Panasonic Lumix DMC G3 Camera

[Andrea B.]

Yes, that's certainly true that it is good to refresh the WB in each shooting scenario. :D

With the Nikons a preset WB can only be a place to start when shooting UV because they cannot go the full distance to a "true UV false colour white balance" in-camera, but only in-editor.

 

Gotta love the concept of true false colour - as I have observed and laughed about before.

[JCDowdy]

Sunlight is constantly changing and the UV composition varies with solar angle.

 

So, if one is shooting UV outside, frequently refreshing a custom WB might not be a bad idea.

[Andrea B.]

I'm not sure I've ever seen all that much change while shooting outside. We are only catching a limited UV range even with our wideband filters.

 

However, this would make for an interesting experiment for folks to try. Go out and shoot the same scene every hour on the hour during the day. Subject them all to the same editing and see what you get??

 

OK, I've just confired I am a dyed-in-the-wool UV-nerd with that suggestion. ;) :D B) :P :P

[kds315]

I have my UV "white" balance disc in my pocket when I'm out shooting under varying conditions, but actually the differences are neglectable mostly.

 

I use(d) GH1 and now GH2, gives 4 WB settings which I use for different filters, plus a Kelvin temperature setting for studio use (VIS).

 

I had a converted G3 (for a project) but cannot remember in detail how it was different. I set UV-WB and all worked nice and easy.

[colinbm]

I am looking at setting a Custon WB on the G3, I am wondering what the equivalent Kelvin value is please ?

For those that set their UV, CWB from a Teflon block, I am wondering if they are able to read the K value too ?

Col

[nfoto]

PhotoNinja says 2000 K. probably a limit of the software, though.

[colinbm]

Thanks Bjorn

That is close to candle light, <2000K.

I am trying to capture a CWB, with the converted G3 & the Baader U2 on the lens.

I want to save a daylight UV at CWB1 & a MTE 365nm UV to CWB2, both using a Teflon block.

They are both looking very much the same, is that what you have found ?

There may be subtle differences, when I do some shots & process them ?

Cheers

Col

[Andrea B.]

With the BaadU both setups are peaking around 365nm (of course), so it isn't surprising your WB is about the same for both.

 

In practice, you might find that the MTE fotos are more monochrome or have somewhat less intense false colour than the daylight fotos.

It depends on the subject and how close you are to it. So yes the differences may be subtle. Or they might be obvious.

 

Make a landscape foto with both WB settings. Then oversaturate the fotos in the converter/editor to see where the false colours are.

Repeat this with a close-up.

 

*****

 

While it is nice to shoot UV with an in-camera WB setting, you should always fotograph the Teflon at the beginning of each session in the same light that the subject will receive. Then you can make adjustments in the editor to the recorded WB. I've found that in-camera WB settings made indoors are different than outdoors. No surprise there. I've not found all that much difference in WB for UV based on times of day, but differences do appear depending on the amount of shading. Again no surprise about that. "-)

 

Actually, what we should do at the beginning of each session is re-set the in-camera WB. I'm lazy and just readjust WB in the converter from a foto of the white standard.

 

*****

 

Post some results as you go along Col. Let us see how it is all working out !!

[kds315]

The MTE UV LED hardly produces any "colors", as it it basically a monochrome light source around 365nm, so leads to a quite yellow image in a image, when shooting preset white balanced using sunlight and Baader-U filter.

[colinbm]

Thanks Klaus

Yes that is what I am finding.

Col

[colinbm]

Thanks Andrea

Does PhotoNinja do any auto processing when it opens a G3 RAW2 file ?

Looking at the photos in PN after they have opened, don't seem to need any processing or perhaps I'm not discerning yet ?

The UV Custom White Balance, is already at the bottom limit of adjustment, 2000K in PN, so how do you do any more correcting ?

Still lots to learn, & getting a good infinity focus. I haven't got any 3 or 4mm quartz yet. Just trying to get it with the heliciod.

Col

[Andrea B.]

Photo Ninja has a Defaults button under Adjustments to the right.

There you make some settings for your initial view of the foto.

My settings are (in order):

 

Neutral

As shot

As shot

Low

Off

*****

Neutral

Neutral

Neutral

Off

*****

Noise Ninja 4

 

Now, first, on the main page, if Photo Ninja recognizes your camera (which it should) you will see the camera name beside the Profile button.

The Lens & Focus buttons will probably not be set unless you are using a kit lens. Or they will read 'unknown'

 

Second on the main page are the various buttons for edits. When you open a previously unedited foto, I think you see the following buttons checked with certain default settings (in parentheses) which are taken either from your Defaults or from the Camera settings.

 

Demosaic (Conservative :: Balance G0/G1 checked)

 

Color correction (Light Source = daylight/flash :: Mode = from Camera with temp/tint from Camera :: Strength 50)

This is Photo Ninja's attempt to read and match your white balance setting.

 

Exposure and Detail (As Shot :: As Shot :: then all settings 0 except for Highlight correction)

This is Photo Ninja's attempt to read and match your exposure and apply your camera's gamma curve.

