How to shoot IR with K-x, K-5.

SRT201

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I recently figured out how to optimize my K-x settings for shooting IR using a standard R72 filter. I have always used my Olympus E-420 for IR as the 420 brightens it's liveview making it easy to frame shots without all the fuss of removing the filter, re-focusing, etc. You can probably use very similar settings on a K-5. I don't know how sensitive the K-5 imager is to IR though.

For shooting IR all that is required is a decent R72 filter that blocks almost all visible light and a camera that is reasonably sensitive to IR. Once that filter is on though your viewfinder becomes black and useless. NEVER look at the sun through the VF!

Here's how I setup the K-x with Liveview to compose my IR shots WITH an IR filter attached.

Using the Custom Image settings, you can coax the K-x into giving you a useful Liveview image. Also, the K-x Liveview CDAF system works rather well with an R72 filter. This is very important as IR light focuses differently than visible. If you focus your camera and then place an R72 filter over the lens the resulting shot will be significantly out of focus!

If you just pop an R72 on the front of your K-x and turn on Liveview all you will see is a very dark red image that is next to impossible to use in outdoor lighting for framing a shot.

So, here's the setup that will make things easier.
  • Set the camera for RAW+JPG. You HAVE to shoot RAW for IR.
  • Set the Liveview focus mode to CDAF (the B&W circle icon)
  • Set the LCD brightness to full
  • Set the AF to single center point
  • Set the AF/AE-L button to mode 2 in the Custom Settings Menu. This turns off AF for the shutter release button and uses the AF/AE-L button for locking focus.
  • Turn SR off as you will be using Liveview for framing and SR really chews up the batteries.
  • Shut off most of the liveview information like histograms as they are useless for shooting IR and make it more difficult to see the LCD image.
  • Set the drive mode to 2 second delay which locks up the mirror before shooting. You can also use the remote but make sure you are using the mirror lockup to avoid any loss of detail due to mirror vibrations.
  • Set your image preview time for a few seconds with the histogram. Having the image pop up immediately with the histogram saves a lot of time finding the proper exposure.
  • Pick the B&W Custom Image mode and make the following adjustments to it. These changes are designed to optimize the live image on the LCD for framing while shooting.
1 - Color filter set to Red. This is done to emphasize the red channel in the live image (that's where almost all of the information is being recorded anyhow). You can also try the simulated IR filter setting as well to see which gives you a brighter LCD image.

2 - Hi-key adjustment should be set to FULL Hi-Key (+4 all the way to the right).

3 - Contrast set to lowest setting (-4). Again this is to optimize the brightness of the liveview image.

You may be questioning how these adjustments will end up creating a decent JPG file. They won't. The JPG's will be throw-aways BUT the whole point here is to make the Liveview image on your LCD bright enough to frame and focus WITH the IR filter mounted.

Once you've done this you should get a usable Liveview image on your LCD so that you can see and frame your scene. In many cases you will need to help the AF system by pre-focusing on a high contrast target. Point the center focus point at something at your chosen focus distance with high enough contrast that it can easily be seen on the LCD. Press the INFO button to zoom in a few times. Press the AF/AE-L button to allow the CDAF system to lock focus. In most cases it will lock but you may have to try a few targets if your light is marginal. Once your target is locked, recompose as usual. Having a nice ball head on your tripod is handy.

When shooting in IR your red color channel is the most important since almost all the exposure takes place in red. You should never allow the red channel to clip when shooting IR (or any other time for that matter). When the K-x combines all channels to get the final B&W luminance histogram your peak values will still be those produced originally in the red channel so the luminance histogram should give you all the information you need to avoid clipping (blown highlights).

As for exposure... you are going to have to go manual. The AE system will NOT work. Set your aperture for desired DOF and adjust your shutter speed until you get the histogram of your last shot bumping up against the right side of the graph without hitting it.

Yes, you can actually get some handheld IR shots with the K-x if you push the ISO up to 400 and beyond but really... IR requires a tripod. Plan on using one to get the best results.

