Cheap R72 Filter

Discussion in 'Nikon' started by chip_chipowski, Oct 2, 2014.

  1. I saw an 77mm Opteka R72 filter on my local classifieds for $5, so I had to buy it. I plan to use it on a tripod for landscapes. Taking handheld shots on the way back to the office was an adventure, because the viewfinder is essentially blacked out. I have seen some cool pinhole escalator shots, so I tried one using the new filter.
    I am not expecting anything special from this particular filter, but I'd like to have fun with it. Maybe I will get my D200 converted to IR.
    If anyone has experience using an R72 filter:
    1. Do you have advice re any focus shift?
    2. Any other tips or comments re metering tricks, etc?
    3. Bad idea to use it on D300?
  2. First shot is ISO 1000
    Portlandia is ISO 1600
  3. Street crossing. These are all processed in LR with Silver Efex Pro 2.
  4. Wells Fargo
  5. Obviously vignetting is a presence at 12mm
  6. 1. Do you have advice re any focus shift?​
    If your style is mostly creative use of soft focus and motion blur, don't worry about focus shift. In most cases it's negligible other than for close ups with fast lenses shooting wide open. Most IR photography is inherently soft anyway. Flare, hot spots, diffraction, etc., all conspire to thwart most efforts at razor sharp focus anyway.
    I mostly use a 24mm f/2.5 Tamron Adaptall for IR on my D2H. I've needed to shift focus very slightly on a few closeups. Usually I stop down to f/4-f/8 and don't bother to use IR shift unless I see an obvious focus problem when reviewing the photo on the rear LCD.
    And I do a lot of long exposure stuff with IR, looking for interesting motion blur patterns in foliage. So I don't worry about critical sharpness in most of my IR photos.
    For cameras with live view and the ability to display a usable image through IR filters, just focus until it looks right.
    2. Any other tips or comments re metering tricks, etc?​
    Depends on the camera. My D2H meters with remarkable accuracy through my combination of filters for infrared. I mostly use aperture priority and let the camera handle the shutter speed - occasionally I'll dial in a little exposure compensation, usually only 1/3 EV plus or minus. The most essential trick is to block the eyepiece. If your camera doesn't include an eyepiece blind, rig up something to block it during exposures.
    Some folks insist on using only manual exposure with IR. To me this seems pointless. Aperture priority works very well. And it's impossible to accurately meter while peering through the viewfinder anyway. The eyepiece must be blocked. Without access to the viewfinder my only way to determine the correct manual exposure settings is to peek at the top mounted LCD. This is impractical when I have the tripod above eye level. It's easier to just trust aperture priority and make minor exposure comp adjustments. A camera with live view would offer other possibilities.
    Another trick: Try to white balance through the lens with the IR filter in place. This makes post processing easier. My D2H struggled with auto white balance, and I wasn't sure how much to tweak WB in Lightroom to get the desired false color or b&w IR results. So I tried WB through the lens on a sheet of white paper. This pegged the D2H custom WB at the limit of 2500K. Finally the JPEG previews looked right on the camera. In Lightroom I usually adjust the WB to 2000K, and shift the tint toward green.
    And try more than one raw converter. I tried IR tweaks of my Nikon NEFs in Lightroom 4.4, RawTherapee, Photo Ninja, Silkypix and even in Picasa. Only Lightroom provided the results I wanted. But results might be different with another IR converted camera.
    3. Bad idea to use it on D300?​
    LifePixel and other companies that specialize in IR conversions say it doesn't matter. All digicams are more or less equally sensitive to infrared. It's the filter pack over the sensor that determines IR sensitivity.
    My D2H is sensitive enough without any modifications. The D2H always had a notoriously weak built in IR blocking filter, which made it a poor choice for color photography under some artificial light - the excessive sensitivity to near-IR made skin colors ghastly and cadaverous under most fluorescent and metal halide lights. Other cameras have more effective hot mirror filters. But once the filter pack is removed it's moot. So your D300 should work fine if you decide to have it modified.
