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UltravioletPhotography

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I went to a local zoo yesterday and took some comparison shots in IR and UV.

 

UV-shots with a Canon EOS 6D, converted to monochrome ([Edit:]Bayer-array removed[Edit]) "almost"-UV (by LDP LLC, so have to use one additional filter [Edit:] internal filter is X-Nite 330, external filter X-Nite BP1[Edit]), lens Russian MC 3M-5CA 500mm f/8 mirror lens. ISO 3200-6400, shutter-speed 1/125 for the camel, 1/30 s for the rest. I forgot to bring my monopod and need to practice more with that lens, so the sharpness is not anything to brag about, on top of which I really do need to clean my sensor, but here they go.

 

In that order: Aloof camel, hungry mini-pony, sleeping lion, watchful serval, active llama, itchy Angus-bull.

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Stephan, Very nice photos!

I think MaxMax usually puts BG38 (CC1) in their monochrome conversations, correct? Your camera has the Bayer layer removed?

Is that all correct?

What extra filter are you using on the lens?

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Thanks for the comments. I was interrupted before I could post the IR ones, will do so tonight, and then also answer the questions
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IR-photos: Canon EOS 6D, converted to 700 nm by Sven Lamprecht, lens: Canon 70-200 + 2xTC, f/5.6 and f/6.3, ISO between 100 and 800, shutter-speed 1/400 s; therefore most of them reasonably sharp

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I notice your mirror lens gives photos a ring bokeh, like reflecting telescopes.

 

Yes, that's also one of these love-it-or-hate-it things :smile:

 

I've not yet tried removing the optics at the end, to go for a better UV-transmission, might do that sometimes.

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Stephan, Very nice photos!

I think MaxMax usually puts BG38 (CC1) in their monochrome conversations, correct? Your camera has the Bayer layer removed?

Is that all correct?

What extra filter are you using on the lens?

 

I edited my initial post to answer your questions. What I really like about this is the fact, that there's visible light reaching the viewfinder, so I can shoot as with any other camera - apart from having to go to higher ISOs and slower times. Like I wrote in the other post, I might go for removing some of the optics in the mirror lens.

 

What do the other members here use for UV-telephotos?

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Stephan, I like your camels. :-) What Zoo is that?

Bob has a monochrome converted by MaxMax, it has BG83 installed internally, which was recommended by MaxMax to remove or mostly attenuate the IR because IR doesn't do well with the monochrome conversions,

at least the Nikon varieties, and don't ask me why, I have no experience with monochrome conversions myself.

With the monochrome/BG38 internal conversion one can use them for anything in the UV to Visual range, and even some (attenuated) of the IR range 700nm to 800nm.

Although the MaxMax "X-Nite 330" filter name might imply a UV+Blue+Green+IR mix (U-330 or UG5), looking at their graph shows something more like U-340 (UG11).

So stacking with their BP1 would limit the transmission to UV bandpass, depending on actual leakage with the BP1.

 

I guess my question is, why did you choose to have the X-Nite 330 installed? I guess because that removes the U filter from the optical viewfinder view,

thus you can use the optical viewfinder for focus.

 

I think when it comes to UV at least you can focus better with the live view. Also the metering system should be using the live view, not the meter being used when using the optical viewfinder.

I think those are different, at least with Nikon, perhaps your Canon is set up differently.

If you didn't have the filter installed inside, you could use the camera for a more versatile range just by putting the filters on the front.

 

The other question is your high ISO. With a monochrome conversion I would think the sensitivity is much better, and UV photos could be done even hand held with much lower ISO.

The only conclusion I can imagine here is your lens...

So to answer your question, "What do the other members here use for UV-telephotos?", my answer would be, certainly not a mirror lens.

I don't have the same mirror lens you are using, but I have 4 others, all of which work good for UV with the mirror section of the lens, but when it comes to the read section where they have a few small lenses.

