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UltravioletPhotography

Infrared block, broad UV and visible pass filter?


Avalon

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Have I ever seen a UVB-only photo? I really don't know if I have.

I totally appreciate anyone who is trying to isolate a UVB photo, on the other hand I want to be realistic here as not to confuse or over complicate the expectations of the larger crowd.

 

Cadmium, take a look at the 300bp10 thread. My last post I have a UVb image with a 313bp25 filter using just the sun.

UVb is possible, but needs some understanding. The sun is a bad UVb source. A good filter stack is needed. For me this has been the 313bp25 filter with the 330WB80 improved. You don't need the $1000 308nm filter. A good uv capable lens is needed. But really you don't need to go all out for super expensive. An alternative is the UKA optics lenses. You will be using a fairly tight band anyways.

 

Cheapest way to UVb I see is a UKA optics 25mm f2.8 c-mount lens at just under $600. A full spectrum converted Olympus camera, this cost will vary, you can even do it your self:

 

http://myphotojourney.co.uk/uv-imaging/uv-capable-cameras/

 

And then the 313bp25 filter $90 stacked with a 330WB80 improved filter $60.

 

So cost can be just around $1000.

 

What do I see in UVb, mostly a couple extra black dots on some flowers. A band on one type a fungus that grew on a tree branch. I haven't looked at a lot of insects yet though. So that may or may not be worth it to you.

 

UVc sound fun, but I know most things absorb, down there so it will be a dark world. The practical uses that I have found for UVc are all looking for or at light. Electrical discharge or explosive flare. Not really at refected light. So I agree with your statement in regards to UVc. Its fun to try, but really not much point.

 

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Disservice? We were not talking about UV pass filters, we were talking about BG filters.

But since you brought it up...

First of all the Baader U is the standard, and when used normally it doesn't leak IR unless you make it, like blocking the UV...

The SEU has a distinct visual-violet (above 400nm) range leak, and because of the unusually higher weighted UV-violet (380nm-400nm) range added to the 400nm+ leak, it produces an odd color balance,

with very bright 400nm+ transmission.

Example:

Jonathan's test (top row L to R, 303nm, 321nm, 341nm, middle row L to R, 355nm, 364nm, 382nm, bottom row L to R, 396nm, 404nm, 405nm):

http://www.ultraviol...dpost__p__22919

 

Jonathan's filters used:

http://www.ultraviol...dpost__p__22555

 

The 365nm centered filters actually tend to 'level out' or balance the camera's decreasing sensitivity in the UV range.

 

Notes:

https://opticalfilte...50nm-fwhm-60nm/

Looks like that Pixelteq filter may cut off at or below 400nm, and not have so much visual range violet. Yep, looks that way to me.

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These days, we have a wide range of UV-pass filter choices for reflected UV photography.

  • All of them have their own benefits and drawbacks, pros and cons.
  • I've used them all and I do not find that there is one filter choice which is superior to the others.
  • They seem to be all equally good.

Just as we select the camera or lens for the photo task at hand, we should also select the UV-pass filter or filter stack which is best for the UV photo task at hand.

 

If you like a little violet to be passed (as I often do for some subjects), you have choices. If you want to image well below violet, you have choices.

 

If you are concerned about the amount of IR-blockage, you have choices. I find OD 3.5 to be my personal boundary line, but YMMV.

 

End of discussion please. :lol: :lol: :lol:

 

Time to go make some photos.

 

Please do not rile me up. I still have 2 dental appointments to go.

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Andrea,

Which one of your children, I mean filters is your favorite?

The miss behaving Baader, whom has been droped, tripod stomped and cracked?

The new child SEU mk2 with that hint of blue?

The U340 stack with that golden light?

Or the U360 stack which is pure of IR contamination?

 

The thing is we do all have a filter preference. But its user specific or even subject specific as Andrea said. So it doesn't really matter.

Its all about the fun in the photos.

 

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I really do not have a favorite UV-pass filter.