    If I get serious about IR I'll probably just buy an already converted camera. Some folks tire of the novelty and sell their professionally IR converted cameras, so eventually I'll look for one of those.
  7. If you're going hand-held don't worry about focus shift, your exposures will motion blur unless you're on ISO crazy.
    For tripod stuff, you could try LV AF. My D90 would sometimes manage LV AF with a 720nm filter before I IR converted it, but never managed with anything over 850nm. Once converted, it LV AFs at all wavelengths.
    However, most of my hot-spot free lenses are MF, so I manually focus in zoomed LV. Most of my stuff is kinda forensic related under narrowband IR LED lamps and I'm not often outside. That being said, the Sun produces a humongous amount of broadband IR, so trees & foliage etc is quite easy.
    Handily, the older MF lenses have the small red focus IR focus offset dot, which is helpful for grab shots. I can't remember what wavelength it's set for, but it shows you the right direction! I'd assume it was for the peak sensitivity of High-Speed B/W and IR transparency film which I think was above 800nm??
  8. Another trick: Try to white balance through the lens with the IR filter in place.
    So I tried WB through the lens on a sheet of white paper​
    If trying to WB, then it works mostly better when you do that on green foliage, or better on grass , THis helps because the the brightest IR reflection you will get from grass.
    Alternatively : Indoors Open fire ( from burning wood) works excelent to for WB for IR ....
  9. I have a 52mm Hoya R72 somewhere. It also cost me next-to-nothing. Used it a half dozen times and really couldn't see the point. Mine gives a big magenta circle in the middle of the image, which precludes its use for colour "IR" use. When converted to B&W the IR effect isn't too convincing either, and I'm pretty sure that a simple action in PS could duplicate the effect almost completely without the inconvenience of not being able to see what's in the viewfinder.
    Anyhow, have fun until the novelty wears off Chip!
  10. I was just inspired to have a go at creating a pseudo-IR in GIMP. Not the best program to use since its Hue-Saturation tool is decidedly broken, but it did a reasonable job. Working with PS would definitely have given a better result, and the reason I didn't use PS is because I don't have it installed on this laptop.
    I don't think the result is too bad though. Looks very IR-ish to me. I just altered the lightness of the green and yellow channels, and then played with the curves after converting to B&W.
  11. Incidentally, it's possible to do digital IR without a dedicated IR filter - I've described this before so I'll try to abbreviate it...
    Several years ago I read about a trick for using two stacked polarizers to block visible light for a makeshift IR effect. I may have read about that on Bjorn Rorslett's site, years ago when I was considering buying the Nikon D2H. Bjorn's sections on alternative light photography are very interesting, particularly on UV photography.
    I tried it on my D2H but the results didn't resemble the IR I expected, and I wasn't sure how to process the raw files, so I gave it up. However this year I was prowling through the box of rocks every photographer eventually accumulates and found a long neglected #25A red filter that I hadn't used since I shot mostly b&w film. I never cared much for the melodramatic effect of a red filter on b&w so I used it only a couple of times.
    The 55mm red filter was purchased for my old Canon FD gear - long since gone - and fit only one of my current lenses, the Tamron Adaptall 24/2.5. On a lark I put it on the D2H, then stacked a set of Cokin sheet filters with two polarizers. This finally got the IR effect that had been missing from my earlier experiments that had omitted the red filter. The best results came from a combination of a Cokin neutral circular polarizer and one of Cokin's oddball multi-color polarizers, the Pola Red-Green (no relationship to the Canadian comedy TV show, other than the devotion to makeshift solutions involving duct tape). Substituting the Pola Purple-Orange didn't work as well. And the orientation of the multi-color polarizers didn't matter. Only the orientation of the circular polarizer mattered.
