News
Recent sites, studies, and publications mentioning UVROptics
Natural Science Imaging and Photography (Applications in Scientific Photography) 1st Edition edited by Michael R. Peres (Focal Press, 2021) “Red floral nectar that absorbs ultraviolet light is produced by a new Peruvian species, Jaltomata weigendiana (Solanaceae)” By Thomas Mione, et al (Phytologia (Mar 16, 2018)) “Breeding system features and a novel method for locating floral nectar secretion in a South American nightshade (Jaltomata quipuscoae)” By Thomas Mione, et al (Plant Biosystems, 2019) “Sex-specific floral attraction traits in a sequentially hermaphroditic species” By Kristen Peach, et al (Ecology and Evolution, 2020) “Climate Predicts UV Floral Pattern Size, Anthocyanin Concentration, and Pollen Performance in Clarkia unguiculata” By Kristen Peach, et al (Frontiers in Plant Science, 2021) “The Ecology and Evolution of Floral Form and Function in Clarkia unguiculata” K Peach – 2020 “Role of coloration in antipredator strategies of Pristidactylus achalensis (Squamata: Leiosauridae) related to sex and stages of predation” MarĂa Del Milagro Torres, et al (Biological Journal of the Linnean Society, 2021)
Testing of UVROptics' SEU Gen2 Filter by Ultravioletphotography.com -- 7/2018
An exhaustive series of real-world tests were conducted by Andrea Blum, of Ultravioletphotography.com, of the UVROptics' SEU Gen2 UV Bandpass filter. Andrea's summary, with links to the 11 parts of the testing, may be found here -- SEU Gen2 Filter Test Summary
The conclusions of the testing included the following passage [emphasis ours]:
- Exposures times under the SEU Gen2 are faster than with other well-known UV-pass filters, all other factors being equal, because the filter's highest transmission rate, between 60-73%, is in the 370-400 nm range where sunlight provides the most UVA. This aids outdoor UV captures under hazy or overcast conditions when there is less UV reaching ground level.
- The SEU Gen2's 70-73% transmission between 380-400 nm is very useful for non-specialist, UV-capable lenses many of which do not reach past 370 nm or so.
- The SEU Gen2 nicely preserves the sharpness and detail offered by the lens in use. It is impressive on a lens like the UV-Nikkor 105/4.5 (rig on tripod, remote shutter triggering). I was not able to fully explore monochrome comparisons, but I really liked the Black & White conversions from the SEU Gen2.
- There is no Visible or IR leakage in photos made under a UV-cutting longpass filter stacked over the SEU Gen2 and given the same exposure as the UV-only frame. There is a very good transmitance chart on the product page showing the out-of-band blocking.
- The SEU Gen2 is well made. Protective screw-on caps are included in the purchase and should be used for storage to protect the mirrored surfaces.
- The D610-mod white-balanced false colour in a finished SEU Gen2 landscape photo is a very pleasant mix of false-blue and false-green. False-yellow may also show up in some photos. As with any other UV-pass filter, the SEU Gen2 false colours are dependent on subject distance, white balance algorithms and converter used in addition to the camera and lens used.
- The SEU Gen2's small passage of violet light (.2% between 400-406 nm) does not affect the UV capture. We already know this from using other UV-pass filters having a minor passage of violet light. Light around both sides of 400nm, say approximately 390-410 nm, is recorded similarly by our cameras.
- The higher transmission peak of the SEU Gen2 at 392nm and high transmission between 380-400 nm may - for some subjects - offer a slightly different UV view than what is captured by a filter such as the BaaderU with a peak at 350 nm. This will be fun to explore further for amateur botanist me.
All UVROptic's filters are manufactured in New Hampshire, USA, of the finest optical glass.