Technical knowhow Thoughts on Cameras

The Leica M8 – With or without a infrared cut filter, this is the comparison …

When I posted the first few shots from the Leica M8, I made comment about the colour being a bit whacky inside my living room almost forcing me to shoot black and white. This was caused by my not using an infrared cut filter. A couple of people asked me what I meant by this, so now I have a filter that fits my Sonnar, I thought I’d do a side by side comparison of shots with and without the filter.

The technical bit (dumbed down)

Before I get into this, I just want to point out (like I have many times on this blog) that I’m not particularly technically minded, therefore my descriptions of these things are as I understand them, and perhaps not technically 100% – though in my view, they are all you need to understand to get by.

Near infrared and the Leica M8

When Leica released the M8, I guess they wanted their digital offering to have an edge over the competition in terms of image quality. Unlike today where we have now countless cameras on the market that exclude anti-aliasing filters, back in 2008 they were very much the standard. These filters are part of the construction of the cameras sensor, they make up the front most part of the sensor, and are there (believe it or not) to very slightly soften the image produced. This softening reduces the potential for moire pattern, or in the case of earlier lower resolution sensors, jagged digital-looking edges – hence “anti-aliasing”. What Leica did was to attempt to increase the resolution potential of the 10mp sensor in the M8 by thinning, and therefore reducing the effect of this filter. In some ways this was great, they achieved their goal of sharper photos, but it seems they didn’t count on the increased near-infrared transmittance of the thinned filter.

The problem of near-infrared

The filters on the front of sensors also have the job of limiting the band of wavelengths of light that hits the sensor. To dig around in my brain for some GCSE physics for a moment, visible light is just part of the electromagnetic spectrum. Within this spectrum there are also radio waves, microwaves, gamma rays, X-rays etc. Either side of the visible light part of the spectrum – the part that reflect of surfaces and gives us the colours we see – are ultraviolet and infrared waves. UV and IR aren’t visible to the human eye, but they are – at least to some degree – visible to a camera sensor.

A CCD sensor – as in the M8 – has a bayer filter. This filter is made up of red, green and blue tiny little filters that are sat above the photosites. The photosites are the tiny little light sensitive surfaces that measure the luminosity of the light hitting them. Four of these photosites make up a pixel, two green, one red and one blue. The cameras job is to process the combination of these measured signals and turn it into a coloured pixel in the final image. With me so far? (I’m not sure I am).

Of course, we can’t see near-infrared in the same way we can’t see radio waves or microwaves, and because we can’t see it, it obviously doesn’t have a colour. Because it doesn’t have a colour it doesn’t fit into the colour gamuts we program into our computers to work with. This means that when infrared hits a sensor, it registers a signal in the sensor in the same way as visible light does. The result of this is that this signal gets processed by the camera and fitted erroneously into the colour gamut the camera uses (SRGB or Adobe RGB). It effectively therefore pollutes the signal being processed by the camera resulting in images that suffer with colour shift in the areas where the camera has “seen” the near-infrared light.

Technical bit out of the way, here’s the problem illustrated

Thankfully, even in the Leica M8 where the near-infrared does have an impact, the impact is reasonably subtle in most shooting circumstances. But sometimes it’s impossible to miss, and unfortunately very difficult to process out after the photo has been taken.

I haven’t processed any of these images, other than just matching the white balance between the pairs. Matching the white balance does somewhat increase the difference between the images, but it does illustrate the point, and no amount of tinkering with white balance fixes the problem.

In the first pair, look at the difference in the colour of my dark blue/grey sofa

L9346859

With filter

L9346858

Without filter

In this pair it’s most noticeable in the grey dog bed in the background and the black of Norah’s cow

L9346855

With filter

L9346856

Without filter

Again, the dark blue/grey sofa and grey curtains

L9346849

With filter

L9346850

Without filter

In this shot I’ve tried to demo the effect on foliage which goes much more yellow/pink

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With filter

L9346843

Without filter

And finally, where I have found the biggest issue, in artificial light.

L9346822

With filter

L9346823

Without filter

The solution

As you can imagine, this didn’t go down all to well when Leica brought out the M8. Having done a bit of reading on the subject, it seems they attempted to remedy the issue by offering two free screw on IR/UV lens filters to anyone who had purchased the Leica M8. It is one of those filters I’ve been experimenting with screwed on to the front of my Sonnar. Of course, filters come with their own disadvantages, not least increased potential for flare, and even (if you are picky) a potential reduction in resolution.

