Setting White Balance with IR filters

[CatherineA]

For those of you who shoot with infrared filters, what is your preferred method for setting a white balance?

I believe some people use Auto White Balance, some shoot grass or something else green, some shoot something red, and others shoot white or grey. Apparently the choice has an impact on what can be done in post but I'm not sure what that is at this stage. I know I need to experiment with the possibilities but I was wondering whether any photographer had anything that they could tell me about their experience.

Thank you

[xpatUSA]

For those of you who shoot with infrared filters, what is your preferred method for setting a white balance?

Catherine, there is no such thing as a "white balance" for infrared shots. White balance, also know as "reference white" only applies to human-visible RGB colors as shown on the well-known CIE gamut diagram. To say more would probably be confusing and invite a flood of disagreement.

I leave my WB set to daylight for all my IR shots and also my 'full-spectrum' shots.

You can check my reasoning by shooting an IR scene with every WB your camera can offer. All your JPEGs will come out a horrible magenta color with little difference between them.

[CatherineA]

Catherine, there is no such thing as a "white balance" for infrared shots.

Thanks Ted! You've always been very kind about my questions. Seems an embarrassingly dumb question this time but there we go.

[xpatUSA]

Ted said: Catherine, there is no such thing as a "white balance" for infrared shots.

Thanks Ted! You've always been very kind about my questions. Seems an embarrassingly dumb question this time but there we go.

Not dumb at all. The literature abounds with advice about how to "white balance" IR captures. Probably something else is meant ...

[William W]

I suggest that if you're using an IR Filter that you capture and use raw files (i.e. NOT JPEG) and the following comments are predicated on raw capture and the use of that raw file in Post Production.

I think that those who actually do know what they are doing and then advocate setting a specific WB when using an IR Filter (as opposed to leaving the WB on AUTO) are mainly doing so for the ease of Post Production continuity and workflow. I expect this reason is not always apparent and perhaps not often not explained adequately.

I doubt that not setting a specific (i.e. leaving it on “Auto” White Balance) actually limits the outcome possibilities, however probably doing so will make the road to some possibilities longer and/or more tedious.

***

If you set a specific WB (i.e. not Auto WB) before you begin, this will allow (probably) easier post production, especially if you want to have continuity of that output, between scenes or between brackets of one scene.

There is also a view, based upon theory, to set a specific 'warm' WB, (for example "Incandescent" if Degrees K is not available) there will be less likelihood of clipping. I quite like the theory but I have never tested the real life value of it.

There is another view that one should use sunlit green foliage in the scene to set WB – again this technique, I understand is stated to limit the possibility of clipping and sometimes the rationale is simply explained in words such as - "that's the area which will be white in the IR Image". This theory prima facie does seem to lack integrity.

***

Frankly, I see no real world value in any argument apropos setting WB for IR to limit clipping, because, in my mind, if I am out there (typically) setting up a tripod and going through all the 48 hours of preamble to make one IR image, (I am an impatient photographer) I’ll spend an extra 60 seconds and make a Bracket of Exposures.

***

As a general comment, if one were to test the relevance of setting a range of specific White Balances, for that test to be also for the purposes of comparisons and contrasts of the end results possible, I think that we’d need to make the test using raw files and not JPEGs.

***

When choosing a specific WB to set, I expect that there will be nuances concerning the different starting points in so far as how each will affect the ease of Post Production, depending upon what one’s typical Final Image is to be. In this regard trialing a few specific WB presets might be a good idea for you, or maybe not. I didn't make any trials.

What I generally want to achieve and my procedure for doing so, is set out here:

I use Hoya R72 Filters.

None of my cameras are modified.

Generally I strive only for B&W as my final product.

I typically use my Fuji X100s

On occasions when the Fuji's lens is inadequate apropos Field of View, I will use a Canon DSLR or Canon M5 and only with a small number of pre-tested and select lenses.

For ease of knowing my Post Production starting point, I reckon that I might as well ere on the side of theory and I typically select "K = 2500" which is the warmest available on the Fuji X100s. (similarly set K = warmest value on my other cameras).

I always make Exposure Brackets (on Exposure Time).

I always choose as low an ISO as practicable.

I only use the raw file.



WW

Image © AJ Group Pty Ltd Aust 1996~2020 WMW 1965~1996

[William W]

After responding to this question I began attending to other important aspects of life – what to prepare and cook for this evening’s meal.