 

So the default starting place is for Photo Ninja to try to interpret your camera settings as best it can and start from there. It also immediately corrects highlights.

 

If you don't want to see anything but the raw, uncheck everything but Demosaic.

 

I can't remember if PN starts with sharpening or noise settings. I can't find an unedited foto to test that out!! :)

[Andrea B.]

Col: The UV Custom White Balance, is already at the bottom limit of adjustment, 2000K in PN, so how do you do any more correcting ?

 

If you are applying a custom white balance you have made and saved within Photo Ninja as a Preset or as a Custom Light under Light Source then you are done. No further correction needed.

[colinbm]

Thanks Andrea

All understood, surprisingly for me, you must be a good teacher.

Here is an early works from me.

Col

 

I was concentrating on getting the top of the power pole, behind the roof ridge, in focus, I had to use f5.6 for that & still got good DOF overall.

Panasonic G3 converted with no added internal glass, but with a helicoid to get infinity focus, which was approx -2mm off FFD.

Mayfair Cryatar 35mm f3.5 lens, set at f5.6, camera set at ISO 200, 0.4 sec, & Custom WB off the Teflon block.

[colinbm]

Hi Andrea

You have grey & black Teflon pucks in your Colour Checker box.

I am having trouble getting a CWB of the white Teflon, the G3 keeps telling me it is too bright.

I wonder if the grey or black Teflon would solve that problem please ?

Col

[kds315]

Hi Andrea

You have grey & black Teflon pucks in your Colour Checker box.

I am having trouble getting a CWB of the white Teflon, the G3 keeps telling me it is too bright.

I wonder if the grey or black Teflon would solve that problem please ?

Col

 

Can't you just stop down the lens to solve that, or reduce ISO speed? Always works for me... Btw it is better to defocus while doing this.

 

I would not use greay or black Teflon for that - actually Andrea is using SPECTRALON ® Targets, very expensive those are, even used.

[colinbm]

Thanks Klaus

More testing tomorrow.

Col

[Andrea B.]

Col, to avoid the brightness warning, first set ISO to the base level on the G3 and then stop down to somewhere between f8-f16 in aperture mode. That should enable you to record a good in-camera wb without the warning. While you do want your white target illuminated by the same light as the subject, it is ok to turn the target slightly so that it does not reflect so strongly back onto the sensor.

 

I'm thinking I remember that backing up a bit off the white target can help as long as you keep the focus point on the center of the target. The target need not fully occupy the viewfinder to make a good in-camera wb. As Klaus mentioned, defocusing a bit can be useful.

 

Your sample shot posted above looks good. A bit of chromatic aberration, but that is fixable.

[colinbm]

Thank Andrea & Klaus

I have got the CWB to take, with the above advice, f16 & infinity focus.

I have taken this shot & others & I like the blues to grey to black, a bit noisy at ISO 1600, but PhotoNinja took care of that.

Col

 

Panasonic G3 converted with no added internal glass, but with a helicoid to get infinity focus, which was approx -2mm off FFD.

Mayfair Cryatar 35mm f3.5 lens, with BaaderU2 filter added, set at f5.6, camera set at ISO 1600, in Aperture Priority, 0.4 sec, & Custom WB off the Teflon block.

[JCDowdy]

I have got the CWB to take, with the above advice, f16 & infinity focus.

 

Looking good Col, you are picking up on this UV CWB quickly!

 

I have occasionally experienced the SCENE IS TOO BRIGHT error in setting CWB, especially with strong flash, even at base ISO and minimum aperture size. I noticed you mentioned you set CWB at INF. That is the smallest image circle a lens can produce, putting the most energy on sensor. I have found that defocusing in the opposite direction to closest focus, which produces largest image circle, sometimes helps reduce energy on sensor enough to avoid this CWB issue.

[colinbm]

Thanks John, I will try that too.

Col

[colinbm]

Steven Smeed's Sparticle Filter Array test.

Isn't it pretty :)

Col

 

Panasonic G3 camera, set at ISO 200 & taken at 0.25secs, & a Steven Smeed Sparticle Filter Array, with four UV, narrow band pass filters, 340nm, 350nm, 370nm & 386nm, placed in front of the lens, with the BaaderU2 to block the IR.

Taken of clear blue sky, some power cables too.

Preset CWB with a BaaderU2 on a Teflon block in Sunlight.

Mayfair Crystar 35mm f3.5 lens at f4 & infinity.

[Alex H]

Colin, that looks good.

Alex

[colinbm]

Thanks Alex

Yes I am pretty happy too.

The 340nm exposed OK without much effort, only just a small amount below the others.

Col

[kds315]

Thanks Alex

Yes I am pretty happy too.

The 340nm exposed OK without much effort, only just a small amount below the others.

Col

 

Looking good! That was done in onbe shot or four different ones? I guess the former.

The 360nm usually looks a little less green, but that might be the processing applied.