Thinking about Andrea U mkII filter

[Doug A]

Thought I wanted a Hoya 360U + Schott S8612 stack. Ran across an @Andrea B post from 2016 showing that combo lost a whole stop of light vs the Andrea U mkII. That is as much as the camera conversion gained. The example pictures looked pretty close to the Baader U examples. The mkII would also work with wide angle lenses. But, I don't see many people using this filter. Am I making a mistake.

 

Thanks,

Doug A

[Andy Perrin]

I think the Andrea U mkII is a faster filter that shifts the peak towards visible light by a lot, with the result that you get faster exposure but may have to play with the colors to see the yellows/oranges, and re-reading the old 2016 post, Andrea herself said it tended to be overly greenish. I see that Andrea added a 2021 note that Reed has made some further changes to the filter, so the results might be different now? Baaders tend to produce the best balanced colors. Hoya 360U + Schott S8612 is probably in between?

 

I think there was a tiny bit of visible light "contamination" >400nm, with the old mkII version, so depending on how much of a purist you are about "UV" photos, that might weigh into your considerations. But maybe this has been adjusted in the new mkII???

 

So basically, I don't think it's a MISTAKE but it's definitely a choice to prioritize exposure over color balance.

[Andrea B.]

There has been more than one version of the AndreaU. And I have lost track of them, I'm sorry to say, and I do not know why the versions changed. The original AU I had and used in 2013 was quite blue. But the two I have now are not.

 

The currently advertised AU MK-2 is non-dichroic and approximately 360bp37. It appears to have a toe over 400nm which is not uncommon and scarcely makes a difference to UV signatures, IMHO. The BaaderU has a tiny blue violet toe itself as do some stacks. I happen to like this kind of UV-pass filter and specifically bought a MoonU with that property. The earliest AndreaU (mine n 2013) had a fat blue violet toe, but that version is long gone. 

 

Looking at the chart for the AU MK-2, I see it has a nice high transmission rate with more transmission between 360-380 nm than between 340-360 nm. This would slightly alter false colours towards the blue, perhaps - depends on the subject and the light. 

 

********

 

I need a link to my 2016 post!! 

[Andy Perrin]

Link!

https://www.ultravioletphotography.com/content/index.php?/topic/1977-filter-test-andreau-mk-ii-with-bu-seu-u-360-bouquet-in-raw-false-colours-and-in-wb/

 

Maybe Reed will weigh in with some pics from the new one?

[Andrea B.]

Thanks, Andy. I reviewed the link. That was a nice test I ran there!! It does illustrate well the difference in the raw colors between the BaaderU and AU.

I noted in that topic that the AU which I tested in 2016 had a 65% transmission peak. The current AU-2 chart shows a 75% transmission peak.

 

I used the word "blue" in my comment above. I should have written "violet". So I'll go back and change that. 

 

[Andy Perrin]

Honestly, it sounds like we need a redo of this test. It’s hard to give people good advice when we don’t know how the current version performs. The difference from the Baader and the Hoya stack may be much smaller now. 

[Andrea B.]

I don't think I have the latest AndreaU-2.

[Andy Perrin]

How can you, Andrea, not have the AndreaU-2? That’s like if What’s on First!

[Andrea B.]

Misread.

 

I have *an* AndreaU Mk-II. But I don't know if I have the most recent version or not. I'll try to look to see if I have any receipts somewhere. That move 2 years ago totally upheaved all my records and papers which are now scattered hither & yon in folders & unpacked boxes.

 

[Doug A]

8 hours ago, Andrea B. said:

Misread.

 

 I'll try to look to see if I have any receipts somewhere. 

 

I appreciate the offer, but please don't waste a lot of your valuable time on this. 

 

I'm trying to decide:

 

1. Do nothing at the moment and use the Igoriginal filter stack I already have.

2. Buy Baader U for teles and use Igoriginal stack on the Igor 35mm wide angle.

3. Get the Andrea U mkll and use it for everything.

 

Think I've ruled out the Hoya U360/ Schott S8612. Too much light loss for sea level use. Having enough UV light has been the biggest obstacle. 

 

My worry is @Andrea B.has the AU mkll and rarely seems to pick it over the Baader U.

But, wouldn't both U filters outperform my Igoriginal Chinese ZWB 1 (2mm)/ BG39 (2.3mm) filter stack? 

Thanks,

 

Doug A

 

 

[Andy Perrin]

Doug, I think you are overestimating the exposure difference between the Hoya/Schott stack and the others. They are probably all within about 1 stop of each other. If you are imagining that you will be shooting good noise-free photos while walking around without a tripod using ANY of these, that is simply not gonna be the case. The options are handheld high ISO photos vs. good quality pics on a tripod (in sunlight). Having one stop more light will help but it’s not enough to overcome the general dimness of solar UV. 
 

It’s important to understand that the manufacturers supply LINEAR graphs but the camera sees LOGARITHMICALLY in stops, so the linear graph might show a filter that looks like it has a peak that’s 50% of the Baader’s but that’s actually just 1 stop slower. 

[Andrea B.]