My first stop was the deep freezer for initial inspiration, whereupon I realized that all this IR stuff was far simpler with film, albeit that arguably film does not allow as wide a creative range of Final Images as Digital.

It’s understandable that the link is not obvious on first glance – but it is, if you too were glancing in my freezer –



WW

[CatherineA]

Hi Bill,

Thank you for explaining how you approach taking IR photos - and for that interesting peak into your freezer!

I expect that you are right and that setting the white balance has to do with continuity and convenience during post. It was a good reminder because I want to make a panoramic IR image and I must remember not to use AWB for the individual shots.

I have read others recommend to do what you do, bracket IR shots. The IR shots that I have taken so far have all required exposures of longer than 30 sec and I can't set my camera to automatically bracket then. So I just check my histogram after I shoot and if nothing is blown out then I guess I've got my image.

There is a pretty stone bridge with five arches not far from Ottawa and tomorrow afternoon I will go there with my ND filters and IR filters. I will convert the result and see which gives the better black and white photo. If I find a composition that I like then I will go back early some morning for a sunrise shot and try the filters then too. I'm interested to see how they all compare.

[Manfred M]

Hi Bill,

Thank you for explaining how you approach taking IR photos - and for that interesting peak into your freezer!

I expect that you are right and that setting the white balance has to do with continuity and convenience during post. It was a good reminder because I want to make a panoramic IR image and I must remember not to use AWB for the individual shots.

I have read others recommend to do what you do, bracket IR shots. The IR shots that I have taken so far have all required exposures of longer than 30 sec and I can't set my camera to automatically bracket then. So I just check my histogram after I shoot and if nothing is blown out then I guess I've got my image.

There is a pretty stone bridge with five arches not far from Ottawa and tomorrow afternoon I will go there with my ND filters and IR filters. I will convert the result and see which gives the better black and white photo. If I find a composition that I like then I will go back early some morning for a sunrise shot and try the filters then too. I'm interested to see how they all compare.

Off to Pakenham to shoot the bridge there?

The "secret" in shooting panos is that everything should be done in manual. Turn off auto focus, auto ISO and shoot in manual mode. From an exposure standpoint what I always do is find the brightest part of the scene and use that as my correct exposure. I would be tempted to shoot at f/11 (or f/8 if you need a shorter shutter speed), if possible because the IR focus is not the same as focusing with visible light, so you need a bit more leeway.

You will need the same exposure from frame to frame to ensure that the blend is consistent from frame to frame.

As you are likely to be shooting from the north side of the river, near the parking lot, you will probably need to get the no-parallax point right.

[William W]

. . . The IR shots that I have taken so far have all required exposures of longer than 30 sec and I can't set my camera to automatically bracket then. So I just check my histogram after I shoot and if nothing is blown out then I guess I've got my image. . .

Curious -
What camera(s)?
What lens(es)?
What filter?

***

Have fun at the bridge. . . I'd like to see the results

. . . It was a good reminder because I want to make a panoramic IR image and I must remember not to use AWB for the individual shots. . .

I have found that panoramas in IR seem 'different' in Post Production (to 'normal' panoramas) - I can't put my finger on what it is exactly.

In any case, with my Fuji X100s, I have thus far limited myself to panos (horizontal) with only one stitch.

WW

[CatherineA]

Off to Pakenham to shoot the bridge there?

The "secret" in shooting panos is that everything should be done in manual. Turn off auto focus, auto ISO and shoot in manual mode. From an exposure standpoint what I always do is find the brightest part of the scene and use that as my correct exposure. I would be tempted to shoot at f/11 (or f/8 if you need a shorter shutter speed), if possible because the IR focus is not the same as focusing with visible light, so you need a bit more leeway.

You will need the same exposure from frame to frame to ensure that the blend is consistent from frame to frame.

As you are likely to be shooting from the north side of the river, near the parking lot, you will probably need to get the no-parallax point right.

Thank you for the pointers, Manfred. I had concerns about perspective wonkiness when stitching the images, particularly with the subject being shot on such an angle, but I didn't know what to do about them. I've just looked "pupil entry point" and parallelex. I was going to shoot with my 100-400mm at 100mm but I don't have a nodal slider. I could try the 55mm and use that part of the tripod that you are not suppose to use, that rod that gives extra height. It could support the 55mm easily but probably would shake during such a long exposure.