    The advantage to this trick is that it isn't necessary to remove the filters to compose and focus. Just twist the circular polarizer to the "open" or brightest position - it's clearly visible through the viewfinder. It will still be a bit dim and very red, but clear enough to see in most daylight, even early in the morning or toward sunset. After composing and focusing, twist the circular polarizer "shut" until it's as dark as possible. Close the eyepiece blind, and let the aperture priority mode handle the rest.
    Now, it's possible this trick won't work with another camera - it may be a quirk unique to the D2H which was always excessively sensitive to near-IR anyway. I'll have to try it on my Nikon V1 and Fuji X-A1, now that I have adapters to accommodate the same Tamron lens and filter stack.
    Having to remove the conventional IR filter for composing and focusing, then replacing the filter, may be part of the hassle that eventually causes SLR/dSLR users to tire of the novelty. Some folks seem to prefer mirrorless models or cameras with accessory finders or rangefinders. But the polarizer trick helps minimize the setup hassles using a dSLR, and for several months I've just left the entire rig on my D2H for tripod mounted IR photos. However the more recent IR-converted mirrorless models would be much more convenient for handheld or more spontaneous IR photography. I'm seeing these IR-converted mirrorless cameras used for photos of people walking, free of motion blur from the people or foliage. That's a huge advantage over the older method of viewfinder-blackout-filters and slow shutter speeds or cranking up the ISO to compensate. So there's still some life left in the IR game beyond the familiar gee-whiz lookit them white trees pix.
    *Infrared with unmodified D2H and makeshift filter combination of #25A red, and a pair of Cokin polarizers. The "Wood Effect" white foliage comes through, depending on preferred white balance. There's some hot-spotting - most notably in the center of the wall with diagonal shadows - but it resembles the vignetting effect from Lightroom and other editing software. A reverse or lightening vignetting effect could be used to negate hot-spotting, or the lens correction tool could be used.
  12. Nice looking shots, Lex.
  13. Tri Cities Area - WA
  14. Umatilla, OR
  15. Columbia River Gorge
  16. Heppner Highway - OR
  17. So a couple of things. The R72 is just starting into IR ranges. There is still a lot of red contamination. Look for a 092 if you want deeper IR.
    Some lenses are better at IR then others. The problems are some lenses just do not focus well in IR. My 35mm f/1.4 AIS just sucks in IR and that is using an IR filter on unmodified cameras or using it on my modified cameras.
    You also have to check for an IR hot spot some lenses show it no matter what and other lenses only show it when you start to stop them down.
    IR with modified D200 and Sigma 35mm f/1.4 at f/8
    Focus shif it less of a
  18. Wow! Looks like you've been busy with that filter Chip. Did you use it straight or take Lex's advice to combine it with a #25 red?
    I'd like to see comparisons with straight B&W shots though. Since I'm still not convinced that the IR look adds anything apart from some novelty value. A good tonally-adjusted straight monochrome shot would probably still get my vote, as long as the composition and subject are the same. Just had a thought: I might try layering negative and positive layers and locally erasing or adjusting the opacity to get a similar strange effect to IR.
    Also, did anyone reading this ever use IR film? I don't recall "hot-spotting" being mentioned as an issue with IR film. So is it a digital only phenomenon? And if so - what's the score with that?
  19. Good photos, Chip. I particularly like the spare composition of the sloped landscape, and the dramatic ghosting flare across the highway. I need to try that effect again with my IR rig, just to see what the ghosts look like in color IR.
    Hot spots are common with IR film too. The challenge was discussed and cussed often way back when. I'm not sure about the techie stuff - there's some speculation in this 2005 thread.
    A common recommendation is to shoot wide open, which seems to confirm the theory that at least some hot spots are due to reflections between the closed diaphragm and front elements, back onto the recording medium. It's possible - maybe probable - that highly reflective digital sensors exaggerate the hot spots more than film did.
