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First impressions of UG2A, 1mm

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#1 UlfW

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Posted 09 June 2019 - 14:20

I want to share my first impressions of the UG2A, 1mm

My curiosity has been aimed at using this filter form macro and flowers, stacked with my S8612, 2mm the same way as I did with the UG2A, 2mm.

Camera and lens: Canon 60D full spectrum modified, El-Nikkor 80/5.6 metal.
The images are screen shots from my FastRawViewer, without any saturation adjustments, only white balance, exposure and contrast adjustments are done to taste.
Shooting date 2019-04-07, afternoon, ca 15.00 @ 55°N (not much UV in the sunlight)

I think the motif flower is a lesser celandine https://en.wikipedia...i/Ficaria_verna
Attached Image: Screen Shot 2019-06-08 at 14.14.18.png
VIS BG40

S8612 + UG2A, 2mm - beside - S8612 + UG2A, 1mm
Attached Image: Screen Shot 2019-06-08 at 14.16.29.png Attached Image: Screen Shot 2019-06-08 at 14.16.07.png

Compared to two more usual stacks:
S8612 + U-360, 2mm - beside - S8612 + UG5, 1.5mm
Attached Image: Screen Shot 2019-06-08 at 14.16.53.png Attached Image: Screen Shot 2019-06-08 at 14.15.19.png

My impression is that the UG2A is an interesting addition to my filter collection for UV-B,G type of images.

Edit: Added shooting date, time and longitude

Edited by UlfW, 10 June 2019 - 10:25.

Ulf Wilhelmson
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#2 Cadmium

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Posted 09 June 2019 - 15:11

Are you sure you didn't get the 'bee vision' shots mixed up?
Because the one with the darker green center is what UG5 1.5mm + S8612 2mm looks like. For UG5 1.5mm + S8612 2mm to have a washed out green like your example shows there is not right.
UG5 1.5mm + S8612 should be the one that has the darker green, and UG2A 1mm + S8612 2mm should be the one with the washed out lighter green.
The comparison makes no sense to me.

Of course, there is that one little UG2A 1mm transmission blip in the 560nm range, but...?
I will have to test it, but there is definitely something not right about your UG5 1.5mm + S8612 2mm shot, there is something just plain wrong with that.

Edited by Cadmium, 09 June 2019 - 15:16.


#3 UlfW

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Posted 09 June 2019 - 16:06

View PostCadmium, on 09 June 2019 - 15:11, said:

Are you sure you didn't get the 'bee vision' shots mixed up?
Because the one with the darker green center is what UG5 1.5mm + S8612 2mm looks like. For UG5 1.5mm + S8612 2mm to have a washed out green like your example shows there is not right.
UG5 1.5mm + S8612 should be the one that has the darker green, and UG2A 1mm + S8612 2mm should be the one with the washed out lighter green.
The comparison makes no sense to me.

Of course, there is that one little UG2A 1mm transmission blip in the 560nm range, but...?
I will have to test it, but there is definitely something not right about your UG5 1.5mm + S8612 2mm shot, there is something just plain wrong with that.

Yes, I am absolutely sure there is no mixup! I trust you have marked the filters correctly. ;-)
I shoot very controlled with a fixed sequence of filters from a filter magazine, to avoid mixups.
I have shoot several other flowers with the same outcome.

This is my current sequence:
Attached Image: IMG_1806.JPG

These filters with my camera/lens setup give this result.
Have you tried the UG2A + S8612 on some flowers or is your reaction just based on theories?

The green response varies with different flowers. This is not a Rudbeckia.
I have seen more strong green in other flowers.
Possibly also with the UV/ VIS light ratio can change the outcome.

Edited by UlfW, 09 June 2019 - 16:09.

Ulf Wilhelmson
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#4 Andy Perrin

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Posted 09 June 2019 - 17:09

Now I want a magazine like that. My filters are going everywhere these days.

#5 Mark

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Posted 10 June 2019 - 00:35

I agree - that filter magazine looks great. Unfortunately my filter are many different sizes and formats.

#6 Cadmium

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Posted 10 June 2019 - 00:39

Well, your not doing something right then. Because I just tested the two stacks, and it is the other say around for me.
UG5 (or U-330) 1.5 + S8612 is the classic 'bee vision' stack, gets the best results using those thicknesses, and the green is much richer and darker with the UG5 1.5mm stack than with the UG2A 1mm stack.
The UG2A 1mm stack still has some green, but is no where near as rich and obvious as the UG5 stack.
Your UG5 1.5mm stack is washed out and something is wrong with how you did that. The green should look much better, and better than the UG2A.
That is a terrible example of a UG5 + S8612 stack. It hardly shows any green, and it is the optimal UV+Blue+Green stack.
So something is wrong.