 

If shooting non-botanicals, I usually take two or three filters, shoot with all of them and then look to see what looks "best" during photo review and conversion. If there is some minor nuance from a filter that makes one photo more appealing than another, then it is often due to the full combo of camera+lens+filter+light+subject at that time and not simply because of a few nanometers to the right or left of some arbitrary marker like 400nm.

 

The BaaderU is on the UV-Nikkor, so most of the botanicals have been photographed with that. But not all.

 

We are working in such a narrow range -- usually 350-400 nm -- that you really cannot expect much difference between the commonly used broadband filters and filter stacks.

 

So far all the broadband UV-pass filters and filter stacks sort themselves into two RAW groups: the Orange-ish Group and the Magenta/Pink-ish Group. That's it. And when false colour WB is applied a great deal of that difference goes away.

 

I do not have enough narrowband filters to make any comments. And the one which is truly narrowband (10nm with 90% transmission) is useless due to the reflection problem.

 


 

Probably the best "advice" one could give it to learn to use the gear you have really really well. Make thousands of photos. Learn from them. Practice UV photography from end-to-end: composition, lighting, technique, artistry, gear, conversion, "post-processing". A filter is such a small part of this.

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Don't forget to ask Andrea about her Baader U that was attacked by the illusive eastern garden slug.

It is one of my favorite stories, it always make me smile.

It might actually be turned into a Netflix original Halloween story ...someday maybe...

Anyway, as I remember it, after the Baader U was safely rescued, the ultimate question was, "what is the best way to clean slug goop from the Baader U".

A team of scientists are still working on this question in a special lab... somewhere...

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oh la !!! I've totally forgotten that one. I've had so many fine adventures wrecking my various filters !!

 

I probably used Eclipse on that mess. I'm sure slugs have their purpose in the scheme of things, but that does not include slime-tracking filters, IMHO.

 

Speaking of Eclipses...

 

After I accidentally stomped my BaaderU into unrepairable (and very sharp shards) in Anza-Borrego, we had driven on to Organ Pipe. On one of the loop trails, we stopped to photograph a nice array of desert blooms. I opened the back of the rented Ford Eclipse and watched my D300 + UV-Nikkor + AndreaU roll out onto the gravel road, take a small bounce and continue onward tumbling down the sides of the roadside wash in that location. Amazingly no harm was done. Sometimes the UV-gods are with us instead of against us. :lol: :rolleyes:

 

After those fun events, I learned to carry two of each filter. And to secure the gear in between stops.

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An endearing story it was, with an ongoing thread at the time, which I searched for but didn't find on fotozones.

I don't remember if it was a slug or a snail.

So the saga continued...

But I thought the old rumor was that Bjorn was the one who rolled down a hill with his new UV-Nikkor copy...

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It was a slug. It's coming back to memory a bit. :lol:

Locally, the garden slugs are more gloopy than the tiny snails we get sometimes. Thing is, those slugs don't move very fast, so how did they manage to crawl onto a filter that I had only put down just for a sec between shots? And up over the edge of that ridged Baader mounting ring!

 

In Organ Pipe National Monument, Bjørn went sliding a ways down a gravel slope while in search of a Ratany flower. IIRC, he managed to hold onto his camera/lens and it was OK, but he got a wicked scrape along one arm. Fortunately, I had packed some sterile gauze wipes and little packets of neosporin ointment, so we got his arm cleaned up ok.

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It was a slug. It's coming back to memory a bit. :lol:

Locally, the garden slugs are more gloopy than the tiny snails we get sometimes. Thing is, those slugs don't move very fast, so how did they manage to crawl onto a filter that I had only put down just for a sec between shots? And up over the edge of that ridged Baader mounting ring!

 

I think that is clear evidence that you were abducted by aliens, memory wiped and dropped down the next day. :P

 

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....hmmmm......why yes.....that must be so. Some vague foggy memory now of big eyes seems to be trying to break thru.......
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