    Some dedicated IR photographers will try many lenses to find one or two that cooperate with IR. I've been pleased with the Tamron Adaptall 24mm f/2.5 so I haven't bothered to try another lens yet for IR. The approx. 36mm equivalent view on a DX dSLR suits my preference for most landscapes and general photography. The hot spot is subtle enough to resemble natural light falloff toward the edges, or a vignetting effect applied in post. And the edges are feathered enough that I could offset it by applying reverse/positive "vignetting" or lens correction adjustments. But it hasn't bothered me enough to try either method. The same effect is visible in Chip's photos (assuming no vignetting was applied in post).
    RJ, I know what you mean about the challenge to finding a unique vision with IR photography. There's so much gorgeous landscape IR photography already, b&w and color, film and digital, I really didn't want to explore that beyond a few test photos to see the novelty effect of white foliage.
    After that the first thing I did was to start shooting outside the prime IR hours. I mostly shoot near dawn (yeah, right, like I'm ever up that early - maybe twice this summer) or near sunset. The foliage is more light gray than white, and in color leans bluish. The effect is less obviously IR-ish and somewhat disorienting. I've particularly enjoyed the effect on an enormous boletus mushroom in a nearby field that has been remarkably well preserved over the summer - it sprouted during our uncommonly moderate spring and was almost immediately dehydrated by a sudden shift toward hot, dry winds.
    That same field - actually a long abandoned commercial lot - has slowly reverted to native prairie, with a nice crop of wildflowers this year, along with lush wild sage and other native grasses and stuff. It's been interesting to see how each differs in IR. The sage tends toward classic Wood Effect white, while others go gray. And the dried grasses and brush tend to retain a more natural color.
    Mushy, au naturel avec Gollum
    Mushy, au unnaturel
  20. The big advantage to IR for B&W landscapes is that it will cut through any haze.
    Take a look at this shot from Nova Scotia.
    No haze
  21. Lex, did you travel all the way to Cottingley to get those shots?
  22. Alas, never been to Cottingley. The closest I've gotten is the lovely and sad movie "Photographing Fairies". Great movie, terrible trailer.
  23. Thanks for all the comments and contributions.
    RJ - No filter combination, just the R72.
    I had fun playing with the filter, and it is nice to have if I want it. I like long exposures, that aspect of the filter is interesting. It is a little cumbersome to have to remove the filter when setting up your composition. I like the effect generally - I think I'll get my D200 converted at some point. I have a Nikkor 28mm f/3.5 Type K and Bjorn Rorslett rated it highly for IR.
  24. A few more experiments in infrared terror with the D2H and various combinations of polarizers and other filters. While messing around I noticed some parts of the black finish on my Ricoh Caplio GX100 came out light gray under infrared. The plastic grips and top plate remained black. If I'm recalling correctly the Ricoh's main body is magnesium, which the rest is aluminum or plastic. There were also some distinct differences in clarity of details, such as the lettering, depending on how the filters were set up.
    These were done with a 50mm f/2 AI Nikkor and various filters. There's a very narrow sweet spot for sharpness, between f/4-f/8. Wide open at f/2 was very soft, with noticeable vignetting, but that's normal for this lens. Vignetting cleared up by f/4 and there was no noticeable hot spotting. By f/11 diffraction goes to hell. It wasn't a gradual change but a sudden shift from very good sharpness to near-pinhole softness. I haven't read enough about IR to know the physics behind the diffraction effects. These were all shot at f/4, although some meta data readers show it as f/3.8 or just f/3. I'm going to run some more aperture tests in daylight to see if sunlight effects diffraction differently from the single clear incandescent desklamp used in these photos.
    And the 50mm f/2 AI Nikkor's IR shift setting was crucial here at close range - without it the first test photos were badly out of focus. The Tamron 24mm f/2.5 Adaptall I'd been using for IR this year is less critical about IR shift, even at fairly close range, and stopping down to f/4-f/5.6 solved most minor focus errors.
    I didn't take notes on the specific filters or polarizer adjustments used. Some combined a pair of stacked conventionally designed circular polarizers, along with the Cokin circular polarizer and Pola Red-Green. Some used the #25A red, some didn't.
