Anyone use their Pen-F with an IR filter?

bargainguy

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The frequency of the filter is not the issue.

You're butting up against the limited IR sensitivity of the camera / sensor combo when you leave the low-pass filter in place and attach an IR filter on the lens.

Removing the low-pass filter - infrared conversion - would let much more of the IR spectrum through and produce much more IR reflectivity, so you get the white foliage you're looking for. Leave the low-pass filter in place, and only a little IR leaks through.
 

ColinM

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Did someone say IR with a DiMAGE 7? Wonderful device, and my first digital too. Just for fun, here are a few from back in the day - 2004 - with R72 filter.

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Now I shoot IR with a converted GH3, and It's definitely the way to go if you are really keen.

Colin
 

Mack

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Did someone say IR with a DiMAGE 7? Wonderful device, and my first digital too. Just for fun, here are a few from back in the day - 2004 - with R72 filter.

Nice shots!

Did you have the Dimage 7 converted to shoot IR by removing the sensor's filter?
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Aside, some are saying to set the White Balance first. I had the Pen-F on AWB and sometimes 5200 Kelvin manual.

I went into the SCP and scrolled to the Capture White Balance icon (i.e. Two triangles with a bubble in middle and a 1 next to it.) and I shot a white balance card near my desk lamp. A warning popped up saying something like "The setting is extreme. Do you wish to continue, YES or NO?" I hit YES to save it. That got rid of the reddish cast of the IR filter and looks as it should. So now I have a neutral WB with the IR filter in place without the strong reddish cast normally seen once shot.

I have one of those "Expodisc" things for WB and may use it if the sun doesn't play nice today with the WB card.

Now to wait for the fog to lift and search out a green tree someplace.


Also, someone has gone through the Olympus lenses on "Hot Spots" (That's new to me too!) if doing IR shots. https://robertreiser.photography/olympus-lens-infrared-performance/ I got lucky with the 12mm other than the normal vignette it does wide open at f/2.
 
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ColinM

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Nice shots!

Did you have the Dimage 7 converted to shoot IR by removing the sensor's filter?
Thanks, Mack!

No, it was just as normal with the R72 (720nm) filter on, with the EVF making all the difference from shooting Kodak HIE through an IR filter. The DiMAGE 7 had a fairly weak IR stop filter, so shutter speeds were usually less than 1s at 100 ISO in sunlight. The downside of the weak filter was that when shooting colour in sunlight, black clothes could often look a bit odd. My GH3 has the IR stop filter replaced by an R72 equivalent, so exposures are normal.

Colin
 

Petrochemist

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I've not used a PenF but I've shot IR with Panasonic MFT cameras, both stock & converted.
With the stock bodies you end up with fairly long exposures even when shooting outside in fairly good light. Hand holding was possible using the G1 with fast lenses, once I had the converted body I only used stock bodies for IR if I wanted long exposures. Reaching 30s (a September afternoon in London) was easy only needing f/8 at base ISO.
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Distant London EyeR by Mike Kanssen, on Flickr

I would expect the PenF to behave in a similar way, though there could be a couple of stops difference in IR sensitivity.
 
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PakkyT

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What I've learned is the IR takes on some serious post work to get them to look good.

Yes this is one drawback to IR shooting. There is almost no such thing as a straight out of the camera image that is "sharing ready". Only on my old C-2020Z did I get some SOC shots I liked, but later models have always required some level of post processing. So IR shooting is not for those who like to press the shutter only and hate post processing.

I have been using GIMP for some years for a lot of my IR work since it is free and support channel swapping. But lately I have been playing with darktable as well. I still think I get better IR white balance out of GIMP though. The nice thing is on my Mac, GIMP uses darktable now as a front end to open the .orf files where I can try some darktable adjustments and then when done and you close darktable it passes the image on to GIMP. So if darktable isn't doing it for me I can simply move on to GIMP. In either case the workflow ends up being the same.


However, I do not seem to get the white leaves in trees that some IR photos show. Could be I need something stronger than a 720nm IR filter,

No just a matter of setting your custom WB correctly or adjusting white balance in post. I have always shots 720nm and 750nm with my latest and never had issues with getting white foliage most of the time.


