I have been playing with UV photography on a Full spectrum Canon EOS 600D (Canon EOS REBEL T3i) for some time. I wanted to see the UV markings on flowers that some animals / insects etc can see.
I discovered a world where paint patch ups, metal alloys and many other things also look unique and different when viewed in UV.
Early on I tried a sunscreen experiment where I painted half of a subjects face and then filmed the person, hoping to see the blocked UV. I was unimpressed. It caused a greyish hue or cast over the face, but nothing with any real impact.
Then, a little later, Thomas leveritt posted a Sunscreen video on Youtube. I have been trying to replicate it ever since.
I figured that Thomas leveritt may have had more than a full spectrum conversion done to his camera. Maybe they also removed the Micro filters ? Perhaps he is using a quartz lens ?
Finally, I have similar results. Thanks to Antoni Łoskot for pushing me hard to find a solution. It turns out that with a Canon 50 mm 1.8 EF canon lens, I can get the same results.
My understanding with UV has been turned on it’s head or maybe, Canon cheap lenses are *real* cheap.
I have been acquiring old lenses. lenses that are manual focus, with as few glass elements as able, before UV blocking multi coatings came into fashion. Lenses that need EF adaptors and limited to a specific focal range. I have then been adjusting the lens to move focus into the UV spectrum, from the Visual spectrum. Tedious and painful.
All of this so I can reduce ISO to 400 and time to 1/25 sec. But .. am I looking at this wrong ?
Maybe with the sunscreen video, you can have a higher ISO and slow shutter time as the subject is moving and you do not notice ? Maybe I am looking for a UV response in the spectrum too low ? Does sunscreen react at a higher wave length ?
so, using a Canon EF 50mm 1.8 lens with a 52 mm to 1.25 ” adaptor and Baader U filter, I get the results I need.
1/13 sec and ISO 800 looks a little blurry for a still shot but the Sunscreen is a black colour, not grey. This is what I want. Finally, the results I wanted !!!
I will have to test further but maybe my EL Nikkor lenses will work better for flowers ?
I have to use my EL nikkor with a bellows to get focus. With the canon EOS and EF lens config, I get Auto focus in the UV range !!! Awesome. Less fiddly.
I have tried a Canon L 24-70 mm and I needed ISO 3200 at 3-4 seconds to get any UV response. Maybe the difference of L professional series to “kit” cheap lens ?
Regardless, I am happy it works.
My Full spectrum mod was done by eeassa (Ehab) on eBay. I love it !!!
#1 by Antoni Łoskot on May 6, 2015 - 4:41 pm
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Right on! I am glad it finally worked out. Its motivating for me as I am to make similar commercial project here in Poalnd 🙂 Keep my fingers crossed 😉
#2 by mickyj on May 27, 2015 - 10:36 pm
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If you need any questions answered, let me know 🙂
#3 by Helene on May 7, 2015 - 10:34 pm
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i assume it is working better with fixed focal lenghts, less glass and a shorter “path”, although this is far less important at those distances… i will try other fixed focal lengths and report back here.
#4 by mickyj on May 27, 2015 - 10:36 pm
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Your assumptions are 100% correct. Good luck !
#5 by William on May 25, 2016 - 3:20 pm
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Hi Micky,
I came across this page and tried to replicate it on my own.
I got a Canon 600D, which I took to a shop to have the IR cut filter removed as shown here – http://dslrmodifications.com/rebelmod450d1.html – keeping the Low-pass filter 1. Then I bought a Venus-U filter from Optolong – http://optolong.com/en/products/astronomy-filters/broadband-filter/343-broadband-filter-venus-u – as the Baader U was not easily available.
I used a EF 50mm 1.8 and fixed the 2″ Venus U filter in front using a blank 52mm ring that I took from an old UV filter (ring only, UV glass removed).
I took a few shots of faces with partially covered sunscreen lotion but did not see any dark areas. I am honestly not even sure if my sensor is receiving UV only or if UV is still being blocked somewhere.
Would you know what I am missing? I would assume that if anything is still blocking the UV, I would not see anything on my shot as even visible light is blocked – at least as the tech specs of the Venus-U says.
I would appreciate any help.
Regards,
William
#6 by mickyj on December 16, 2016 - 1:31 pm
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I have emailed you