Sometimes those lenses can be the culprit, but often times there is a real clear filter which you can screw off. The coating on that rear filter, and/or the rear lenses will drop UV transmission to a quite poor level.

I you may want to try other lenses to see if they lower your ISO.

There are a lot of older 400mm and shorter lenses that transmit UV quite acceptably. For example, Lentar 400mm should work quite well, and would be easier to focus I am betting.

 

Again, I am way over my head here given that I don't own any monochrome converted cameras, just trying to figure it out for my self a little though.

And I really like your photos, especially the UV shots, and especially the camels.

Thanks.

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Great comparison between the IR an UV. Especially the cat on the roof. The IR really pops. The camel seems soft in IR but then the markings are very prominent in UV.

 

As for telephoto, I have the Lentar 450 and 400mm lenses. Purchased way before Cadmium foind they work in UV. I still haven't tested mine. My 500mm Tamron Adaptall mirror lens isn't great for UV.

I have a single element fused silica 500mm lens that I plan to use, but still haven't constructed the tube for it. So I am still behind on my telephoto projects.

 

I still have the crazy idea to photograph birds in UV in my yard. But still moving slow.

 

I also was planning on building a hypercentric lens for UV. But that project has also been stalled. I have the 30cm PMMA lens though.

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Steve, with regards to your ISO comment, the monochrome conversion gave about a 2-3 stop improvement on my Canon 5DSR vs retaining the Bayer filter. It also pushes the average sensitivity towards shorter wavelengths a little bit, although in sunlight the actual result of that would be small. Keep in mind that that lens in an unknown for UV transmission (at least as far as I am aware) and is f8 only. As such those ISO's and shutter speeds don't surprise me.

 

I've toyed with having one of my monochrome cameras converted to UV only for my sunscreen imaging, but so far the lack of flexibility you mentioned has put me off. For a clinical environment where it just needs to do one thing it would be ideal though, and it would be good to be able to use the optical viewfinder.

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Again, thanks for the comments, I'll try to address all the points in this post.

 

The zoo is a very small business in Walding, a small hamlet, family style; the animals I've taken photos of are about a fifth of the species present there. As I went with some friends, I couldn't bring some equipment and only had limited time for the photos.

 

I chose this kind of conversion exactly for the reason of being able to use the viewfinder; I can always switch to LiveView, if necessary. However, with longer lenses, I'll need a bright day to bring the ISO down and/or speed up, and on a bright day, LiveView is sometimes difficult. Still, depending on the focus-shift of the lens, this might be the only viable option. On the other hand, for UV-landscapes with a lens around 20 mm, focus-shift should not matter that much, and I can do away with the tripod and shoot handheld without problems.

 

With regards to the mirror lens, I bought it many years ago as a compact means to 500 mm, and a quick UV-test at home proved it to be superior modern lenses like the Canon 70-200 (no surprise here), although the Canon 135 f/2 does not do too bad a job apart from the focus-shift; so I took it along. I didn't want to order one of the tele-lenses recommended, like the Lentar, Noflexar, etc., and later realize that I had a good lens sitting at home :smile: Unfortunately this is not really the case, and to be honest I'm way too clumsy to attempt removing the rear elements and replacing them with some adapter - and even then the protective front lens might be the actual culprit.

 

I checked the other threads with respect to tele-lenses, but have to admit that I've gotten a bit confused as to which of the lenses is actually the best UV-wise; that some of the older lenses were sold under half a dozen brands, doesn't help any. The sticky list also doesn't give a lot of data in this respect, apart from the graph with the comparison of Noflexars.

 

Is there a consensus here on UVPhotography which of the long lenses is THE best one?

 

I've checked on the bay for the Lentar 400, and there are a few offers between 9 and 100 $; The Noflexar is a bit more expensive, and there are also Beroflex, Travenar, Piesker, etc. available, but I'd rather buy just one, so any help is appreciated :smile:

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