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UltravioletPhotography

Colorchecker Passport in Solar UV


rfcurry

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I haven't found any shots taken in solar UV of the X-rite Colorchecker. I believe it might be interesting to see how different lenses provide varying interpretations of the CC.

 

Here are a few --

 

All photos below are in solar UV, taken on a cloudless day through a double-paned window, with a Panasonic GF1, ISO 400, f8.0, and CopperU. All lenses were WB in-camera. The images were then one-click WB and cropped. Sorry about the mullion shadows, but I couldn't get the sun to stand still. :angry:

 

The three lenses are all four element. The Tessars are 4 elements in 3 groups, the Primagon is 4 elements in 4 groups. All are Exakta mount.

 

Carl Zeiss Jena Tessar 50/3.5 (made between 1952-1955)

 

post-19-0-99258300-1425751014.jpg

 

Carl Zeiss Jena Tessar 50/2.8 (made between 1967-1970)

 

post-19-0-48971300-1425751025.jpg

 

Meyer-Optik Gorlitz Primagon 35/4.5 (made between 1955-1957)

 

post-19-0-99396400-1425751019.jpg

 

The Tessar 50/3.5 is the oldest of the three lenses but provides the brightest colors. The Primagon is no slouch, though.

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Double glazing severely limits the UV intensity and spectral range penetrating the glass. I doubt there is much below 370 nm to be recorded.

 

Over here we use triple glazing so shooting any meaningful UV indoors with sun light streaming through the window pane is well nigh hopeless.

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Another lens.

The photo below was taken in solar UV, on a cloudless day through a double-paned window, with a Panasonic GF1, ISO 400, f8.0, and CopperU. All lenses were WB in-camera. The images were then one-click WB and cropped.

 

The Jsogon (Isogon) has 4 elements in 4 groups. The lens is an Exakta mount.

 

Schneider Kreuznach Jsogon 40 mm f/ 4.5 (made in late 1952)

 

post-19-0-74261000-1425754941.jpg

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Bjørn,

 

Yes, I know about the limitations, but it is too cold to go out. :angry: Three feet of snow also hinders my efforts.

 

I believed that since all the lenses were encountering the same sensor limitation, the CC would highlight the lenses' capability.

 

However, I guess it was a waste of time. I don't have the rights to delete this thread. Please delete it for me. Thanks.

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Well, no, let's leave the thread. It is not totally without merit. OK, sure, Reed shot thru double-paned windows. But some "near UV" was recorded. And also the thread serves as a prompt for me to drag out a few shots of the CC Passport made in solar UV outdoors. Not particularly good ones, but still useable for illustrative purposes since Reed mentioned never having seen any posted.

 

I am not sure why the CopperU gives so much false yellow? It is interesting, though.

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All shots were made outdoors in full sunlight using the Baader-U and Pentax K5 broadband.

The amount of sunlight may have varied during the shoot.

 

These shots are deliberately soft-focused for use in building Photo Ninja profiles and for white balancing on the standards. Shooting too sharp can perhaps confuse the profiler as per Photo Ninja directions. And white balance samplers vary in size so you don't want to pick up an area on the standards which is not representative.

 

The photos will appear somewhat dark because I could not let the 99% white standard blow out or the resulting photo would be useless for white balancing on that standard. Typically we would shoot our UV photos a little brighter and perhaps 'rescue' blow-outs in the converter. There is probably some pronouncement which could be made about just how dark UV shots really are. If we left them that way, we would have lousy photographs. :angry:

 

As you can see from these examples, after profiling the shots look pretty much the same except perhaps for the Meritar shot which was made with a light-leaky adapter (not the len's fault at all !!).

 

I used a generic in-camera UV white balance to make all the shots. I'm pretty sure it was made with the UAT 85/4.5 which lives on the K5-broadband. However the Tessar shot looks good too before any profiling.

 

All shots made at maximum aperture for that lens.

 

Asahi Optical Co. 135/3.5 Takumar

Original shot using a generic in-camera UV white balance.

