Jump to content
UltravioletPhotography

Hello from Virginia


KaJashey

Recommended Posts

Hello from central Virginia. My name is Josh lewis but I'm going to go by the KaJashey here.

 

UV photography is something I aspire to. Poverty drives me away.

 

I have a full spectrum Nex-5 and have done some IR photography with it. I have used a cardboard box, a lens, and cyanotype paper to take really primitive UV photos. The paper is most sensitive at 360nm or so.

 

Here are my albums kind of organized as experiments. The photos often have descriptions on what I was trying to do. Here is a rushed article on the cardboard box cyanotype camera.

 

I hope to buy a UV pass filter before spring arrives.

Link to comment

Excellent work Josh, you have a new fan....

Get the Baader U.....you won't be disappointed, & save your money from not buying the cheapies first.

Col

Link to comment

Hi! Gorgeous photos there. Some interesting experiments.

 

(I still don't own a Baader, having gone the filter glass route, so it's not the only way...)

Link to comment

Excellent work Josh, you have a new fan....

Get the Baader U.....you won't be disappointed, & save your money from not buying the cheapies first.

Col

 

Thanks, I checked out your flickr work and fanned you in return.

 

I was very interested and saving for the kolari vision UV pass filter. Now after joining this forum and seeing lots of comparisons I'm interested in the Baader U. Can I ask you a few questions?

 

Can it be used alone without also adding an IR cut? The blues in sample pics are false UV? Can it be remounted in a different filter thread?

Link to comment

Welcome to UVP.

 

As to your BaaderU question, yes it can be used on its own. I do that all the time :smile: Its IR-blocking capacity, provided you use the latest versions, is sufficient even when I use my Broncolor studio flashes with uncoated Xenon tube (they are 1600 Ws units so more than ample UV output there. And visible + IR in the plenty, of course).

Link to comment
The older versions had labels "300-390nm", newer "320-380nm" on the boxes if memory serves. The very oldest had pink and greenish colour, the newer pink and golden reflections.
Link to comment

Hi, Josh. And welcome.

 

Wow, fascinating stuff you've done. I can see we're going to be learning some new stuff from you on UV & IR photograpgy: there's quite a lot of IR going on on this forum, despite it's name.

 

I echo the recommendations for the Baader U as a great general-purpose UV lens - although as you get into it I'm sure you'll be wanting to get some more specialised filters.

Link to comment

---. I can see we're going to be learning some new stuff from you on UV & IR photograpgy: there's quite a lot of IR going on on this forum, despite it's name. ---

 

Andrea and I jointly decided on opening the forum for IR photography a few years ago.Many, if not all, UV photographers tend to have interests in anything "invisible" be it UV or IR. Or something entirely else. That being said, our main thrust is, and will stay, UV. We are pragmatic admins :smile: :bee:

Link to comment

Your UV experiments look more like IR than UV to me.

 

The cheap route would be to get a 2mm thick S8612 filter and a 2mm U360 filter. With that combination you will get good UV signal and excellent IR suppression. Then latter if you want deeper UV you could add a 2mm U340 filter. Or for less deep UV add a 1.5mm thick U330 filter.

 

I have had recent luck with ordering the Chinese ZWB1 filter. The two I recently got were 1.9mm thick. But that can be hit and miss and might be a complete waste of money.

 

My first UV filter purchased back in 2008, was the Baader venus U filter. Its still my favorite UV filter. The contrast is the best. And yes you can use it all by its self for almost all cameras. Exception being my Sigma SD14, which is so IR sensitive, it can pull out some IR leakage in sun light. But very few people use Sigma Foveon sensor cameras.

 

 

 

Link to comment

I second David's recommendation above about the stacks with a S8612, 2mm.

The S8612 + U-360 is my favourite for images looking similar as from a Baader U.

 

That stack has a better IR-suppression than the Baader U I also have. (It is the latest version with the better IR suppression)

I have sometimes seen a tiny bit of IR leakage in pictures taken with my Baader filter.

That is why I stopped using it.

 

The only advantage the Baader U have is a better transmission.

The Baader U is expensive and rather thin and frail, beside the risk of UV-leakage.

Several members here have accidentally broken or cracked their filters.

It is also a dichroic design that will give colour shifts in the corners of the image if used on wide angle lenses.

