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[Filter Test SEU Gen2 #11] A Fascinating New Rudbeckian View


Andrea B.

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[Filter Test SEU Gen2 #1] Introduction to the SEU Gen2

[Filter Test SEU Gen2 #2] White Balance, Raw Histogram & Andrea's "White Signature"

[Filter Test SEU Gen2 #3] Filter Speed & A Windy Bull's-eye

[Filter Test SEU Gen2 #4] Dealing with the Usual Dichroic Effects

[Filter Test SEU Gen2 #5] Landscape Interlude

[Filter Test SEU Gen2 #6] Monochrome Museum Comparison

[Filter Test SEU Gen2 #7] Measured Filter Transmission

[Filter Test SEU Gen2 #8] Dichroic Reflection Detour

[Filter Test SEU Gen2 #9A] Longpass Stack Wandering Discussion. See #9B for results.

[Filter Test SEU Gen2 #9B] Longpass Stack Results

[Filter Test SEU Gen2 #10] What good is a filter test without a Rudbeckia?

[Filter Test SEU Gen2 #11] A Fascinating New Rudbeckian View

[Filter Test SEU Gen2 #12] Summary


 

 

Seeing the Rudbeckia between 370-400 nm

 

I wanted to try a test of the SEU Gen2 in UV-scarce light. So I made an indoor, non-flash close-up photo of the Rudbeckia from the previous test #10. The only UV light to reach the flower was from the foggy, overcast outdoor light coming in through the sliding glass doors.

 

In order to show the the SEU Gen2 is a faster filter under such conditions, I paired it with the BaaderU, another dichroic filter. It turned out to be an interesting pairing as you will see.

 

Shooting in dull, low light with no supplementary flash does not always provide adequate contrast in a photo. Such was the case here. But that is why we have good converters to help us restore a bit of global contrast when needed.

 

We become accustomed to a particular UV view when using the same UV-pass filter for years. But a common question is whether or not "things look different" when using a UV-pass filter with a different UV transmission peak. And now I have an excellent illustration below showing that indeed sometimes things are different. I was absolutely delighted to see the different tonalities in the next two UV photos. They are presented in Black & White to emphasize the tonal differences.

 

The SEU Gen2 with its emphasis on UVA between 370-400 nm gave me an entirely new view of the common Rudbeckia UV-signature than the one I had always seen using the BaaderU or other UV-pass filters with peaks between 350-365 nm. It happens that Rudbeckia rays (petals) reflect UV around 350 nm or so. We would therefore expect the BaaderU to show the rays with a brighter tonality than the SEU Gen2. You can see for yourself that this is the case. So cool !!!! And I also had a surprise from the painted background behind the flower. Somewhere between 350 nm and 390 nm that paint begins to become more UV-reflective.

 

 

Unfiltered Reference Photo

f/11 for 1/5" @ ISO-100 = f/11 for 1/40" @ ISO-800

This photo seems to be slightly more Visible than Infrared?

d610_uvNikkor_NoFilter_ambientIndoor_rudbeckia_20180725shoreCottageSwhME_5991rawComp.jpg

 

 

SEU Gen2 Black & White Rudbeckia

f/11 for 15" @ ISO-800.

This exposure gave a centered brightness histogram and a report of no over- or under-exposure from Raw Digger. The exposure is 6.33 stops slower than the Vis + IR exposure.

d610_uvNikkor_uvSeuGen2_ambientIndoor_rudbeckia_20180725shoreCottageSwhME_5998res.jpg

 

 

BaaderU Black & White Rudbeckia

f/11 for 30" @ ISO-800

This exposure gave an almost centered brightness histogram with a report of no over- or under-exposure from Raw Digger. I could have used another 1/3-1/2 stop, maybe, but I did not want to go to bulb or change the ISO setting. I made up for it in the converter. (Not good practice though.)

d610_uvNikkor_uvBaader_ambientIndoor_rudbeckia_20180725shoreCottageSwhME_6002res.jpg

 

 

SEU Gen2 in Raw Color

This is attractive and could be used without white balancing.

d610_uvNikkor_uvSeuGen2_ambientIndoor_rudbeckia_20180725shoreCottageSwhME_5998rawComp.jpg

 

 

BaaderU in Raw Color

d610_uvNikkor_uvBaader_ambientIndoor_rudbeckia_20180725shoreCottageSwhME_6002rawComp.jpg

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Andy Perrin
SEU Gen2 in Raw Color is super. For all the talk about the technical details, it is really "can you make nice photos with it" that matters.
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That is for sure the bottom line! And the SEU Gen2 does make nice photos.

 

I also really like those SEU G2 raw colors. They feel like UV to me. ;)

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Awesome work Andrea! Really like the detailed contrast in the b&w BaaderU shot, but the SEU G2 Raw color is a beauty!
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Thanks, Gary.

 

I think I am going to mention the SEU Gen2 raw color in the filter test summary which I'm working on now.

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Awesome work Andrea! Really like the detailed contrast in the b&w BaaderU shot, but the SEU G2 Raw color is a beauty!

I agree!!

It would be interesting to see similar SEU2 raw images, but with from a sunlit flower.

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Thanks, Ulf!

I will put up a sunny Rudbeckia when the weather clears. It's been a mess here for days. :(

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We are 18 feet from the waters of Somes Sound. Lots of reflection. :D

But those UV exposures were extraordinarily looooooooong at 15" and 30".

And I had to go all the way up to ISO-800.

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It would be interesting to see similar SEU2 raw images, but with from a sunlit flower.

 

Here is the same flower photographed in strong sunlight. And a bit of wind was coming off the water also. I'm thinking these all might have been a touch sharper if I had a way to pin down the Rudbeckia. :lol: I shouldn't be making excuses, but I don't want anyone to think that either of these filters lacks sharpness.

 

The raw composites from Raw Digger were brightened and locally sharpened in NX2.

The white balanced versions were converted in Photo Ninja and locally sharpened in NX2.

 

The raw colors of the UV-reflecting flower petal tips seem to contain slightly more orange than they do in the indoor photos posted above. The background has changed. In these photos the background is a gray wooden deck. The UV-dark flower centers are a bit brighter here as a natural result of the sunlight shining directly on them.

 

I added the white balanced conversions so you could see that the SEU Gen2 can produce a false yellow. The SEU Gen2 UV-dark bull's-eye has more of a green cast than the BaaderU bull's-eye.

 

 

610_6125_NEF.jpg

 

 

610_6125pn.jpg

 

 

 

610_6118_NEF.jpg

 

 

610_6118pn.jpg

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I'm eager to see how an SEU Gen2 raw composite looks from a Pentax or Sony or other camera. I'm sure it will be basically the same, but still I'm curious.

 

I remember some time back, Iliah at Raw Digger mentioned the possibility of putting a better demosaicing algo into Raw Digger. If they do ever do that, then I would use RD for all SEU Gen2 conversions to ensure those nice raw colors. I should try with Dark Table and see what I get.

 

So many experiments to do -- and not enough time.

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