[Filter Test] (Teaser) Sunflower in UV with New Filter (NOW REVEALED!)

[Andrea B.]

[Edited: 25 Aug 2016 to add filter names and info about the new filter.]

 

I'm testing new filters, so I used this happy sunflower as a test subject.

All info about Filter S below will eventually be revealed. :D

 

REVEAL: Filter S = UVR Optics StraightEdgeU UV-Pass Filter

I accepted a test copy of the new StraightEdgeU in order to run various tests. It is named that because the right-hand transmission slope is very steep, almost-but-not-quite vertical.

There will be an online review soon.

 

I'm very pleased with both the UV-photos shown below.

Both UV files were given similar conversion and edits.

But it's early days yet for determining the 'best' look for the new filter.

 

I can say that the new UV-Pass Filter looks like a winner!

 

Gear: Nikon D600-broadband + Coastal Optics 60/4.0

 

Converter: Photo Ninja 1.3.4b

Capture NX2 was used for some minor edits after conversion.

Photo Mechanic was used for crops and resizing.

 

The following photos all click up to 1200 pixels wide in an expanded browser.

 

Visible Reference: f/11 for 1/200" @ ISO-100 with Baader UV/IR-Cut Filter

 

UV-Pass Filter S = StraightEdgeU: f/11 for 6" @ ISO-100

 

UV-Pass Filter M = BaaderU: f/11 for 5" @ ISO-100

[Andrea B.]

[Edited: 25 Aug 2016 to add filter names.]

 

I had a few breezes blow in from Norway when shooting these little Blackfoot Daisies, a Melampodium cultivar named 'Showstar'.

 

Gear: Nikon D600-broadband + Coastal Optics 60/4.0

 

Converter: Photo Ninja 1.3.4b

Photo Mechanic was used for crops and resizing.

Both files were given identical conversion and edits in Photo NInja.

White balance was made on the garden dirt in the lower left corner.

 

The following photos all click up to 1200 pixels wide in an expanded browser.

 

Visible Reference: f/11 for 1/50" @ ISO-100 with Baader UV/IR-Cut Filter

 

 

UV-Pass Filter S = StraightEdgeU: f/11 for 4" @ ISO-100

 

UV-Pass Filter M = BaaderU: f/11 for 5" @ ISO-100

[Andrea B.]

[Edited: 25 Aug 2016 to add filter names.]

 

Here are the Sunflower raw composites from Raw Digger.

 

The files have been demosaiced, autoscaled and gamma-ed. No white balance has been applied. These are the raw colours as seen after stuffing the files into an sRGB JPG box.

 

Visible Raw Composite

 

Filter S = StraightEdgeU Raw Composite

 

Filter M = BaaderU Raw Composite

[Andrea B.]

[Edited: 25 Aug 2016 to add filter name.]

 

Alternate false-colour interpretation for Filter S = StraightEdgeU.

[DaveO]

Those sunflowers are cleverer than you think according to this

Sunflower tracking

http://science.sciencemag.org/content/353/6299/587

 

Dave

[Andrea B.]

:D

They are indeed clever, Dave. I quite love the things.

One of my photographic goals is go somewhere and shoot a whole field of them next summer!

 

The sunflower shown here is a cultivar of some kind which only grows about a foot tall. Very cute. I'm going to put the pot out in stronger sunlight today and look for the heliotropism.

[Guest]

That looks great. I almost opted for the StraightEdgeU, but chose the Andrea U Mk II instead because the Asahi ZRR0340 I already have seems to do a great job of yielding uncontaminated UV images for me. I figured the AndreaU, even with its slight bleed over 400nm, would be a good 'casual' shooting UV filter.

 

Its good to see that you don't seem to have any gradient effects from StraightEdgeU, being that it is a dichroic filter. And the detail is beautiful in your images.

[rfcurry (1950-2024)]

Mark,

 

Try out the NIR blocking of the AndreaU MK II. It is nearly as strong as the StraightEdgeU, it might help with your night shots.

 

Cheers,

Reed

[JCDowdy]

Reed,

 

How does this new filter differ from the PrecisionU and has the PrecisionU been discontinued?

[rfcurry (1950-2024)]

John,

 

The PrecisionU has been discontinued, in favor of the StraightEdgeU. The original Andrea 'U' is also no longer made.

The StraightEdgeU is my response to the perceived need for optimum capture of the longer UVA wavelengths, 360-395nm and superb NIR blocking. I had a firm make a thin dichroic filter that would meet certain very stringent specs, e.g., 94% T at 379nm with a sharp drop to 0.2% at 395nm, and >OD4 from 405nm - 800nm. They exceeded those specs! To this I cemented an ionic glass which is much better in the UV than even the Schott glasses, having minimal effect on the dichroic UV numbers. This melt also is very effective in driving down the 700nm+ numbers. But sufficient thickness of glass is necessary.

 

The StraightEdgeU was an expensive gamble (for my meager wallet). But, IMO, it has paid off.

[Andrea B.]

I have some raw composites all with similar saturation and brightness which help illustrate the predominate recording channels in some of these filters.

See this LINK: http://www.ultravioletphotography.com/content/index.php/topic/1949-filter-test-raw-colour-differences-in-6-uv-pass-filters/