 

If the highest transmission is the most important characteristic and you can live with all the other potential disadvantages, it is a very high quality filter.

Very high transmission can sometimes be important, but normally exposure times get quite long even with a Baader U.

 

If you value the flexibility and ability to later try other filter combinations instead, go for the S8612, 2mm based stack.

That is how I like to work.

 

If you value a slightly higher transmission than the stack of separate filters can give you, and just want your images to look like from a Baader U, there are specially UV-glued stacks. They will increase the exposure time by around 30% compared to a Baader U.

 

IMHO this is the best alternative for that path: https://www.ebay.com...hy/303389413241

The seller is a member of this group, but I have no affiliation to him except as a very satisfied customer.

I have bought from him several times and the quality of the filters and service has always been very high.

Link to comment

... I have sometimes seen a tiny bit of IR leakage in pictures taken with my Baader filter. ...

 

Hmmmm.

 

I switched from a (U340+S8612) stack to Baader U for general UV work because the Baader seemed to give crisper images and was almost 1 stop faster, and I never noticed any hint of IR leakage.

 

However, following your post I tried stacking the Baader with an R72, and indeed I could see a faint image. If I stacked (U340 + S8612 + R72) I could not see anything at all. So you are right.

 

If I stack (Baader + S8612 + R72) I don't see anything either. (Baader + S8612) was about 1/2 stop faster than (U340 + S8612).

 

So I think I'll do some testing to compare Baader vs. (Baader + S8612) vs. (U340 + S8612) to see if I can detect any differences in the final result.

Link to comment

Don't know, Col,

 

The reflections are pink and greenish-gold (or goldish-green), which makes it sound like the older model from Birna's description even though I bought it only last May. But ...

 

The filter mount says "CWL 350nm" and gives the model number 2458291. The box says 320-380nm - which according to Birna is the newer model.

 

Anyway, about to go and do a test. I'll let you know ...

Link to comment

The IR leakage of the Baader is mainly an issue if you shoot at night or otherwise have bright IR sources (such as incandescent lights) in your image. That said, it comes in only one size, which can limit which lenses may be used with it. Other filter stacks are available in a range of sizes. If you have multiple lenses, one can get by with just one filter and a series of step-up rings, as long as the filter covers the largest lens.

 

Due to its coatings, the Baader is less prone to surface corrosion than the others, and that phenomenon is a definite nuisance both with UG-type filters and with BG-type glass.

Link to comment

... That said, it comes in only one size, which can limit which lenses may be used with it. ...

 

Well, actually it comes in two sizes, and the 2" (48mm mount) size fits all the lenses I have for UV, from 28mm to 105mm. No vignetting with the 28mm (and APS-C sensor), and I haven't noticed any wide-angle problems (although I haven't used the 28mm very much and am not quite sure what I would expect to see in a UV shot).

 

Anyway, here are my test results. It's of a snowdrop, which are one of the few flowers about in the UK at the moment. The UV shots are all White Balanced for the Baader U. You can see a faint image on the Baader U + R72 shot when looking at the original, which would be the IR leak through the Baader. But it's very, very faint. The main thing to compare would be the Baader U vs. (Baader + S8612), as the second of these would have the IR leakage blocked: I can't spot any difference

 

Light source was 4 x de-lensed WS560 flashguns.

 

Visible:

post-245-0-99931400-1580663585.jpg

 

Left: Baader U, and Right: Baader U + R72 (same exposure as Baader U):

post-245-0-37686300-1580663596.jpg post-245-0-21638000-1580663625.jpg

 

Baader U + S8612 (1/3 stop more exposure than Baader U):

post-245-0-23448900-1580663613.jpg

 

U340 + S8612 (1 stop more exposure than Baader U):

post-245-0-31539600-1580663636.jpg

Link to comment

The IR leakage of the Baader is mainly an issue if you shoot at night or otherwise have bright IR sources (such as incandescent lights) in your image. That said, it comes in only one size, which can limit which lenses may be used with it. Other filter stacks are available in a range of sizes. If you have multiple lenses, one can get by with just one filter and a series of step-up rings, as long as the filter covers the largest lens.

 

Due to its coatings, the Baader is less prone to surface corrosion than the others, and that phenomenon is a definite nuisance both with UG-type filters and with BG-type glass.