Edited by Cadmium, 10 June 2019 - 00:41.


#7 Cadmium

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Posted 10 June 2019 - 01:04

Here is a quick comparison between UG2A 2mm and UG2A 1mm, used as dual band IR filters, each alone, not stacked with anything.
The 1mm thick version has a lighter more violet sky than the 2mm thick version.

UG2A 2mm thick
Attached Image: UG2A_2mm_800.jpg

UG2A 1mm thick
Attached Image: UG2A_1mm_800.jpg

Edited by Cadmium, 10 June 2019 - 05:00.


#8 UlfW

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Posted 10 June 2019 - 03:08

View PostAndy Perrin, on 09 June 2019 - 17:09, said:

Now I want a magazine like that. My filters are going everywhere these days.
It is an ongoing project from last summer, when I got my 3D printer.
It is printed from ABS in three different types of sections. Inner walls,
and two types of end sections. All kept together with three long threaded round spacers.
I am happy to share the 3D models if someone is interested.
Ulf Wilhelmson
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#9 UlfW

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Posted 10 June 2019 - 03:36

View PostCadmium, on 10 June 2019 - 00:39, said:

Well, your not doing something right then. Because I just tested the two stacks, and it is the other say around for me.
UG5 (or U-330) 1.5 + S8612 is the classic 'bee vision' stack, gets the best results using those thicknesses, and the green is much richer and darker with the UG5 1.5mm stack than with the UG2A 1mm stack.
The UG2A 1mm stack still has some green, but is no where near as rich and obvious as the UG5 stack.
Your UG5 1.5mm stack is washed out and something is wrong with how you did that. The green should look much better, and better than the UG2A.
That is a terrible example of a UG5 + S8612 stack. It hardly shows any green, and it is the optimal UV+Blue+Green stack.
So something is wrong.
I do not understand why are you attacking me or my process.
We might see different results.
Let us find out the reason for that instead of insisting that something is wrong. OK?

The final images are shaped by many different components, not only the filter.
[Light source spectrum] x [ motif reflectance spectrum] x [filter transmission spectrum] x [camera sensitivity spectrum] x [processing by software of the RAW-file]
Each of these affect the result and I think the only common one here in our different processes is the filter transmission. There is no right or wrong.

It is very interesting and surprising that you see the opposite response of the UG5-stack compared to the UG2A-stack.
I will come back later and try to explain how I think this works and why the different stacks give these results I see.
Ulf Wilhelmson
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#10 Cadmium

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Posted 10 June 2019 - 04:16

I strongly discourage anyone here from choosing UG2A 1mm + S8612 2mm for UV+Blue+Green ('bee vision') stacking over UG5 (U-330) 1.5mm + S8612 2mm.
You can search the typical results for UG5/U-330 stacks on this board, and find many good examples of the typical 1.5mm + 2mm stack. I fully recommend that stack for that purpose.
I am not attacking you Ulf, I am just totally disagreeing with that result and especially that comparison, because it makes the UG2A stack look like what the UG5 stack looks like.
I disagree with that result. I don't want people to get the wrong idea.

As I said, there are plenty of other examples of UG5 and U-330 2mm, 1.5mm, and even 1mm stacked with S8612 for UV+Blue+Green,
but here are a couple of the older more original examples.

http://www.ultraviol...e-filter-stack/

https://www.ultravio...marsh-marigold/

Edited by Cadmium, 10 June 2019 - 05:00.


#11 UlfW

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Posted 10 June 2019 - 05:31

View PostCadmium, on 10 June 2019 - 04:16, said:

I am not attacking you Ulf, I am just totally disagreeing with that result and especially that comparison, because it make the UG2A stack look like what the UG5 stack looks like.
I disagree with that result. I don't want people to get the wrong idea.
Steve, - As you have no information at all about anything except the filter, you lack facts to know the reason for the difference.
The difference is what you base the disagreement on.

I try to look at this from a positive side instead, being curious, trying to understand the reasons for the difference.
I encourage anyone that already have a UG2A, 1mm and S8612 to try that combination with suitable flowers and show the results.
I also encourage others to get more different filters exploring their possibilities.
The results will differ for different light situations, cameras and processing!
The difference is the interesting thing, asking for an answer.

