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UltravioletPhotography

UV, IR, VIS and UV/VIS, Tasmania visit 2020


JMC

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We had a trip to the top of Ben Lomond, Tasmania, today. Managed to get some shots with my multispectral EOS 5DSR, and the Asahi Ultra Achromatic Takumar 85mm. UV (Baader U), UV/Vis (BG39 2.5mm, Chinese copy), and IR (Hoya R72). These were all at ISO400, and f16 on the lens. Saved as RAW and jpeg monochrome in the camera. I'll process the RAWs when I get home and put these up too. For now these are just the jpegs, resized in Photoshop and auto-contrasted.

 

UV - 1/2s exposure (ISO400, f16)

post-148-0-44831700-1578820194.jpg

 

UV/VIS - 1/80s (ISO400, f16)

post-148-0-13428100-1578820269.jpg

 

IR - 1/125s (ISO400, f16)

post-148-0-78055300-1578820220.jpg

 

I had originally planned on this being a UV, Vis, IR set, and stupidly used the BG39 2.5mm (Chinese copy) without an additional UV/IR filter, so hence my Visible image is actually UV and Visible and shows more haze than expected. There is also a small movement on the UV/Vis one compared to the other 2. While I was on a tripod, the camera moved slightly for the BG39 shot.

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Jonathan,

Very cool images. Between yours and Bill's, I now need to try some UV scapes of the Potomac River. The rapids would look great in UV with a haze look.

 

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Rayleigh scattering in action. Deeper IR would have yielded a black sky I guess.

Also, is the UV photo underexposed? The rock side looks darker, maybe the haze was brighter?

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Very enjoyable seeing this Tasmanian scene.

 

Looking forward to more from your travels.

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The news about the australian fires reached Italy as well as the rest of the world. Is that the sun? I hope your health doesn't get affected by all that smoke, has it been there for a long time?
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Tasmania is not too bad at the moment, no fire alerts when I last checked. However the main land is still being hammered. Huge impact on people and wildlife. DaveO, that looks like the sky when we landed at Sydney last week. Scary stuff.
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Few more pictures from Tasmania.

 

Firstly an IR one from the Alum Cliffs lookout, near Mole Creek. Taken using a Heliopan 715 filter and converted to monochrome.

post-148-0-23026200-1578981936.jpg

 

Secondly, a day after the Alum Cliffs one above, one from Devils Gullet lookout, Mayberry. Again with the Heliopan 715 filter. Also included is a normal visible light image of a similar view of the same area.

post-148-0-73716400-1578982163.jpg

 

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Very different weather conditions today. There was alot of smoke from the mainland which has blown over to Tasmania. Unlike with normal haze, the IR picture does not cut through the smoke.

 

No more UV pictures at the moment, not had the opportunity to get anything nice.

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Lovely photos. I know LWIR can work through smoke, so it must be the relative size of the particles involved compared to the wavelength. LWIR is ~10 microns, which is probably enough to see through 1 micron smoke particles.
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Jonathan, I really like these comparison photos. Looks like you are having very nice time in a very nice place. I am happy for you. Enjoy! I am enjoying your photos. :grin:
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Lovely photos. I know LWIR can work through smoke, so it must be the relative size of the particles involved compared to the wavelength. LWIR is ~10 microns, which is probably enough to see through 1 micron smoke particles.

Since Rayleigh scattering occurs only (again, smooth transition) when the particles are significantly smaller than the wavelength of the EMR you are using (visible and near-infrared in this case), smoke particles scatter light with "normal" wavelengths in a non-wavelength-dependent way (Tyndall scattering). LWIR, having much longer waves (~8-14 µm) is much "longer" than 1 µm smoke particles, and penetrates them because Rayleigh scattering is inversely proportional to the fourth power of the wavelength, so longer waves are scattered much less. This may not be the reason why LWIR (and thermal cameras) are so good to see trough smoke (they are used by firefighters to see in a smoke-filled environment), but maybe this is part of the reason?
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Firefighters have high temps to help them (photographically anyway). Yeah, I’m pretty sure it’s Raleigh/Mie scattering issues with regard to the smoke.
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Ah, we have internet again. Few more IR pictures with the Heliopan 715 filter. One from cemetery at Rosebery, and two from the window of where we stayed at Tullah for a night.