    Combining two or more circular polarizers provided some IR effect even when visible light was bright enough through the viewfinder to enable focusing in reasonably bright indoor lighting: a hot electric stovetop element turned white, as did a red "exit" sign (presumably incandescent rather than fluorescent), as well as the various colorful nightlights we have around here - all were rendered white with IR. That opens up some interesting possibilities for odd looking photos in which almost everything appears normally, except for IR-emitting lights.
    Interestingly, the most consistent thing in every variation was the lanyard attachment looped through the eyelet for the wrist strap - the black lanyard loop turned white in every photo, while the black wrist strap itself was consistently black.
  25. this site has a handy lens list of hot-spot 'performance'.
  26. 720nm and other IR filters, in a variety of sizes, are available mail order from China for about $5 each.
    I tried a 720nm filter on the Fuji S602zoom. For one, it has an electronic viewfinder, so you can see what it looks like. I am not sure quite how the internal filter works, but exposure times aren't all that long.
    I haven't tried in on my D70s yet.
  27. From the EXIF data, the above was 1/5s at f/2.8 on a bright, but maybe not sunny, day.
  28. Glen, try the filter on your D70s. You'll get much better results with raw files.
  29. Chip
    One of the challenges of IR is that a lens that works well on one camera may not work as well on another camera. The usual culprit is a hot spot.
    I found if I spent enough time looking through the viewfinder with only an R72 filter on the camera I could start to make out the image.
    And I can tell you that having something like a D200 modified for IR only is so different from using just a filter. Exposure times go way down and you get a boost in resolution as the Bayer filter is removed when the modification is done.
    The links that I posted where to images shot with a modified D200
  30. as the Bayer filter is removed when the modification is done​
    Are you sure that goes? The IR blocker and the AA filter go, but I think the Bayer is permanently bonded onto the sensor surface.
  31. I am not positive. But I remember reading it some place. I will have to look around and see if I can find it again. I can say for sure that I have seen a jump in resolution with my D200 from before the conversion to after the conversion..
    I will get back to you in a bit when I find out for sure.
  32. I tried the D70s with the 720nm filter.
    Oh, I was a little off on the price. The 52mm is $7.26 including shipping. I actually bought the 55mm and a 52-55 step up ring for a few dollars more.
    I can handhold the camera in sun, and even open shade. At ISO 1600 with an AI 35/2.0 at f/2 and 1/20 s, it is about right. (The first Nikon lens I ever bought, 35 years ago.)
    Also, the green focus dot still works, so it isn't so hard to focus, even though you can't see the picture. I will have to try an AF lens.
    I will post some pictures later.
  33. A goose, again cropped to a 700px square out of the D70s image.
    Again, 1/30s at f/2.0 and ISO 1600.
  34. Michael B, I guess the AA filter removal will sharpen things up a bit, but the Bayer's job of colour 'designation' is sensor site or pixel specific, so don't think it comes off!
  35. This thread prompted me to go back and rework some IR photos from the summer. I never did get around to trying the usual red-blue channel mixer swap, so I tried it today. Some of the results were subjectively "better", while other photos lost some of the odd characteristics that makes color IR interesting. I can understand why some folks prefer the red-blue swap for a more familiar blue sky, but it doesn't suit every photo.
    Mushy, more conventional red-blue channel mixer swap. The practice golf balls lost their yellow color, but mushy picked it up in the exchange.
  36. Mike H
    I was confused I found what I had read and it was the AA filter not the Bayer filter that was removed and accounts for the increased sharpness.
    Sorry I really dislike putting misinformation out there
  37. OK, but without the IR block filter, the question is how much IR they Bayer array filters let through. It could be that they all don't block IR, at least for longer wavelengths.
    The band gap of Si is at about 1100nm, though it is indirect gap, which complicates the absorption. So, it might only go to 1000nm, but that is still pretty far. It wouldn't surprise me if all let through 1000nm.

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