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Infrared and full spectrum photography with m4/3 cameras

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  • Infrared and full spectrum photography with m4/3 cameras

    I've been working on this post for a little while, and the new forum is a good opportunity to post it.

    Several forum members have infrared- and full spectrum-converted m4/3 bodies, but there are few resources focused on m4/3 across the web, and some of the information I have found is not correct, at least by my own experience. It seems a good idea to provide an opportunity to pull together the resources we have plus our collective experience.

    I know that the resulting images can be marmite – I love many of them, but others can’t see the point, and that’s fine by me

    I’m no expert on the technical and practical aspects of sensor conversions or on the filter choices one has to make. Similarly, almost all the information on processing colour or mono images relates to Photoshop and Lightroom, neither of which I use, and so I’m not going to post much at all on PP.

    To save me having to cover them, here are some useful basic and advanced resources from the established and widely-recommended UK and US companies selling IR conversions:

    https://www.protechrepairs.co.uk/
    https://advancedcameraservices.co.uk/products/
    https://kolarivision.com/what-is-infrared-photography/
    https://www.lifepixel.com/introduction

    However, I have now got quite a bit of experience with converting mono 720nm filtered raw images and some colour ones with Capture One Pro, and I get results that satisfy me at least! Maybe I’m just easily pleased, but I’ve discussed this with CO experts, and I’m sure this relates to the particular way CO colour management is implemented. It just seems to suit IR processing, and you don’t need to get involved with ‘channel swapping’ and other witchcraft. After raw conversion, in my experience the Nik suite is brilliant for enhancing detail and tonal contrasts.

    After a brief introduction, I’m going to describe in the rest of this first post which m4/3 lenses I have personally tested for IR use (principally with 720nm filters).
    I hope to add a few more posts, including why I chose the gear I did and why I had it converted to full spectrum by Protech ( https://www.protechrepairs.co.uk/inf...r_choices.html ).

    Modern lenses are super-optimised for handling the wavelengths of the visible spectrum, and as soon as your sensor starts detecting longer wavelengths all sorts of strange things happen. Sophisticated lens coatings may flare badly in IR, nasty colour casts and internal reflections are frequent, and since IR wavelengths may be brought to a different focus from the visible range, soft focus may be inherent especially as you widen the spectrum detected. It’s often said that older lenses with more basic coatings and simpler optical formulae are more reliably usable for IR.

    The commonest problem with many lenses is a central ‘hot spot’ of brighter imaging, often covering the central 30% or so of the frame. Although I’ve never seen this written down, this seems mainly to be a central colour hot spot, and the ones caused by many lenses seem largely to disappear when you do the raw conversion. They are also often amenable to fiddling around with blue sensitivity in the raw converter, and if all else fails, skilled use of radial masking will fix the issue.

    There’s no doubt, however, that avoiding hot spots from the beginning by careful choice of lens is the simplest and quickest solution. Different optics vary enormously in the quality of their images through a 720nm filter, and it’s not predictable. For example, the 40-150 f2.8 Pro zoom is excellent, certainly from f2.8 to 5.6; in contrast, the 12-100 f4 Pro is appalling at all apertures (brown cast, soft, awful hot-spot).

    Hot spots are often only an issue when partially stopped down, and some modern lenses with sophisticated optics are actually very good in my experience at full aperture – the Olympus f1.2 17mm and 45mm Pro primes being cases in point. Stop them down to beyond around f4, however, and they’re hopeless.

    Especially in bright sunlight (when IR light is plentiful, and IR photography comes in to its own) I find my optics quite sensitive to flare, so I always use a lens hood and often give additional shading with my hand. This might be more of an issue for me since I must add a filter to the front of the lens with my full spectrum camera.

    So, here are my results for the m4/3 lenses I’ve tried on my E-M10ii with a full spectrum conversion by Protech and screw-on 720nm filters (a mix of Hoya, B+W and Zomei of different diameters). This is not a scientific study, and is based only on fairly quick and dirty eyeballing of raw files imported to CO.

    If a range of apertures isn’t given for which a lens is described as ‘Good’ I tested it from full aperture as far as f8.0. I tested zooms fully wide, fully tele, and around halfway between – in fact I didn’t spot any significant differences in IR performance for any of them throughout the focal length range with the quick and subjective assessment I used.

    Others’ mileage may well differ with different equipment, and my experience with some lenses certainly differs from some recommendations to be found on the web, maybe for this reason. In this list, ‘Poor’ optics & settings often give usable images after tweaking in post, ‘Awful’ is just that.