1/1.3" @ ISO-400

k5_asahi135_std_uvBaadSun_092014mt_114645.jpg

 

Photo Ninja conversion using white balance on standards and Tak 135/3.5 Custom Light profile made from visible shot of CC Passport.

k5_asahi135_std_uvBaadSun_092014mt_114645pnProfile.jpg

 

Just for the record, here are two other possible choices for profiling in PN.

I'm only going to be tedious with showing these just this once for the 135/3.5 Tak and will skip it for the rest of the lenses.

 

Photo Ninja conversion using white balance on standards and Photo Ninja's Daylight/Flash for the built-in K5 profile.

k5_asahi135_std_uvBaadSun_092014mt_114645pnDaylight.jpg

 

Photo Ninja conversion using white balance on standards and No Profile. All wrong!

k5_asahi135_std_uvBaadSun_092014mt_114645pn3NoProfile.jpg

 

 

E. Ludwig 35/3.5 Meritar

The lens did not entirely cover the Pentax M42 to Kmount adapter so there was a light leak. At the time I did not realize where it was coming from.

 

Original shot using a generic in-camera UV white balance. The cyan light leak from the adapter is at bottom left.

1/2.5" @ ISO-400 with EV=-.7 => 1/4"

k5_meritar50_std_uvBaadSun_092014mt_121130.jpg

 

Photo Ninja conversion using white balance on standards and Meritar 35/3.5 Custom Light profile made from visible shot of CC Passport. I will need to remake this profile now that I know the source of the light leak - although I'm not sure how much that might have affected the Visible shots.

k5_meritar50_std_uvBaadSun_092014mt_121130pnProfile.jpg

 

 

Carl Zeiss Jena 50/3.5 Tessar

Original shot using a generic in-camera UV white balance.

1/25" @ ISO-400 with EV=-2.0 =>1/100"

k5_tessar50_std_uvBaadSun_092014mt_120428pn.jpg

 

Photo Ninja conversion using white balance on standards and Zeiss 50/3.5 Custom Light profile made from visible shot of CC Passport.

k5_tessar50_std_uvBaadSun_092014mt_120428pnProfile.jpg

 

 

Novoflex 35.3.5 Noflexar

Original shot using a generic in-camera UV white balance.

1/6" @ ISO-400 with EV=-2.0 => 1/25"

k5_novoflex35_std_uvBaadSun_092014mt_123638.jpg

 

Photo Ninja conversion using white balance on standards and Novo 35/3.5 Custom Light profile made from visible shot of CC Passport.

k5_novoflex35_std_uvBaadSun_092014mt_123638pn.jpg

 

 

Asahi Optical Co. 85/4.5 Ultra-Achromatic-Takumar

Original shot using a generic in-camera UV white balance.

1/10" @ ISO-400 with EV=-1.3 => 1/25"

This photo seems to confirm my statement above that this in-camera wb was made with this UAT because the standards are neutral.

With unprofiled K5 colour, however, the patches are more violet-blue than blue.

k5_uat85_std_uvBaadSun_092014mt_124619.jpg

 

Photo Ninja conversion using white balance on standards and UAT 85/4.5 Custom Light profile made from visible shot of CC Passport.

k5_uat85_std_uvBaadSun_092014mt_124619pn.jpg

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So, Reed, set everything up for the shot. Run over and open the window. Shoot. Go close the window.

 

I would enjoy seeing more from your Copper-U prototype.

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Andrea,

 

After the window admonition yesterday,I stumbled outside for a quick shot. The lens is a CZJ Tessar 50/3.5 made between 1952-1955. Panasonic GF1, ISO 400, f8.0, 5.0s, solar only, very overcast, and CopperU.

 

#1 The image below has only an in-camera WB and reduction to 1500px width.

post-19-0-50136400-1425855695.jpg

 

#2 This image is the same as #1 after a PP one-click WB, cropping to the CC, and 1500px reduction.

post-19-0-49543000-1425856229.jpg

 

#3 This is the indoor image in the first post, cropped to the CC and reduced to 1500px

post-19-0-95890700-1425855683.jpg

 

The difference between the indoor and outdoor shots is not very great. The outdoor has more blue and higher color intensity.