Doug, for the botanicals I most often use BaaderU because that is the only UV-pass filter available when I started out years ago. It was also the UV-pass filter which my mentors Birna and also Klaus and Vivek used at that time. So while it is true that you see my use of the BaaderU quite a lot here on UVP, please know that it is not the only UV-pass filter I use.*

 

In the winter in the Midwest it is true that you are lacking UV light. Winter is a problem for *everyone* in reflected UV photography. I don't know what you are currently wanting to photograph, but if it is winter and you are using a UV-pass filter, then you must use a tripod in order to keep ISO settings low. This is true even when using one of the (so-called) "faster" UV-pass filters. So minor differences in exposure times are irrelevant when on tripod.

 

One benefit of a filter like the AU is that it is coated and requires less maintenance. And of course, as you know, it will work better on wide angle lenses because you won't get that dichroic discoloration although vignetting is still possible.

One benefit of a stack is that the S8612 can be reused with other glass. Like someday you might want to try the UV+blue+green offered by UG5 glass. Just one example.

 

If you bought a filter like the AU, the  is likely true that a coated, name-brand filter has a bit more resale value than a stack due to maintenance issues over time. On the other hand, there really are not a lot of reflected UV photographers "out there" to sell a used UV-pass filter to. Most folks try it out for a couple of years and then lose interest.

 

*Some things in life are the way they are because of what I call "historical accident".

[dabateman]

3 hours ago, Doug A said:

I appreciate the offer, but please don't waste a lot of your valuable time on this. 

 

I'm trying to decide:

 

1. Do nothing at the moment and use the Igoriginal filter stack I already have.

2. Buy Baader U for teles and use Igoriginal stack on the Igor 35mm wide angle.

3. Get the Andrea U mkll and use it for everything.

 

Think I've ruled out the Hoya U360/ Schott S8612. Too much light loss for sea level use. Having enough UV light has been the biggest obstacle. 

 

My worry is @Andrea B.has the AU mkll and rarely seems to pick it over the Baader U.

But, wouldn't both U filters outperform my Igoriginal Chinese ZWB 1 (2mm)/ BG39 (2.3mm) filter stack? 

Thanks,

 

Doug A

 

 

 

 

An other option is to buy a flash cord, add a Canon 199A to the end of it. Careful just remove the two screws holding the front in place and pull out the fresnel.  Add a clear piece of PMMA or a good cut clear CD case piece cut to the size of the fresnel just removed that doesn't absorb UV. 

That will give you many more UV stops than any filter combination. You might even want to wrap 2 layers of plumbing tape around the clear PMMA you place infront of the flash to act as a diffuser. 

[Doug A]

@Andy Perrinagree one full stop isn't a lot. But, it does mean using the Nemo UV focusing torch less in live view. 

 

Thanks for the clarification and info @Andrea B.Not sure what I'll shoot this winter. Probably landscapes and indoor stuff, including store bought flowers. Winter is also a good time to learn more about photo editing. 

 

Using a tripod is fine, and it is probably all that is needed for winter landscape shooting. Thinking ahead to spring, a brighter filter would improve my "keeper" rate. A tripod helps with flowers, but doesn't stop wind motion. Unfortunately, the brightest UV light tends to be when there is the most wind. Waiting until day's end, for less wind, doesn't seem to work as well for UV. 

 

 Resell value rarely matters. I tend to keep stuff. Too lazy to sell things. When I do sell something, I often need it later. Haven't used the darkroom in 20 years and almost sold the equipment. Now I'm using the El-Nikkors for macro and UV. 

 

 

@dabateman  you are psychic! Modified an old Vivitar 283 yesterday for full spectrum. Want to see if it puts out more UV than the modified Pentax 540. Today I tried the@Andrea B. 3 pop flash technique. It worked well .

 

Thanks,

Doug A

 

 

[Andy Perrin]

Doug, I can see just fine in the live view if I turn the ISO up while focusing and then back down for shooting - no torch is really needed although I know some people do it that way.

 

Quote

 Thinking ahead to spring, a brighter filter would improve my "keeper" rate. 

I don't think you will find this to be true. Wind is always a problem, regardless of what filter or stack you use. What improved the keeper rate for me was getting a camera body which lets me increase the ISO without adding too much noise. On the A7S, I can use up to 3200 or so with essentially no additional noise, and up to the 10000 range with a little noise. That's a LOT of stops, not just one. Also, get a flash.

 

I think you should choose a filter more based on which false colors you like best. Check out Andrea's new test!

[Doug A]

@Andy Perrin good point about high ISO and live view.  Pentax K-1 has the same Sony sensor as the Nikon D810, so it is pretty good at high ISO. I have a button customized to give 2 stop light boost on the screen. For everything but extreme macro, no torch is needed for focusing. But, this late in the season, most of the outdoor flowers are small. Largest are dandelions. Some of the others are 1/4 that size. With the El-Nikkor 135 I'm using 8" of bellows + 3 extension tubes. That's a hefty light loss. After setting the desired composition and focus, I hate to touch the rig. I get more keepers using the torch and leaving aperture and ISO alone. For landscapes I rarely need to boost ISO above the photo requirement. 

 

I now have two flashes. Need to fine tune the set up.  It is a little cumbersome at the moment. 

 

Thanks,

Doug A

[Andy Perrin]

Wow, that is a loooong tube you are shooting through. I see why you need a torch for that, but I do think the flashes are going to make the biggest difference to your life.