After this of course you have to do some work on your VERY red raw file to come up with either an interesting false color or B&W image. It's well worth it and isn't difficult once you get the hang of working with IR.

This works for an R72 filter that starts to roll off around 720nm. If you go with a deeper infrared filter like an 87 I really don't know if this will work as there is an even heavier cutoff to visible and deep red. The image on the LCD would likely be much harder to see and the AF might not work at all.

For more info... Here's an excellent source
http://www.wrotniak.net/photo/infrared/

--

Life is NOT measured by the "moments that take your breath away" anymore than books are measured by the number of exclamation marks. The whole picture matters.
 
Thanks for the very detailed explanation.

I've tried my hand at IR a few times, but I've never been able to get the red cast down to an acceptable level. I shoot in raw and correct the WB as much as possible in ACR. After converting to a jpeg, I swap the color channels in CS5. The end result is so-so, but nothing which I have been happy enough with to consider it worth the effort... neither color nor B&W.

I finally concluded that my problem must be the length of exposure -- usually in the 20-30 second range. Over that long a time, I think the sensor just collects too much red to get rid of. I've tried going up to higher ISOs, but anything over 800 wasn't very usable. (I guess the red makes for worse noise than usual, as I can normally go up to 3200 with decent results.)

So I'm wondering what a normal shutter speed is for you when shooting IR in bright sunlight.

--
-- Joe S.

"We make a living by what we get; we make a life by what we give." ~ Sir Winston Churchill

http://www.pentaxphotogallery.com/artists/josephschmitt
 
Well that depends of course on the ambient lighting but much of my landscape IR is from 2 to 6 seconds at ISO 100-200. I have shot 30s, 60s and longer with good results in dim lighting. I like to keep the noise down but always push the histogram to the right if possible to maximize my use of dynamic range.

As for being too red. That's all there really is. No matter what you do all the energy is going to collect in the red channel. Anything that collects in the Green and Blue channels is probably a result of errors in demosaicing from RAW or the fact that the green and blue filters in the bayer matrix are not perfect brick walls and so allow some lower frequency energy through. There is of course virtually no energy present in those higher frequency ranges in reality.

I have found that a good place to start is to take your very RED RAW file into your RAW converter and start adjusting the blue and green tone curves individually until you get the blue and green histograms to generally match the same horizontal range as the red histogram. This will require pulling a control point on the blue and green curves upward away from the red line (which should be left flat to start with). In doing this you are really making radical adjustments in white balance. Once you have done this you can start to play with overall contrast, B&W conversion, etc.

It takes a while to get a feel for IR RAW files but once you do it gets a lot easier. I don't even see the matrix anymore. :-)

--

Life is NOT measured by the "moments that take your breath away" anymore than books are measured by the number of exclamation marks. The whole picture matters.
 
Well that depends of course on the ambient lighting but much of my landscape IR is from 2 to 6 seconds at ISO 100-200.
Wow. Clearly I am doing something wrong, then. Mine are nowhere in that ballpark, especially at ISO 100-200.
I have shot 30s, 60s and longer with good results in dim lighting. I like to keep the noise down but always push the histogram to the right if possible to maximize my use of dynamic range.
Yeah, to my eye the noise is worse when I expose to the left at lower ISO than when I expose to the right at higher ISO.
As for being too red. That's all there really is. No matter what you do all the energy is going to collect in the red channel. Anything that collects in the Green and Blue channels is probably a result of errors in demosaicing from RAW or the fact that the green and blue filters in the bayer matrix are not perfect brick walls and so allow some lower frequency energy through.
While I don't claim to understand all the electronic processes of digital photography, I wonder if my overly-long exposures allow more of an opportunity for that to happen?
I have found that a good place to start is to take your very RED RAW file into your RAW converter and start adjusting the blue and green tone curves individually until you get the blue and green histograms to generally match the same horizontal range as the red histogram. This will require pulling a control point on the blue and green curves upward away from the red line (which should be left flat to start with). In doing this you are really making radical adjustments in white balance. Once you have done this you can start to play with overall contrast, B&W conversion, etc.
I'll have to give that a try. Other than briefly during a Photoshop overview course that I took a few years back, I've never really fooled around with curves much. With IR jpegs, I usually just do an auto adjustment for the curves, which I found made a big improvement. So maybe if I follow your instructions, I'll have even better results. There's always something new to learn in Photoshop.
It takes a while to get a feel for IR RAW files but once you do it gets a lot easier. I don't even see the matrix anymore. :-)
It's funny that you posted this thread now. A few weeks ago I was cleaning out my photography stuff and looking to see if there was anything I could sell off. Immediately I thought of my IR filter. I just never use it anymore because I can't get satisfactory results. So it's on eBay now. Now watch me try your suggestions, find that I really do like IR, and then somebody buys my filter. =)