I have one of those "Expodisc" things for WB and may use it if the sun doesn't play nice today with the WB card.

IR WB is very different from normal visible spectrum WB so you often can not use visible spectrum WB tools for IR white balance. As I mentioned somewhere are here (can't remember if it was this thread or not), I usually custom WB off a patch of lawn/grass and save that as my baseline with final WB tweaking in post, but this gets me about 90% of where I expect to be with WB coloring in my IR shots. Shooting in RAW I can always change my mind later.
 
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Mack

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Thanks PakkyT. I think you are right as this IR stuff takes some creative headaches, er editing to get through it all.

Managed to set a white balance card off the back of a video color calibration card. Not a great sunny day though. The Pen-F protested with: "Are you sure about extreme color?" but I saved it.

Back into Olympus workspace with a better - or less reddish - IR shot. Still Workspace refused to Save my settings for a Batch File Preset. Uninstalled Workspace v1.4 and re-installed it and it works as it should. Now I can save Batch File Presets again. Yay!

Still, my greens are not going to white and sky isn't as black as it should with the Amazon Green L 720nm IR filter. I put the filter onto the x-rite i1 PhotoPro 2 head and using Argyll's color meter app I got its curve. Seems to pass some light beginning around 620 up to 710nm so who knows. Might be a bit weak for IR. I can see a flashlight through it. Curve is below.

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An old Red #25 filter was nearby and produced the curve below so not much there, but it was from film era and I was just curious as to its curve.

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Then I put the Kodak Wratten 87C IR gelatin filter on it and it threw a fit! All noise, but that filter is opaque as heck and I cannot see any flashlight through it. I think it is maybe 800nm or so. The Wratten 87C curve below is a mess, and likely the x-rite spectrometer head wasn't suited for that filter.

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I'll await the Neewer set of four different IR filters (720, 760, 850, 950nm or so they claim.) next week and see if they make any difference.
 
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Petrochemist

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The 720nm filter should work fine for IR. Yes you see a trace of transmission in the visible red but if you look at the scale of the plot this is less than 1%. A 720nm filter will transmit around 50% at 720nm (thats how the classification works) above ~750nm it will transmit over 90%.

FWIW I have a similar set. All with the exception of the 950nm are reasonable close to the listed 50% transmission values and show fairly sharp transitions (typically 30nm, either side).
The '950' starts transmitting below 850nm (reaching 1% at 837nm) and has a very gradual slope, only reaching 33% at 950nm and 71% at 1100nm. The spectrometer at work doesn't go any further, but converted cameras don't either as Silicon becomes transparent to IR at 1100nm :).

I have been able to get images with all 4 of the set using my old unconverted DSLR. I probably haven't tried them all on stock MFT bodies.

According to Kodak's data the 87C doesn't start to transmit till 800nm, and reaches 50% transmission around 860nm.

It's a shame the Argyll Pro colour meter doesn't record values further into the IR, but I suppose for their target market that information is irrelevant.
Spectra like these can be very useful - especially if you want to record UV. Most UV pass/visual blocking filters transmit enough IR to mask any photographic details from UV even using a 'full spectrum' converted camera. This leakage was irrelevant in film days but is a pain today unless you're able to spend several hundred on the filter.
 

Mack

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I gave up on the Pen-F. :(

The "IR look" from it just cannot match the Dimage 7 with its less restrictive - albeit not perfect for IR - spectrum filter. The Pen-F sensor must have a much narrower visible light spectrum and causing the extremely long exposure times with the sundry IR filters.

However, the old Dimage 7 is also showing a lot of white hot pixels too given it's 20 years old. With B&W IR SOC, it looks like someone sprinkled white sand all over the images. No mapping available to fix that given its age and buh-bye Minolta service.

So I bought a used OM-E1 Mark I at the lifepixel.com site and will have them convert it to 'Full Spectrum" since I bought a bunch of IR filters already and have step-rings for the Olympus lenses. About $650 or so. Wasn't planning on buying another Olympus product, but there goes that plan having too much of their glass. :dash2:
 

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