsten-balanced colour or b/w film. Second, if using colour film you need better protection against IR (or, actually, you wish to attenuate deep red and borderline near-IR) and that means adding a IR-cutting filter such as BG-38, BG-39, BG-40, or S8612 to the 403 filter. Third, for best UV performance, go digital (this may clash with other considerations you might have with your project, but should be mentioned nevertheless). Link to comment
Anne Hall Posted August 22, 2014 Author Share Posted August 22, 2014 Thank you for all of these suggestions. It is a little bit difficult to select the next course. The old Kodak pamphlet contradicts some of the suggestions here. It says not to use tungsten film, etc. Do you know if there are any members in the New York / New England area? I think partnering with someone who has the equipment and technical expertise might be the best way to go about this project. Otherwise it sounds like adding an IR filter would help. thank you Link to comment
nfoto Posted August 22, 2014 Share Posted August 22, 2014 The Kodak info is plainly wrong. I used Fuji RTP film during the '90s for all my film-based UV shooting with great success. Andrea is the one to ask. Link to comment
JCDowdy Posted August 22, 2014 Share Posted August 22, 2014 The recommendation against tungsten film is in Section II-Fluorescence Photography, expressing their preference for the color balance of daylight film for imaging UV-induced fluorescence. What we are talking about is reflected UV photography, as described in Section I - Ultraviolet Photography of the Kodak publication. Perhaps you are confusing the two, or perhaps we are confusing which you are intending. Link to comment
Anne Hall Posted October 26, 2014 Author Share Posted October 26, 2014 Thank you all for your suggestions. I am finally able to come back to this project and devote some more time to explorations. You are right, I was reading the Kodak pdf straight through and didn't realize I had left the UV section and was reading the fluorescent section. So, my next test will be : Film : Tungsten or black and whiteUV filter : Hoya 403Infrared cutting filter (for color film only?) : Schott glass BG39 in a 1mm thickness or BG-38, BG-40, or S8612Lens : El-Nikkor Does anyone think there is an issue with the fact that I can't make a precise exposure with the enlarging lens because it doesn't have a shutter that opens and closes? I have dealt with this by using a long exposure but it's not ideal. Thank you for your help. Link to comment
nfoto Posted October 26, 2014 Share Posted October 26, 2014 The S8612 has proven itself to be a very attractive IR-cut filter when you don't want to use dichroic filters. It apparently performs better than more familiar BG-series. You probably will have quite long exposures for UV, so using a lens without a shutter shouldn't be a big issue (assuming static subjects of course). I've done lots of shutterless exposures for UV as well as for high-magnification photomacrography and seen little issues therein. Be aware, however, of preventing the sun itself from being recorded within the frame as you may severely overexpose the film locally to create a solarised image. Link to comment
JCDowdy Posted October 26, 2014 Share Posted October 26, 2014 Knowing essentially nothing about 4x5 cameras I must ask a naive question, what kind of lens/shutter assembly did it have originally? The reason I ask is that the native lens may be UV-capable, especially if it is a vintage lens. Link to comment
Anne Hall Posted November 14, 2014 Author Share Posted November 14, 2014 Thank you Bjorn and JC Dowdy My lens is a Rodenstock that I bought new about 10 years ago, so I think it is coated. I am using the setup described earlier. What do you see in these pictures? Film : Ilford HP5 Black and White ISO 400UV filter : Hoya 403Infrared cutting filter : BG-40Lens : El-NikkorBright sunlight Link to comment
colinbm Posted November 14, 2014 Share Posted November 14, 2014 Nice collection Anne.Col Link to comment
rfcurry Posted November 14, 2014 Share Posted November 14, 2014 You are an artist with the camera, Anne! Link to comment
Andrea B. Posted November 14, 2014 Share Posted November 14, 2014 The Peruvian Lily (not really a lily) looks correct in UV. It usually has a moderately dark to dark lip in UV, and you got that.The tulip or crocus in the last shot looks correct in UV. They go very dark in UV but with some shiny iridescence. And you got that.Hard to say about the big lily or the chrysanthemum because they can vary in their UV appearance depending on species/variety.But the big lily and chrys look good too.I think you are definitely on track. I want Bjørn to look at the new examples too, so I pinged him. Remember that your first flower above - the Sunflower - is a very good test flower which should be fairly easily available in NYC. Sunflowers have a dark ring in UV around their dark center disks making for a UV-dark "bull's eye". The outer tips of the rays would be UV-bright in contrast. The size of the sunflower bull's eye varies by sunflower variety, but there are always some bright tips. If you can nail a sunflower's UV-dark bullseye, you are for sure good to go. It might be useful to shoot a sunflower in UV prior to each session with your other subjects just to have a known reference? Link to comment
nfoto Posted November 14, 2014 Share Posted November 14, 2014 These look pretty much as one would expect from a genuine UV capture of the given species , rendered in b/w. I suggest you follow Andrea's tip and test out a few sunflowers. Is there a trace of flare on some of these pictures (Peruvian Lily for example)? Link to comment
Anne Hall Posted November 15, 2014 Author Share Posted November 15, 2014 Thank you all. So glad to hear the technique is progressing. I was about to give up hope!I will try a sunflower.I didn't adjust the scan at all so there may be some flare from the plastic wrap around the tissues I used to prop up the "lily."I will make a proper set up next time now that it seems I am more on track. yay! Anne Link to comment
OlDoinyo Posted November 24, 2014 Share Posted November 24, 2014 The IR-cut filter is probably redundant here, as the response of most film peters out around 680 nm. You can get visible leakage in longer exposures, but an IR-cut filter will not help that. Link to comment
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