    Olympus
    9-18 f4.0-5.6 Good.
    12-100 Awful (brown cast, soft, hot-spot).
    17 f1.2 Good f1.2 to f2.8, awful hot-spot after f4.0.
    40-150 f2.8 Good f2.8 to 5.6, worsening hot-spot after that.
    45 f1.2 Good f1.2 to f2.8, awful hot-spot after f4.0.
    75mm f1.8 Good to f2.8, acceptable to f5.6, worsening hot-spot after that.

    Panasonic
    12-32 f3.5-5.6 Good.
    12-35 f2.8 Good to f4.0, acceptable to f5.6, increasing hot spot after that.
    15 f1.7 Good.
    35-100 f4.0-5.6 Good.

    Laowa
    7.5 f2.0 Awful (soft, brown cast).

    Samyang
    7.5mm f3.5 fisheye Good (I sold this lens before testing it properly, but I tended to leave it at f5.6 permanently, and it was fine at that).

    I have a few more lenses I haven’t yet tried for IR, e.g. the Olympus 8mm f1.8 fisheye, and I’ll update this thread when I have.

    You don’t often just want to carry an IR-converted body (although I do have a high-quality 37mm B+W IR and UV blocking filter, which fits the Panny 12-32 and gives a decent approximation of normal visible light). Hence, I’d say that converting a small body is sensible: several of my camera club members have converted various iterations of the Sony RX100, but adding external filters to that is a pain and I did want a full-spectrum conversion, and the light and compact M10ii fits my needs well.Many people convert a body they've just upgraded, rather than selling it. I bought the M10ii new, but it was on a short-lived and crazy SRS deal for around £230 after various discounts and cashback, which was hard to resist.

    My standard IR setup is just to add the M10ii with the Panny 12-32 to whatever else I’m carrying, but when I know I’m going to have particularly good opportunities for IR work (midday sunshine, lots of trees & plants) I also bring along the 9-18 and 35-100.


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    Regards,
    Mark

    ------------------------------
    http://www.microcontrast.com
    Too much Oly gear.
    Panasonic GM5, 12-32, 12-35, 15, 35-100, Laowa 7.5.
    Assorted legacy lenses, plus a Fuji X70 & a Sony A7S.

  • #2
    Wow Mark, some spectacular results. Something that I personally am not busting to accomplish, but interesting knowledge anyway. Many thanks for sharing and the for the work you have put into it...

    Comment


    • #3
      Thanks for this comprehensive guide and excellent examples.
      John

      "A hundredth of a second here, a hundredth of a second there � even if you put them end to end, they still only add up to one, two, perhaps three seconds, snatched from eternity." ~ Robert Doisneau

      Comment


      • #4
        Well done Mark, I can see this thread becoming very popular. Thanks for all the work you have done.
        Graham

        We often repeat the mistakes we most enjoy...

        Comment


        • #5
          Well, I’d tried out the lenses and thought some people might find the results useful. I’m also hoping to learn from others’ experience.

          i know there are a number of people here with a lot more experience than I, especially of false colour IR photography, which is something I’d like to get in to next year.
          Regards,
          Mark

          ------------------------------
          http://www.microcontrast.com
          Too much Oly gear.
          Panasonic GM5, 12-32, 12-35, 15, 35-100, Laowa 7.5.
          Assorted legacy lenses, plus a Fuji X70 & a Sony A7S.

          Comment


          • #6
            I must get my IR converter E-PL1 out - i did notice a number of lenses had hot-spots.

            Ian
            Founder and editor of:
            Olympus UK E-System User Group (http://e-group.uk.net)
            Four Thirds User (http://fourthirds-user.com)
            Digital Photography Now (http://dpnow.com)
            Olympus camera, lens, and accessory hire (http://e-group.uk.net/hire)

            Twitter: www.twitter.com/ian_burley
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            sigpic

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            • #7
              Originally posted by Ian View Post
              I must get my IR converter E-PL1 out - i did notice a number of lenses had hot-spots.

              Ian
              Yes, I don't now have any of the Olympus kit lenses, which are mostly said to have good IR performance, so I can't test them. I've never had a 12-40 f2.8.