Seeing the result caused by different filters is interesting and the outcome varies from situation to situation.
There is no fixed truth that UG5 (U-330) 1.5mm + S8612 2mm is always the only solution for UV+Blue+Green.

I like to explore the results from different filters and often get surprised, not seeing what I expected.
For the same motif I often go through 10-15 different filters to see how that particular flower respond in that light situation to each filter.
This is quite interesting for me and I would like to not being alone with doing this.

I have indeed seen saturated green UV-signature responses for some flowers with UG5 1.5mm + S8612 2mm.

Edited by UlfW, 10 June 2019 - 05:31.

Ulf Wilhelmson
Curious and trying to see the invisible.

#12 Cadmium

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Posted 10 June 2019 - 05:35

Ulf, I have used the UG5 1.5mm + S8612 2mm stack enough to know what I am talking about. And your example is not a good example of that stack, or what people should expect from it.
Nuf said.

#13 UlfW

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Posted 10 June 2019 - 05:52

View PostCadmium, on 10 June 2019 - 05:35, said:

Ulf, I have used the UG5 1.5mm + S8612 2mm stack enough to know what I am talking about. And your example is not a good example of that stack, or what people should expect from it.
Nuf said.
The flower or light situation might not be a good example for UG5 1.5mm + S8612 2mm stack.

I would be very interested in seeing a comparison between the UG5 1.5mm + S8612 2mm stack and the UG2A 1mm + S8612 2mm stack with your gear on a suitable yellow flower with an UV-signature.
Can you please do that test?
I just want to understand the reason for the difference.
Ulf Wilhelmson
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#14 Cadmium

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Posted 10 June 2019 - 08:13

Ulf, Maybe try 2 + 2 and see how it looks for you, could be your camera, but it still makes no sense that UG2A is darker green.

#15 UlfW

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Posted 10 June 2019 - 09:00

View PostCadmium, on 10 June 2019 - 08:13, said:

Ulf, Maybe try 2 + 2 and see how it looks for you, could be your camera, but it still makes no sense that UG2A is darker green.

2 + 2 ??

Sorry, but I disagree here and say that it actually makes sense, at least for me.
Think like this:
Additive light painting on the UV-dark or UV-black background.
Painting at the UV-signature pattern that normally is dark with a filter like Baader U.
The ratio of UV / VIS is important as that defines the general darkness of the UV-mark.

Both filters add some light from parts of VIS on the UV-image.
Less light added to dark/ black => darker

The UG2A has less transmission and a more horisontal curve until green ( ≈ 550nm), compared to UG5
More horisontal curve => more pure colour as green will dominate more

Attached Image: Screen Shot 2019-06-10 at 10.37.50.png
Attached Image: Screen Shot 2019-06-10 at 10.38.26.png

My images are from early april and it was much less UV in the sunlight then and it might be that the flower had a less pronounced UV-mark.
I am 11° further to the north (ca 1000km) compared to your location and that means much less UV, especially early in the year.

I have gotten darker green results in the mid of the summer (more UV) with other flowers and the UG5-stack.
Ulf Wilhelmson
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#16 UlfW

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Posted 10 June 2019 - 09:09

2 + 2. Ah now I understand. I have that image and more of UV+B+G.
Now you are poking at Pandora.
I'll be back. https://www.youtube....h?v=WgPePk3kGZk
Possibly not today.
Ulf Wilhelmson
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#17 SteveE

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Posted 10 June 2019 - 17:14

As I have a 3D printer that is currently waiting to be assembled, I would be very interested in your 3D models for your filter magazine
- Steve

