Attempt to auto white balance in-camera (Nikon) with blue or green filters

[lukaszgryglicki]

Hi, I just wonder if it is possible to achive auto white balance in-camera (Nikons are known to cowardly refuse to set white balance from IR/UV/FS photos).

 

I want to be able to do multispectral photo with just one filter - ideally that would include visible & IR + as a bonus, possibly, just a bit of UV.

Images without filters are "too red" for Nikons to auto WB, so my idea was to add a filter that will block most red around 650-750 nm to make it able o do auto WB.

 

Hoya blue & green filters seems to be good candidates:

- Hoya C4, C8, and especially C12 hav a very suitable transmissions IMHO: https://hoyafilter.com/product/c8_blue_cooling/ (C12 seems to be cutting visible quite a lot but it passes UV which is good, C8 looks best at the first glance, but it may just start cutting red on too long wavelengths, C4 seems least interesting and also cuts UV).

- Hoya X0, X1: https://hoyafilter.com/product/x1_green/ (both cut UV :-( but X0 passes a lot of IR and may be just enought to auto WB).

 

The question here is: does anybody used any of those (or Nikon X0, X1 filters) on a Nikon full spectrum body and was able to auto white balance?

 

I always prefer to shoot many photos in JPEG than doing RAWs and then converting them - auto white balance in-camera woudl help a lot with spot-checking if my settings are OK, also could have some fun artictic colors - I always prefer to shoot handheld and close as much as possible to a normal mode. If such X0 or C8 would make it possible, I would order them and use for my full spectrum shots (ideally I just want to keep as much as possible IR and UV and surpss just enough red channel to be able to AWB).

 

[Andy Perrin]

I have no way to check but I really doubt a filter would let it white balance? This is because the software must have numerical limits built in for what the lowest/highest color temperatures it will allow are, so changing what light goes into the camera should not be able to alter the software issue. But perhaps I will be surprised. 

[lukaszgryglicki]

We will see, I've found X0, X1, 80A and 80B cheap locally (in Poland) so I've ordered them. My impression was that even without filters D600 is "almost" able to AWB - what is funny is that D3200 manages to AWB so I think we're "close" - maybe, especially 80A/80B will make it work OOTB.

[lukaszgryglicki]

One of Hoyas arrived Hoya 80B 52mm. Full spectrum converted nikon D600 *is* able to auto white balance with it :-D huuuuuraaaaay!!

Viewing through the viewfinder is a bit blue, sure, but it *works*. I can shoot my favorite way - through the lens. In a 50% cloudy/sunny daya I just need to dial -1.3 stop exposure compensation and photos are OK. I can also white-balance to a white wall of a building - use this as a wb source photo in-camera and that works too.

 

Those are JPEGs straight from camera (just scale down to 1/5 size for the forum - the first one is just a WB reference photo):

 

 

[dabateman]

But does it white balance in UV now? With you UV filter stack on your lens? 

That seems to be the main Nikon problem is the limited internal Kelvin range on the white balance. 

 

[lukaszgryglicki]

This is not at all related to UV - this won't help in UV at all.

This only means that a converted D600 is able to auto white balance with that filter alone.

Without filter, if I make a photo of "white" wall and use it as a WB source - it looks like it is ignore and colors are pink/red.

Wit that filter I do the same white wall photo, use it as a WB source and it works - the wall is white when I shoot anaother photo white balanced to the previous one. This is EXACTLY what I wanted to achive with that filter.

 

 

[dabateman]

Try it it might allow enough UV through if its a Hoya filter.

The Chinese SSB might be different. 

 

[dabateman]

Ok,

Maybe I am not thinking clearly or explaining it.

Try in a dark room without sunlight and a strong UV mostly light source with the 80B filter only to see if you get better UV white balance settings. 

In hindsight this might not work at all. Just for full spectrum as you wanted.

The problem is Nikon cuts off below 10000 Kelvin and above 2500 Kelvin, so making the WB in IR and UV is really hard.

My bad thought was if you push a little more blue through, than it might lock on.

So set a white balance setting with 80b in mostly Uv light, like a Blb compact fluorescent bulb. 

Then switch to your uv filter stack and see if its reasonable. 

Again most likely wouldn't work. Would be like trying WB with just a BG39  filter.

[lukaszgryglicki]

So I did that and I cannot WB:

- UV flashlight.

- IR flashlight.

- Both at the same time.

 

This is all with Hoya 80B on Nikkor 35/2 lens.

 

The funny thing is (the last photo with both) that UV flashlight is easy visible as violet and quite intensive, IR is invisible at all on the wall, and when I look directly into its IR diode I can only see a faint red glow. But on the fs photos the IR one is a lot more bright...

 

[dabateman]

Ok makes sense. Definitely not the first time I have been wrong. 

Was just kind of hoping it would work. 

My Olympus cameras are excellent at white balance since there manual Kelvin range is 2000 to 14000. I have been looking for an other camera with that range, but all other manufacturers fall short. 

Even with 14000 its a little tricky to get WB in UVB, as its a little over 15000.

[Cadmium]

Actually, any BG filter will transmit UV and Visual range, and some will transmit some IR as well.
However, white balance can not remove a range of light, such as remove UV from a UV/Visual range filter.
The lens is a filter, and with no other filtration you can not remove any range of light entering the camera.
White balance only balances the overall color of the entire range. You can not just use white balance to restrict your filtration to selected ranges.

You need to use different filters to define the range. Then white balance from that.

 

Furthermore, white balancing UV or IR in a Nikon is pretty much impossible.

Try as you might... that is not going to get you a good white balance, mostly you will just get the message, "No Good".
Nikons just seem to have no clue about out of visual range filtration.
It is best to white balance from RAW in some program like Photo Ninja.
It would be nice if we could do that to a file, then put it back in the camera to use as a preset white balance reference,

but that is not allowed, and I never found a way to do that.

 

You need different filters, and you need to white balance from NEF files on the computer.

 

 

[Andy Perrin]

If you want full spectrum photos white balanced in camera across the whole range, I don’t think anything will work on those Nikons. As you saw, visible only seems to be ok, but not outside that. 

[lukaszgryglicki]

I understand all of this, I know that I need filters for filtration etc.

All I wanted from those Hoyas was to be able to get photos that look good to me out of the camera without RAW processing.

I already have my own scripts to white balance to a NEF file, so white balancing RAWs is not a problem at all - can do it for fs, IR, UV, visible whatever.

This is only about allowing auto white balance in camera, so photos look good just after shooting when I hit preview button.

This may be strange but it is actually important for me to have such an option.

Another one is to use IR/UV cut filters that I have - they kinda convert fs camera back to visible and they always worked OK (colors are a bit different that unconverted camera but that's OK too), here I have something kinda similar, but for full spectrum - Hoya 80A/80B only subtracts this crazy amound of light registered in the red channel while still passing UV, visible, IR - exactly what I want.

 

[Andy Perrin]

Why don't you get BG38 2mm? That filter (as tested extensively by Andrea) has proven to be the best to restore Nikons to near-factory colors, particularly after correction with a color checker, but even without that.

[lukaszgryglicki]

I don't want to restore conlors - I already have filter that can do it. I want to have full spectrum - but recorded more evenly across R G B channels, and those blue filters allows me to do this.

 

[Andy Perrin]

Ok, as long as you are happy!