Either way, thanks for the tips.

--
-- Joe S.

"We make a living by what we get; we make a life by what we give." ~ Sir Winston Churchill

http://www.pentaxphotogallery.com/artists/josephschmitt
 
I have shot 30s, 60s and longer with good results in dim lighting. I like to keep the noise down but always push the histogram to the right if possible to maximize my use of dynamic range.
Yeah, to my eye the noise is worse when I expose to the left at lower ISO than when I expose to the right at higher ISO.
Your eye is correct. Exposing to the left is ALWAYS a bad idea if it can be avoided. You should ALWAYS push the histogram as far to the right as possible. We engineers call it signal to noise ratio. The closer you get to the right, the greater your signal to noise ratio. The greater your SNR, the less obvious the noise will appear. It's that simple. Yes... a shot with the histogram pushed to the right can look very washed out in a simple OOC JPEG but drop the exposure back or do simple curve adjustment and you end up with a far superior image with much lower noise.
As for being too red. That's all there really is. No matter what you do all the energy is going to collect in the red channel. Anything that collects in the Green and Blue channels is probably a result of errors in demosaicing from RAW or the fact that the green and blue filters in the bayer matrix are not perfect brick walls and so allow some lower frequency energy through.
While I don't claim to understand all the electronic processes of digital photography, I wonder if my overly-long exposures allow more of an opportunity for that to happen?
Nope... long exposures simply allow more photons to fill the quantum wells of each pixel site thus charging it up. Which photons get there is dictated by the Bayer filter and the light frequencies given off by the subject. As long as those pixel sites don't saturate (quantum bucket overflows) then the only other difference with long exposures is that they allow more of an opportunity for dark-currents in the imager to create hot pixels. That is why most cameras allow for a "long shutter" noise reduction to be employed.

In any case, the length of exposure should not cause any color shifts unless you saturate a color channel (blow it out) in which case the shot is ruined anyhow because information is lost.

--

Life is NOT measured by the "moments that take your breath away" anymore than books are measured by the number of exclamation marks. The whole picture matters.
 
I have found that a good place to start is to take your very RED RAW file into your RAW converter and start adjusting the blue and green tone curves individually until you get the blue and green histograms to generally match the same horizontal range as the red histogram. This will require pulling a control point on the blue and green curves upward away from the red line (which should be left flat to start with). In doing this you are really making radical adjustments in white balance. Once you have done this you can start to play with overall contrast, B&W conversion, etc.
If you have time, could you elaborate a little more on this, particularly the part I put in bold?

When I got home this afternoon, I took a few test shots following your method. It definitely helped to be able to see and focus with the filter attached. And I was able to get shots at 2-3 seconds at ISO 200. (I still don't know what was causing my long exposures before, but as long as it's working now...)

Anyway, when I loaded them into ACR to begin processing, I went to the Curves adjustment tab. I have to admit, I am lost at that point. Not completely, as my mathematical training makes me comfortable with the whole input-output design. But I'm not sure which point corresponds to which color. In some cases, I can see a more pronouned change in one color than the others, so I would suppose that would be the tell. But in some cases the change seems about the same in multiple colors. Also, I'm not sure what you mean by left flat -- do you mean left along the 45-degree diagonal so that no changes are made to it?

Thanks for your help. I'm at least better off than I was before, as I now am getting a more reasonable shutter time.