              Ones said to be good are the various versions of the 14-42 and the 12-50, but I haven't seen any reports on the various 40-150-ish tele zooms or the 14-150. It would also be interesting to know how things like the 12 f2 and 17, 25 and 45 f1.8 perform.
              Regards,
              Mark

              ------------------------------
              http://www.microcontrast.com
              Too much Oly gear.
              Panasonic GM5, 12-32, 12-35, 15, 35-100, Laowa 7.5.
              Assorted legacy lenses, plus a Fuji X70 & a Sony A7S.

              Comment


              • #8
                Thank you Mark.
                Cameras: E-M5, E-PM2, OM40, OM4Ti
                Lenses (M.Zuiko Digital): 7-14mm/F2.8, 12-40mm/F2.8, 40-150mm/F2.8+TC1.4x, 12-50mm/F3.5-6.3, 14-42mm/F3.5-5.6 EZ, M.ZD 40-150 F4-5.6 R, 75-300mm/F4.8-6.7 Mk1, 12mm/F2, 17mm/F1.8
                Lenses (OM Zuiko): 50mm/F1.2, 24mm/F2, 35mm/F2.8 shift
                Lenses (OM Fit): Vivitar Series II 28-105mm/F2.8-3.8, Sigma 21-35mm/F3.4-4.2, Sigma 35-70mm/F2.8-4, Sigma 75-200mm/F2.8-3.5, Vivitar Series II 100-500mm/F5.6-8.0, Centon 500mm/F8 Mirror
                Learn something new every day

                Comment


                • #9
                  To add to your list of native MFT lenses for IR.
                  Native lenses tried:
                  Panasonic 14-42 (see below)
                  Panasonic 45-200 (see below)
                  Olympus 17mm /2.8 pancake - not hot spots very useful for trying smaller filters such as 25mm unmounted technical glass.
                  Samyang 300mm mirror - barely used for IR but no issues yet.
                  Olympus 9mm BCL -no issues yet (it's difficult to mount filters but they can be held in front of the lens - a cokin mounting ring makes a convenient handle)
                  No name 8mm/3.8 fisheye -no issues yet (it's difficult to mount filters but they can be held in front of the lens if the hood doesn't get in the way the edges of the FOV often go round the filter)

                  I've not seen hotspots from any of my native mount lenses on my converted body but the IR transmission of both my Panasonic lenses seems significantly down on what I would consider normal. When I tried the 14-42 on a standard body for long exposure IR I did get severe hotspots. The 45-200 has been OK on this test giving some fairly long exposures of the London eye from Buckingham palace, without issues.

                  Most of my shots with the converted camera have been false colour IR, usually via a 25A filter, but also using Wratten #47, BG3, U330 and a selection of old photographic filters.

                  Mike
                  Compulsive photographic Dabbler.
                  Flickr

                  Comment


                  • #10
                    Originally posted by drmarkf View Post

                    Yes, I don't now have any of the Olympus kit lenses, which are mostly said to have good IR performance, so I can't test them. I've never had a 12-40 f2.8.

                    Ones said to be good are the various versions of the 14-42 and the 12-50, but I haven't seen any reports on the various 40-150-ish tele zooms or the 14-150. It would also be interesting to know how things like the 12 f2 and 17, 25 and 45 f1.8 perform.
                    I’ve got a couple of the lenses you haven’t if you’d like to test them? Pop over if you fancy?
                    Paul

                    I didn’t get where I am today....

                    Comment


                    • #11
                      Originally posted by Walti View Post

                      I’ve got a couple of the lenses you haven’t if you’d like to test them? Pop over if you fancy?
                      Great idea, thanks Paul.
                      I could take the opportunity also to test a couple of my lenses that I haven’t yet tried.

                      Im currently v busy catching up after returning home from a 3-week holiday, so as soon as that’s sorted I’ll drop you a PM. Probably best to choose a sunny day, and maybe we could go somewhere nearby with some greenery (ie grass & conifers at this time of year ).
                      Regards,
                      Mark

                      ------------------------------
                      http://www.microcontrast.com
                      Too much Oly gear.
                      Panasonic GM5, 12-32, 12-35, 15, 35-100, Laowa 7.5.
                      Assorted legacy lenses, plus a Fuji X70 & a Sony A7S.

                      Comment


                      • #12
                        I have tried the IR using a IR filter. As with a filter, it's long exposure. So that brings me to the first question, in a converted camera, there is no turning back. Yes? But unlike a filter, can you still see images through the EVF? Exposure, the same rules applies like Full matrix, Center weighted and Spot or is it full manual?