#18 Cadmium

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Posted 11 June 2019 - 00:17

I am not poking at anyone.
2 + 2 is not the answer, and it is not what I use or what I recommend as the best 'sweet spot' stack for UV+Blue+Green ('bee vision').
Years ago I started with the 2 + 2 stack, but as Boon pointed out to me, the 1.5mm + 2mm looks best and is more technically correct for that range of transmission.
Use whatever thickness you like best, but 1.5mm is what I call best, and 2mm works also. UG5/U-330 1mm will get red in the mix.
I did these shots yesterday afternoon. I didn't think they were good enough to show, given no tripod, hi ISO, size of the flower, distance from the flower, and hand held...
I only did them to compare for myself quickly, but I can't find any better flower to show, and I don't have much time to repeat the test soon, and I think this shows enough to make sense of.
The first crop of dandelions are nowhere to be found now, there will be more in a month or so, but this is the only flower I could find around here that has the correct color pattern for this test.
This flower is very small, about 10mm in diameter.
D7000, Kuribayashi 35mm @ f/3.5, shot hand held, ISO 3200.
Strong intermittent wind, and dancing light, but flower was in a stable spot of lighting for each shot.
So these tests are fairly crude, but they make perfect sense to me.
You see the typical green flower center and turquoise/green background colors with the UG5 and U-330 1.5mm stacks,
but the UG2A 1mm stack shows very little green, and more violet in the background than the other stacks,
and the flower center, if any green is detected there at all, is much more monochrome, or dark gray/green.
There is no post processing with these, only CNX2 white balance.
Also, please make no judgments between the UG5 and U-330 stacks, any difference between those are simply changes in conditions between shots, those both work the same in my opinion.

Attached Image: UG5_1p5_U330_1p5_UG2A_1mm_x_S8612_2mm_Stacks.jpg

The shots above are UG5 1.5mm, U-330 1.5mm, UG2A 1mm (all stacked with S8612 2mm).
The Shots below are UG2A 1mm, UG2A 2mm, UG5 1.5mm (all stacked with S8612 2mm).

Attached Image: UG2A_vs_UG5_CC_1280.jpg

Edited by Cadmium, 11 June 2019 - 02:31.


#19 Cadmium

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Posted 11 June 2019 - 04:14

Green Wavelength: 495–570 nm
Attached Image: UG2A_2mm_UG2A_1mm_UG5_1p5mm_x_S8612_2mm_All.jpg

Edited by Cadmium, 11 June 2019 - 04:16.


#20 UlfW

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Posted 11 June 2019 - 06:51

OK, Get it. You can only accept the combination you tried before as optimal
In your opinion the 'sweet spot' stack for all flowers and light situations is always the UG5/U-330, 1.5mm + S8612, 2mm.
1mm and 2mm versions of those UG filters might be acceptable, but are not optimal.

I am interested to know how the UG5/U-330, 1.5mm + S8612, 2mm is more technically correct for that range of transmission.
How is technically correct for that range of transmission defined?
Is that information something you'd like to share?

In your last test above you could have included the UG2A, 1mm-stack.
It could have been interesting to hear your opinion of that stack after actually trying it.

In my opinion the UG5/U-330, 1.5mm + S8612, 2mm is not always optimal!
I do not know how often it is true. It might be true more or less often.

I strongly suspect that the ratio of UV and VIS affect the outcome. This ratio varies with time of the year and latitude.
I definitely know that a thicker filter of the same type give a darker more pronounced green effect with the same post processing of the RAW-file.
I also know that some flowers have stronger and some have weaker UV-signatures. The strength varies between individual flowers and also where they grow.

I have used your " 'sweet spot' stack" most for 'bee vision' because those filters were some of the first I bought from you. Many times they worked quite well, bur not always.
I can post examples of many different flowers to show when they worked well.

When the result was not as expected with the UG5, 1.5mm, I started to look for alternative filters to try.
Now I have seven different filters that can be used with S8612 to give some kind of UV-B G 'bee vision' effect. I have bought four of them from you, Steve.
The UG2A was the last exiting addition that happened to work very well in early april for the flower I posted first in this thread.
I have too little experience with the UG2A-stack to yet have seen any problems with it. That will likely happen in the future.
I see the UG2A 1mm as an interesting complement to other bees vision stacks, not a replacement to the UG5, 1.5 or 2mm.

My message to others: There is not one filter combination that is always optimal. The result depend on more than just the filter type.
The Steve-approved stack is likely a very good starting point for a bees vision stack, but there are other combinations that sometimes will work better.
It is interesting to explore filters and filter combinations. Not only for 'bees vision'-type of images.

My recommendation to those that want to explore beyond the limited strict official "facts" is to get more different filters and see the results yourself.
Be prepared to sometimes get disappointing results, not as expected, just as I sometimes did with my original bees vision stack.

This is a bit surreal.
I am promoting purchase and exploration of many different new filtes and it feels like Steve is fighting that idea.
Could be a language thing. No offence intended.
I have no affiliation with Steve and his company except as a customer.

Edited by UlfW, 11 June 2019 - 11:36.

Ulf Wilhelmson
Curious and trying to see the invisible.