--
-- Joe S.

"We make a living by what we get; we make a life by what we give." ~ Sir Winston Churchill

http://www.pentaxphotogallery.com/artists/josephschmitt
 
Well I don't have ACR but from what you are telling me you are adjusting the Luminance curve (all three channels at once). There should be an option on ACR's curve tool to adjust just a single channel. Leave the red channel alone to start with and adjust the green and blue channels individually till you see the histograms starting to overlap. You also have to be able to see all three histograms - which I assume ACR will show you simultaneously.

--

Life is NOT measured by the "moments that take your breath away" anymore than books are measured by the number of exclamation marks. The whole picture matters.
 
Well I don't have ACR but from what you are telling me you are adjusting the Luminance curve (all three channels at once).
ACR calls it Tone Curve. When I go into that section, there is the option for Parametric or Point. Parametric has four sliders: Highlights, Lights, Darks, and Shadows. Point seems to match your description a little better, as it shows the curve with moveable points on it.
There should be an option on ACR's curve tool to adjust just a single channel.
That's what I was looking for, but I haven't found it yet. I'll do a more extensive internet search when I have time.
Leave the red channel alone to start with and adjust the green and blue channels individually till you see the histograms starting to overlap. You also have to be able to see all three histograms - which I assume ACR will show you simultaneously.
Yes, it shows one combined histograms with all colors.

I think the main thing I need to determine first is which moveable point belongs to which color.

At any rate, thanks again for giving me a new perspective on this. Just being able to see the live view image while shooting is very helpful.

--
-- Joe S.

"We make a living by what we get; we make a life by what we give." ~ Sir Winston Churchill

http://www.pentaxphotogallery.com/artists/josephschmitt
 
Leave the red channel alone to start with and adjust the green and blue channels individually till you see the histograms starting to overlap. You also have to be able to see all three histograms - which I assume ACR will show you simultaneously.
Yes, it shows one combined histograms with all colors.

I think the main thing I need to determine first is which moveable point belongs to which color.

At any rate, thanks again for giving me a new perspective on this. Just being able to see the live view image while shooting is very helpful.
No problem. IR requires playing around to get the hang of it and unfortunately each RAW tool is different since none of them are really designed around IR photography. I use DxO Optics Pro 7 and generally it's very good. It has it's own idiosyncrasies. No camera is perfect, no imaging tool is either. :-)

Cancel your filter auction and stick to it for a while. I think you'll find it's worth it. I really enjoy IR because it allows me to explore a different world of photography that not many venture in to.

I always wanted to do it in the film days but it was prohibitively expensive and difficult back then. Digital has made it easy - relatively speaking.
"We make a living by what we get; we make a life by what we give." ~ Sir Winston Churchill
Wish we had some read leaders like him around these days.

--

Life is NOT measured by the "moments that take your breath away" anymore than books are measured by the number of exclamation marks. The whole picture matters.
 
As for being too red. That's all there really is. No matter what you do all the energy is going to collect in the red channel. Anything that collects in the Green and Blue channels is probably a result of errors in demosaicing from RAW or the fact that the green and blue filters in the bayer matrix are not perfect brick walls and so allow some lower frequency energy through. There is of course virtually no energy present in those higher frequency ranges in reality.
After looking at the histograms and thinking further I'm pretty sure that RAW conversion errors contribute little if any to the green and blue image content when taking an IR shot. Looking at the histograms it's pretty clear that the IR filter is simply allowing enough light through to register at those frequencies. As expected the green histogram contains only a small fraction of the energy in the red histogram and the blue only a small fraction of the green as the filter continues to roll off.

--

Life is NOT measured by the "moments that take your breath away" anymore than books are measured by the number of exclamation marks. The whole picture matters.
 
Thx for the detailed instructions.

I've tried using R85 that I was given by my friend on K10 and K5 but without any success (although it seems that K5 has weaker IR filter).

I've just ordered a cheap R72 Hoya-like filter from e-bay and I'm going to follow your instructions. Hopefully I'll get some results.
 