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Nothing so glamorous, I think it's just a post of a hose pipe. Got some more UV shots today. Will share when I've had chance to edit them.
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Another set of three images, this time from Trial Harbour on the west coast of Tasmania. UV (Baader U), Vis (BG39 2.5mm + B+W486 UV/IR blocker), and IR (Hoya R72), with the Multispectral EOS 5DSR and UAT 85mm lens. ISO400 and f16 on the lens. Images saved as RAW and JPEG monochrome. These are the mono jpegs.

 

I remembered the UV/IR cut filter ths time, so Vis really is Vis and not UV/Vis.

 

UV - 1/4s

post-148-0-79252500-1579328481.jpg

 

Visible - 1/125s

post-148-0-54294700-1579328492.jpg

 

IR - 1/250s

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Taken at about 1PM on 17th Jan 2020.

 

Interesting to see the seaweed on the beach looks light in the IR and dark in the Vis and UV like the foliage. I guess the seaweed also has chlorophyll in it?

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The contrast is interesting. Your UV beach is dark and mysterious. Like you went there to hide a body.

Then in IR, its a light happy place to take the kids to.

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Bill De Jager
Some really nice shots, Jonathan. When I was in school a student from Tasmania showed me a lot of her photos from hiking around different parts of the island. Spectacular place!
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Ah, internet again for a few hours. Thanks for the comments all.

 

Three more images. This time the view from Horsetail Falls, Queenstown, Tasmania, looking roughly westwards. Three images - UV (Baader U), UV/Vis (BG39 2.5mm Chinese copy, no UV/IR blocking filter, hence UV/Vis), IR (Hoya R72). Taken with the EOS 5DSR multispectral conversion from MaxMax, and a UAT 85mm lens. ISO400 and f16. Images saved as RAW and monochrome jpeg in the camera. These are the jpegs, resized for here.

 

Unfortunately this time I didn't have the tripod with me, so I had to, well, guess orientation, hence they don't line up perfectly.

 

UV - 1/4s (I upped the ISO to 800 to reduce shake)

post-148-0-98308600-1579510277.jpg

 

UV/Vis - 1/125s

post-148-0-17546500-1579510290.jpg

 

IR - 1/200s

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Couple of things to note. Towards the right hand edge of the image is the local airstrip, which looks different in the 3 shots. In roughly the middle of the image in the foreground, you can see 'QUEENSTOWN' in white letters in the UV/Vis and IR image, but not the UV one. In fact the full message is 'WELCOME TO QUEENSTOWN', with the 'WELCOME TO' just above the 'QUEENSTOWN', however we went on a tour with one of the guys who had repainted the sign a couple of years back, and he said that they had run out of paint (they took 10l up there and barely had enough to do QUEENSTOWN). Hence it now looks like it just sayd 'QUEENSTOWN' although you can see the other bit of the message in high res images. The writing doesn't show up at all in the UV image. I presume the white paint has a high loading of TiO2 which is absorbing the UV and making it look dark. Also I can see clouds in this UV image, unlike the others. These clouds were quite close, so I'm guessing haze wasn't sufficient to block them like in the other ones.

 

We're going on a 4 day flight/cruise down in the south west of Tasmania tomorrow. This part of the island has no access other than flying in (unless you want to walk for 7 days), and is uninhabited. I hope to get some more images from down there. On our flight down there we are limited to a total of 12kg of luggage each, to last for the 4 days. 11kg of mine is camera gear, tripod and laptop. I guess I'll be trying to wear as much of my extra clothing requirement as possible.

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