One bright IR source is reflection of living foliage.

The occasions I saw the problems with IR-contamination was in bright daylight. The contamination affected really dark UV-signatures in flowers.

 

One possible reason to my problem is that I am rather far north on the globe (55°), even if I'm in the southern part of Scandinavia.

In America that is similar to Newfoundland or the southern tip of Alaska. At these latitudes there are less UV than in North Carolina or Virginia.

 

I have seen almost no surface corrosion during the three years I have had my filters, but then we normally have less humidity and heat here too. I think humidity and elevated temperatures increase the speed of that corrosion.

Link to comment

Well, actually it comes in two sizes, and the 2" (48mm mount) size fits all the lenses I have for UV, from 28mm to 105mm. No vignetting with the 28mm (and APS-C sensor), and I haven't noticed any wide-angle problems (although I haven't used the 28mm very much and am not quite sure what I would expect to see in a UV shot).

 

Anyway, here are my test results. It's of a snowdrop, which are one of the few flowers about in the UK at the moment. The UV shots are all White Balanced for the Baader U. You can see a faint image on the Baader U + R72 shot when looking at the original, which would be the IR leak through the Baader. But it's very, very faint. The main thing to compare would be the Baader U vs. (Baader + S8612), as the second of these would have the IR leakage blocked: I can't spot any difference

 

Light source was 4 x de-lensed WS560 flashguns.

 

Those flowers will not show any of the leakage.

You need something really UV-black and I don't think you'll find anything suitable outdoors now.

Also, flashguns can have a rather strong UV concealing the problem.

 

Try again when the Lesser celandine appears, preferably a warm afternoon when the sun is a bit low.

https://en.wikipedia.org/wiki/Ficaria

Link to comment

Not sure I've seen any lesser celandine around here.

 

I'm waiting for daffodils and snapdragons - when I've photographed then in UV before parts of them come out very dark, and I guess like most flowers they'll be white in IR. So they may be a good test. I also want to try using the tri-colour UV technique on them to see if there's any UV colour in what the Baader U records as black.

 

post-245-0-06012000-1580665898.jpg

 

post-245-0-89186800-1580665908.jpg

Link to comment
  • 1 month later...

Your UV experiments look more like IR than UV to me.

 

The cheap route would be to get a 2mm thick S8612 filter and a 2mm U360 filter.

 

I think your right about the experiments being mostly IR. Thanks for the advice on the filter stack. This may be the way I have to go.

Link to comment

... I'm waiting for daffodils and snapdragons - when I've photographed then in UV before parts of them come out very dark ...

 

post-245-0-89186800-1580665908.jpg

 

That snapdragon is really interesting I wonder how much of that UV darkness is protective for the developing seeds.

Link to comment
  • 2 weeks later...

That snapdragon is really interesting I wonder how much of that UV darkness is protective for the developing seeds.

 

Hi, KJ. Been away so only juat aeen your message ...

 

Still awaiting a snapdragon to play with. I have used the tri-colour technique on a daffodil, bd that turned out to be disappointing - very little UV colour at all. So I hope the snapdragons don't let me down.

Link to comment
  • 2 months later...

If you value a slightly higher transmission than the stack of separate filters can give you, and just want your images to look like from a Baader U, there are specially UV-glued stacks. They will increase the exposure time by around 30% compared to a Baader U.

 

IMHO this is the best alternative for that path: https://www.ebay.com...hy/303389413241

The seller is a member of this group, but I have no affiliation to him except as a very satisfied customer.

I have bought from him several times and the quality of the filters and service has always been very high.

 

I wound up going this way. I hope that by getting a cemented stack I don't have the visual problems that would come with two filters. Thank you for the suggestion even if it wasn't yor first recomendation.

 

I've done my first couple UV photos earlier in the day. Now I'm trying to white balance them and consider how to take better photos tomorrow.

 

On white balance a few members highly regard Photo Ninja, I can see why are there other raw developer that have a similar edge regarding white balance? Adobe, Rawtherpy, Lightzone all couldn't do white balance as good as photo ninja. I get the feeling I would just be downloading and trialing a bunch of software to get as good if that.

 

Is there a better place for my UV noob questions than here in the introductions?

Link to comment

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
×
×
  • Create New...