I don't know about ACR and I don't know about Lightroom 4, but Lightroom 3 does not allow you to adjust color channels individually. I consider this a black eye for LR. Kinda hard for me to tell if they added this in LR 4...
There should be an option on ACR's curve tool to adjust just a single channel.
That's what I was looking for, but I haven't found it yet. I'll do a more extensive internet search when I have time.
 
Very good notes and I will bookmark them, thanks.
If you focus your camera and then place an R72 filter over the lens the resulting shot will be significantly out of focus!
My old Canon film lenses have a mark on them and this mark is an offset to use so focusing with IR film will be correct.
 
The old focusing scale helps but not as precise as the CDAF.

--

Life is NOT measured by the "moments that take your breath away" anymore than books are measured by the number of exclamation marks. The whole picture matters.
 
Thanks for your detailed IR guide!
This is definitely a bookmark post, now all i need is an IR filter!

--
-----------------------------------------------
Miles Green
Pentaxian with chronic LBA
Corfu, Greece
 
Well, this is nice. Individual color channels can be adjusted in Lightroom 4:
http://www.dpreview.com/articles/7481161037/lightroom-4-review/2

"In Lightroom 4's Tone Curve panel you can make Point Curve edits to individual RGB channels, a task that until now required a trip to Photoshop."

For a premium image editing package, I thought it was odd Adobe did not previously allow this.
I don't know about ACR and I don't know about Lightroom 4, but Lightroom 3 does not allow you to adjust color channels individually. I consider this a black eye for LR. Kinda hard for me to tell if they added this in LR 4...
There should be an option on ACR's curve tool to adjust just a single channel.
That's what I was looking for, but I haven't found it yet. I'll do a more extensive internet search when I have time.
 
Cancel your filter auction and stick to it for a while. I think you'll find it's worth it. I really enjoy IR because it allows me to explore a different world of photography that not many venture in to.
Too late. Someone already bought it. I sold it for $5 more than I bought it for two years ago, so with shipping and eBay fees I pretty much broke even.

In the two years I've had my K-x, I hadn't bought a good quality ND filter -- I was still using my old un-coated one from film days (when I shot, coincidentally, an SRT 201). So I used the proceeds to order a good ND filter, which to be honest I will use much more than the IR.

Even so, thanks again for posting this thread. Maybe it will get some more folks interested in this field of photography.
"We make a living by what we get; we make a life by what we give." ~ Sir Winston Churchill
Wish we had some read leaders like him around these days.
Yeah, that would be nice. And sadly, it doesn't look like we have any coming down the road any time soon.

--
-- Joe S.

"We make a living by what we get; we make a life by what we give." ~ Sir Winston Churchill

http://www.pentaxphotogallery.com/artists/josephschmitt
 
MAKE SURE you pick up an R72. The R72 is mostly IR and near IR with a little deep red as well. This works well with the K-x and presumably the K-5 AF system and built in IR filters.

I recently picked up a deep red 850nm IR filter to play with. That is a completely different game! You would have to focus first with an R72 filter because the AF system will not work with a filter like an 850. There will be virtually NO image at all on the LCD. Also, the exposures are MUCH longer.

So if you haven't done any IR before... stick to the venerable R72 for your first try.

--

Any government that has the power to correct any injustice and level any inequality also has the power to do ANYTHING it wants.
 
In my experience, I have found the older cameras with the 6 mp sensor to have weaker IR barriers. Using a *istD, I have generally been able to get proper exposure at 6-7 stops below normal using an R72. I'm not sure that the later models such as the K100D had the weak IR filter, though.

Using an m50mm f/1.4 on a tripod, I got good exposure at 1/5th second f/11 (?) on this shot:
http://jamesrobins.phanfare.com/5346622_6044806#imageID=143118289
Processed in LR at 2000 color temp.

--
JNR
http://www.jamesrobins.com
 
Wow! Glad I didn't pick up LR3. That's terrible!

--

Any government that has the power to correct any injustice and level any inequality also has the power to do ANYTHING it wants.
 

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