                        Processing, Back then when I was using the IR filter, everything was in RED. Do you shoot in B&W then? What's the post processing like? Is it from post processing if I want a sky like that of the Lifepixel.com (the 4th link).
                        * Henry
                        * Location: Subang Jaya, Selangor
                        * Malaysia


                        All my garbage so far.

                        Comment


                        • #13
                          Originally posted by blu-by-u View Post
                          I have tried the IR using a IR filter. As with a filter, it's long exposure. So that brings me to the first question, in a converted camera, there is no turning back. Yes? But unlike a filter, can you still see images through the EVF? Exposure, the same rules applies like Full matrix, Center weighted and Spot or is it full manual?

                          Processing, Back then when I was using the IR filter, everything was in RED. Do you shoot in B&W then? What's the post processing like? Is it from post processing if I want a sky like that of the Lifepixel.com (the 4th link).
                          Not quite. With a full spectrum conversion there is a fair degree of 'turning back' as the sensor sees visible, IR & UV. You can fit a IR/UV blocking filter in front of the lens, and get visible only. The white balance might need adjusting if the filter you use doesn't closely match the original one..

                          With an EVF the viewfinder will show what the sensor sees. Either before or after conversion this will include any IR seen. I've never heard of a converted camera loosing any metering options. With the exception of dust removal (often lost during conversion) the camera should function as before except it will now see different wavelengths.

                          The usual procedure is to employ a custom white balance, which can deal with the red cast you've seen. If using a filter /conversion longer than 720nm it's unlikely you'll get any usable colour information, so desaturating is the usual approach for these (and also used for many other filter types where a monochrome image is wanted).

                          With more permissive long pass conversions there are several approaches to getting a blue sky - a red/blue channel swap is generally the most common, but I tend to use hue adjustment (~180°) or sometimes just negative conversion.

                          There are a few conversions that make the camera sensitive to blue (&/or UV) & IR without the visual greens & reds. These give IR in all three channels but still get visual blue in the skies straight out of the camera. On my full spectrum camera, I've had results along these lines with Wratten #47, BG3, & U330 filters.
                          Mike
                          Compulsive photographic Dabbler.
                          Flickr

                          Comment


                          • #14
                            Originally posted by Petrochemist View Post

                            Not quite. With a full spectrum conversion there is a fair degree of 'turning back' as the sensor sees visible, IR & UV. You can fit a IR/UV blocking filter in front of the lens, and get visible only. The white balance might need adjusting if the filter you use doesn't closely match the original one..

                            With an EVF the viewfinder will show what the sensor sees. Either before or after conversion this will include any IR seen. I've never heard of a converted camera loosing any metering options. With the exception of dust removal (often lost during conversion) the camera should function as before except it will now see different wavelengths.

                            The usual procedure is to employ a custom white balance, which can deal with the red cast you've seen. If using a filter /conversion longer than 720nm it's unlikely you'll get any usable colour information, so desaturating is the usual approach for these (and also used for many other filter types where a monochrome image is wanted).

                            With more permissive long pass conversions there are several approaches to getting a blue sky - a red/blue channel swap is generally the most common, but I tend to use hue adjustment (~180°) or sometimes just negative conversion.

                            There are a few conversions that make the camera sensitive to blue (&/or UV) & IR without the visual greens & reds. These give IR in all three channels but still get visual blue in the skies straight out of the camera. On my full spectrum camera, I've had results along these lines with Wratten #47, BG3, & U330 filters.
                            Yes, I agree. I'm not sure about dust removal, actually.

                            I generally meter full-screen evaluative, and adjust it via the histogram (which should work reasonably reliably for most cameras if they are set for 'flat' jpegs, although I suspect my M10ii slightly under-reads for some reason I haven't yet fathomed. Consequently I allow some headroom when ETTR-ing).

                            I have 3 custom white balances currently set on my full-spectrum M10ii: to suit 720nm, 850nm, and a Kolari Vision 'Autochrome' filter that I recently acquired.

                            I have a 37mm B+W IR- and UV-cutting filter that fits the 12-32 zoom and gives a very good approximation to a 'normal' spectrum and auto white balance, although I haven't used this beyond a quick test so far.
                            Regards,
                            Mark

                            ------------------------------
                            http://www.microcontrast.com
                            Too much Oly gear.
                            Panasonic GM5, 12-32, 12-35, 15, 35-100, Laowa 7.5.
                            Assorted legacy lenses, plus a Fuji X70 & a Sony A7S.

                            Comment


                            • #15
                              Nice photos but IR is not for me!
                              David

                              EM1ii, EM10ii

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