I think I will skip the pano for now. It would have taken me a lot of time to try to get those shots and I'm glad that I won't waste that time on what were sure to be disappointing images.

[CatherineA]

Curious -
What camera(s)?
What lens(es)?
What filter?
WW

Hi Bill,

I have one camera, the Sony a7r3.
I have a filter for the Sony 55mm.
The filter is the Hoya 850nm and that wavelength explains the long exposures.

In Feb, before all of the world changed, we were in South Carolina and crumbling cemeteries with Spanish moss seemed great candidates for IR shots. So, not very bright locations - not like a water scene mid-day would be. I got the filter at about the time we left.

I am going to try a Hoya 720nm that will fit on my Sony 100-400mm lens. I'm not sure yet whether that is a good lens for IR.

[William W]

. . .I have a filter for the Sony 55mm. The filter is the Hoya 850nm and that wavelength explains the long exposures. In Feb, before all of the world changed, we were in South Carolina and crumbling cemeteries with Spanish moss seemed great candidates for IR shots. So, not very bright locations - not like a water scene mid-day would be. I got the filter at about the time we left.

I am going to try a Hoya 720nm that will fit on my Sony 100-400mm lens. I'm not sure yet whether that is a good lens for IR.

Thanks very much for the information. I am always curious about such matters, that's one way that I learn.

My Wife has to be one of the biggest history buffs on earth, I've photographed cemeteries everywhere we travel for her research: they're exceptionally interesting - and - IMO lend themselves to IR and generally many Artistic Interpretations.

I have never had any success with IR Filters on Zoom Lenses - I am interested in your results.

I assume that the Filter Thread on your Zoom Lens is a larger diameter than the Thread on your Prime Lens, in which case, you might consider buying a Step Up Ring so you can use the 720nm Filter on the 55mm Prime Lens.

WW

[rpcrowe]

I am not keen on the false colors produced in many infrared images. Instead, I prefer the high contrast black and white images with dark skies and white foliage which can be produced by various IR filtration systems.

I decided to convert a small and easily carried (plus quite inexpensive) Sony NEX-7 mirrorless camera to full time Infrared. The conversion was done by Life Pixels and since I wanted intense contrast black and white images - I opted for the "Deep B&W Conversion" https://www.lifepixel.com/infrared-filters-choices

I chose the NEX-7 body because of its small size and light weight. When I was using Canon gear, I opted to convert a Canon D60 DSLR to full time Infrared. Although it produced nice imagery,

I did not get a lot of use from this body because the D60 was rather large and heavy resulting in my not carrying the camera very often. Additionally, although it was a crop sensor size, the D60 could not use Canon APSC lenses (the first Canon DSLR using APSC lenses was the 20D) and my primary lens for travel was the APSC 17-55mm f/2.8 IS.

OTOH, in addition to being small and lightweight, the NEX-7 can accept an e-mount lens so all of the lenses to fit my Sony 7Diii and A6600 can be used on the NEX-7. I don't need to cary extra glass.

The absolute easiest way to shoot IR with the converted NEX-7 is to have the camera in JPEG black and white mode.

Shooting in this manner, I need very little PP to get this type of image.

A downside of some full time infrared conversions is that there are some lenses which will produce a hotspot. Luckily, most of my e-mount lenses do not have this problem. I also have no focusing problems with the NEX-7 and the shutter speed is normal for the ISO selected. I will normally shoot in programmed mode and ISO 100 and the exposure is usually dead on.

This is another IR image of the moon and a tree which I did with my camera setup in the above fashion. This was shot in the daytime and I adjusted the image in PP so that the moon would not be blown out...


Of course, the least expensive way to achieve IR imagery is to physically add an infrared filter to the front of your lens. The drawback to this method is that the exposures will be very long so that, you cannot usually hand hold the camera.. Although this will nicely smooth the water in seascapes, it will cause a blur with any moving object in the frame, including foliage that is moving in the breeze. Additionally, the auto focus will sometimes not be accurate.

Another way to provide a pseudo infrared effect in an image is through post processing with Photoshop.
https://blog.spoongraphics.co.uk/fre...dobe-photoshop
I have never done this but, it looks interesting...