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John,

I don't understand why your CC is so dowdy! :angry:

 

Seriously, is it just the in-camera WB I do? Below are two images taken with a Meyer-Optiks Primagon 35/3.5, made in 1955. Photos below were taken in solar UV on a cloudless day through a double-paned window, with a Panasonic GF1, ISO 400, f8.0. Then one-click WB and reduced to 1500px width.

 

First with a CopperU at 1.3s

post-19-0-69803000-1425873714.jpg

 

 

Then with a PrecisionU at 1.6s

post-19-0-74727900-1425873718.jpg

 

The peak of the CopperU and the breadth of its FWHM are greater than the PrecisionU. This may be reflected in the shorter exposure but more intense colors.

 

Ideas?

 

Regards,

Reed

 

P.S. - the transmission curve may be found at http://uvroptics.com/index.php?CopperU . It may require updating based upon recent changes.

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I don't understand why your CC is so dowdy! ;)

P.S. - the transmission curve may be found at http://uvroptics.com/index.php?CopperU . It may require updating based upon recent changes.

 

Ha-Ha, you so funny, you up my crack! :angry:

Oh, and thanks for the link!

 

Interesting you are getting this unique UV false color pallet with your PrecisionU also.

I have the AndreaU as well as the BaaderU and for that matter DUG-11 and while each do produce slightly different UV false colors with in camera WB I have never gotten anything close to what you are showing here with any lens or WB option. Do you see this also with a BaaderU?

 

You must be doing something very different in your in camera WB or PP or else your camera is responding differently than anyone else's I have seen. That is not necessarily a bad thing, whatever it is you have somehow expanded the false color range dramatically it seems.

 

Sometime when you can, please detail your WB and PP process with which you produce this. I would like to attempt to replicate your result.

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Hi Reed

The link to the CopperU is impressive, to say the least. I look forwards to being able to purchase one soon.

Cheers

Col

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John,

 

It has nothing to do with PP, as you can see from the image shot on the bricks in a previous post above. That had no PP.

I shoot jpgs, not RAW. Ninety-nine percent of the time I use Standard "Film Mode", e.g., not Dynamic, Smooth, etc. I perform an in-camera WB whenever I begin a shot that requires a lens, filter, or lighting change. I center a 73mm PTFE disk in the viewing aperture of the GF1 "set custom WB" frame while focused on the intended image area and with the final exposure rate already set. Then I just click the button to set the WB and remove the PTFE. Simple.

 

I don't have a Baader U, I gave mine away.

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Without a raw I don't think we can figure out what is going on with your colour balance Reed. I do not see anything in your description which I wouldn't do!! I only have the "old" PrecisionU so I don't know if its slightly different trans curve would produce anything different from what you've shown, but I will try a test with my GH1.

 

But whatever -- it is nice to see the progress of the CopperU which will be a good addition to UvrOptics. :angry:

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well Reed....that doesn't quite work. :angry: ;) :lol: Here's what I saw for the first RW2.

 

Screen Shot 2015-03-09 at 11.28.05 AM.jpg

 

DROPBOX: https://www.dropbox.com/

If you have a Dropbox account, then upload the raws there and give us the download link.

If you don't have a Dropbox account, then you might like to have one? It is free for light use and quite useful.

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I'm getting the same thing. So it is either the lens or the filter?? More experiments needed. :angry: I'll go dig out my GH1.

 

In Photo Ninja, for both these I chose the BuiltIn DMC-GF1 Profile, the Daylight/Flash light source and performed manual white balance on black patch. Photo Ninja's built-in colour profiles are pretty darned good approximations for Daylight if you don't want to go to the bother of making your own Daylight profiles.

I also chose in Photo Ninja Plain colour @ intensity=50 in the Color Enhancement tool.

 

SET 1

 

In-camera jpg P1110879

P1110879.jpg

 

Photo Ninja conversion P1110879

P1110879pn.jpg

 

*****

 

SET 2

 

In-camera jpg P1110878

P1110878.jpg

 

Photo Ninja conversion P1110878: a little more saturated than the in-camera foto.

The in-camera wb shows a bit of blue in the lettering which does not appear on the PN version.

But then I was using the black patch for manual wb, not the best choice. (Not the worst either!)

P1110878pn.jpg

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Those were taken in solar, through the window. No flash, just solar.

I get similar results using any of my pre-1965 lenses.

Could it be my GF1 full-spectrum conversion? IIRC, they removed both ICF and shaker and installed quartz.

 

Thanks.

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I do not find a "Film Mode" under the DMC-G3's Photo Style menu but I do have a "Standard" which is what I use.

My conversion removed ICF and shaker and was left bare, can't imagine quartz window alters to this extent.

You like Steinhill lenses, do you have the 50mm f/2.8 Cassar-S? I have an AndreaU so if you have that lens we can compare similar lens & filter.

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I just ran my Primagon 35/4.5 on my GH1.

 

What I'm seeing is that when I set a GH1 in-camera white balance through the BaaderU filter against a white standard and then shoot the CC card, I do NOT get the standardized blue colours in the shot. Very oddly, however, I do see the standard blues in Live View.

So I'm a bit stumped as to why the GH1 is showing me the white balance thru Live View that I would expect, but the photo is not. [Preceding sentence edited to correct error.]

 

That result does not however negate the RW2 white-balanced photos shown above which were wb-ed in Photo Ninja. Those yellows are there and must be from the filter choice?

 

OK, gotta look at this some more. But I'm a bit out of time as I need to do some other things this afternoon. Back later.

 

*****

 

On top of my GH1 is a Film Mode button. When pressed it brings up the choices for the colour controls under the heading Film Mode. This might have been changed on newer Lumix G models.

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Reed,

 

I just remembered something. When I had the DMC-G3 converted I asked if the dust shaker could be replaced with a UV transparent window such as fused silica or Spectrosil®. I was told that they did not have a way (at the time) to remove the shaker glass from it's gasket-like mount or a way to attach a UV transparent replacement. The shaker window has of course a UV/IR cut dichroic interference coating.

 

You said earlier that your GH1 had both ICF and shaker removed and and quartz installed. Looking at mine the shaker mount frame is what holds the BG-type ICF in place, some DIY conversion instructions show them actually falling out once the shaker glass is removed. Is a GH1 so different from a G3 that the inner filter is somehow secured otherwise?

 

Obviously your CopperU (111nmHBW/270-381nm) is very different than a BaaderU (60nmHBW/320-380nm). There is no reason to assume such a filter to WB the same with regard to UV-false color palette. The "standard" UV-color palette is in reality a BaaderU UV-color palette. The U-360/S8612 or UG-11/BG38-40 and for the most part AndreaU are similar enough that this false color scheme may apparently be consistently achieved across different cameras. With a filter that is transmitting >50% over ~50nm shorter wavelength band which is twice as wide, this simply may not be the case. If there was an hypothetical ideal UV short pass filter with 100% T <400nm and Zero transmission >400 would the familiar BadderU WB & color pallet be expected?

 

I for one eagerly await one of our UV-masters armed with princely UV-Nikkor or Coastal UV-VIS-IR lenses to explore what this CopperU will reveal! It goes without saying I would be delighted to run a 5 or 6 order of magnitude double monochromator transmittance scan of this filter. I will even offer you a special introductory rate, only cost you one filter! :angry:

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John,

 

I don't have the Cassar S, though I keep my eyes open for one. Since I can get the CC effect with many different lenses, I don't think the actual lens is the origin of the colors. Personally, I am accustomed to the various colors and can't understand why you don't have them as well. :angry: Even if I use a WB such as 2500K, rather than a custom WB, the colors (as Andrea noted) in P1110879, are quite distinct.

 

Also, I get similar colors - though subdued - with my PrecisionU filter. That points to my sensor as the "problem" (not that i see greater distinction between wavelengths as a problem, actually, it is a virtue).

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