BTW: There used to be a camouflage detection infrared film used in aerial reconnaissance in which live foliage would be reproduced in red. However foliage that was dead for a while (such as limbs of trees covering installations and mounted on trucks and tanks) would be reproduced in black. Also false foliage would reproduce in black. This would be quite handy in discovering cehicles and installations that were camouflaged in this manner.

[William W]

. . .
BTW: There used to be a camouflage detection infrared film used in aerial reconnaissance in which live foliage would be reproduced in red. However foliage that was dead for a while (such as limbs of trees covering installations and mounted on trucks and tanks) would be reproduced in black. Also false foliage would reproduce in black. This would be quite handy in discovering [vehicles] and installations that were camouflaged in this manner.

Hey Richard, that's another blast from the past you’ve mentioned which has struck a chord with me –

At least as of a few years ago "Aerochrome" was still available to buy.

Although I knew of this type of colour IR Film for many years, it was only in the early 2000's that I got to use it. I got a gig as the second photographer, at the invitation of my friend, who, at the time was both a forensic photographer and helicopter pilot working for the Police Force.

WW

[xpatUSA]

Hey Richard, that's another blast from the past you’ve mentioned which has struck a chord with me –

At least as of a few years ago "Aerochrome" was still available to buy.

Although I knew of this type of colour IR Film for many years, it was only in the early 2000's that I got to use it. I got a gig as the second photographer, at the invitation of my friend, who, at the time was both a forensic photographer and helicopter pilot working for the Police Force.

WW

AeroChrome is still popular, um, simulation-wise. For example, shooting a Sigma DSLR without it's "dust-cover" and then finagling the result.

Go here and then look at posts by @G Radford.

For example:

https://www.dpreview.com/forums/post/63899914
.

[xpatUSA]

There is also a view, based upon theory, to set a specific 'warm' WB, (for example "Incandescent" if Degrees K is not available) there will be less likelihood of clipping. I quite like the theory but I have never tested the real life value of it.

A bit of a late response, Bill, but I was looking for something else and noticed the above.

That theory I think assumes a conversion from raw to RGB. Most such conversions from a shot made with an IR filter on the lens will result in a horribly red/magenta image. So it follows that selecting "Incandescent" WB would reduce the red content and increase the blue thereby providing a lower probability of clipping the reds. In my experience the different is minimal - just making the output more magenta but still having crushed greens.

Of course, the raw data is unaffected by the WB selection and I prefer to start from raw data in RawDigger anyway.

https://www.dpreview.com/forums/post/64802878
.

[rpcrowe]

I CHEAT

Since I want my IR images in high contrast B&W, I usually shoot my IR converted NEX-7 in B&W JPEG...

However, my smugmug.com search command has stopped working and I cannot find my Infra Red Gallery

[William W]

. . .
That theory I think assumes a conversion from raw to RGB. Most such conversions from a shot made with an IR filter on the lens will result in a horribly red/magenta image. So it follows that selecting "Incandescent" WB would reduce the red content and increase the blue thereby providing a lower probability of clipping the reds. In my experience the different is minimal - just making the output more magenta but still having crushed greens.

https://www.dpreview.com/forums/post/64802878

Thank you. Your theory on the theory, makes sense to me.

I had not thought of the association of the raw to RGB conversion.

Also, thanks for the link - I have filed it.

regards.

[revi]

But, afaik, white balance is applied after capture, and we're dealing with raw files. So how can changing the WB setting prevent clipping?
(I'm assuming clipping here means overloading the sensor, and not just having some pixels go outside the 0..255 range in post)

[pnodrog]

If the image is saved as a RAW file the only issue is exposure. If a sharp IR pass filter has been used there should be minimal exposure captured in the Blue and Green channels. With a Bayer colour filter the metering will possibly expect the green channel to provide about 50% of the exposure reading. It will depend on the exposure algorithm what bias this makes to the camera's interpretation of the exposure. If the exposure meter has built-in scene recognition it may realise it is caused by a IR filter rather than the subject being say just a red painted wall.

Interestingly some camera manufacturers make claims they incorporate scene recognition software but I have never viewed any specific information relating to it. Not that I have been interested enough to searched for it. Regardless you are discussing an exposure problem and any use of WB will only be significant if the exposure determining algorithm takes it into account.

Hopefully one of you technically driven photographers will research it all out while I'm out taking photographs....