I shall of course come back to this when I get to reviewing the Leica M8, so if you are interested in reading my eventual thoughts on the camera, then get yourself subscribed to me email updates below…

Cheers,

Hamish

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26 Comments

  • Reply
    Frank Lehnen
    February 14, 2016 at 11:58 am

    Makes me wonder what the bigwigs at Leica were thinking back then? Just hurry out a rival to the Epson R-D1 as fast as possible, no matter if fully tested or not? Remember, it was Leica who said a digital Rangefinder was not feasible, just months before the release of the R-D1….

    • Reply
      Hamish Gill
      February 14, 2016 at 11:59 am

      Maybe they just don’t have man made fabric in the Leica testing facility? 😉

      • Reply
        Frank Lehnen
        February 14, 2016 at 7:26 pm

        Funny !! I think this wan one of the greatest f..ckups of camera history – at least for a brand like Leica

        • Reply
          Hamish Gill
          February 14, 2016 at 7:30 pm

          Yeah, I can’t think of anything as serious. There have been a few DSLRs – Nikons d600 with its dirty sensor was quite a big balls up I suppose… But not on this scale I don’t think

        • Reply
          Hamish Gill
          February 14, 2016 at 7:30 pm

          Did Leica ever make excuse for it, or did they just hold their hands up, do we know…?

    • Reply
      Hamish Gill
      February 14, 2016 at 11:59 am

      … Or any plants

      • Reply
        Frank Lehnen
        February 14, 2016 at 7:28 pm

        Read the f..ng manual, if you understand german: “Keine Bilder von Pflanzen oder schwarzem Stoff bitte!” ;-))

        • Reply
          Hamish Gill
          February 14, 2016 at 7:36 pm

          … es sei denn, Sie möchten rosa Fotos
          (Person my use of Google translate ;))

  • Reply
    Des McSweeney
    February 14, 2016 at 7:10 pm

    Hi Hamish. You always say you are not “technically minded”, but for those of us who genuinely aren’t that is just the best explanation of how a sensor works (or doesn’t). I have just looked back though my M8 pics and of course you are right the greys ain’t so good and it appears I haven’t actually taken many pics of plants. I have had two M8s (don’t ask) and they didn’t react in exactly the same way either which is even more confusing. All is good in B&W though…

    • Reply
      Hamish Gill
      February 14, 2016 at 7:50 pm

      I’ll never forget my chemistry teacher telling me at the beginning of GCSE chemistry “everything you’ve learned about chemistry so far is oversimplified and technically wrong”. That was the last thing I understood that came out of her mouth for the next 2 years. I’m much more happy with the simple version, it turns out 😉
      It certainly takes a good black and white shot… At least apart from the banding at high ISOs… But that’s a story for the review I think 😉

  • Reply
    KJ Vogelius
    February 14, 2016 at 10:06 pm

    Another reason that Leica made the sensor cover stack so thin is because their sensors need to handle steep ray angles (i.e light rays coming out of a lens at an angle compared to the sensor). Generally this trait is a result from compact lens designs and many of Leica’s lenses exhibit this. This is also why many M-mount lenses exhibit colour shifts and smearing mounted on mirrorless cameras – their cover stacks are thicker, acting as a lens surface. It’s a tricky problem and harder the larger the sensor. So the problem is harder with the M8 compared to the R-D1 for instance. And harder still with the M9 (which is probably why they’ve had issues with cracking and corroding cover glass) as well as the M240. Sorry to go on a bit, but if anyone’s interested in more information about this and some workarounds I’ve written more about this on my site – you can click my name to read the article. Anyway, look forward to the full review Hamish. Thanks!

    • Reply
      Hamish Gill
      February 14, 2016 at 10:11 pm

      Ah, makes sense! I think I’ve read this before actually – there is a company that replaces the Sony A7 filters with thinner ones for similar effect I think …?

  • Reply
    Ned
    February 14, 2016 at 10:49 pm

    The combination of the Sonnar (with filter) and the M8 sensor looks very, very promising.
    The crop factor gives you a nice focal length for portraits.
    Is it heresy to say that an M8/M8.2 is in the back of my mind? Should I return to the dark side, it ticks quite a few boxes.
    Looking forward to your review Hamish.

    • Reply
      Blinx
      February 16, 2016 at 4:00 pm

      I’d look at an X-Pro1 first, Ned. Cheap as chips, nicely built, optical or electronic viewfinders and focus assist for manual lenses. Write speeds are a bit laborious, AF isn’t stellar (though pretty good with latest firmware). I haven’t tried an M8 (in case I like it!) but bet the X-Trans sensor is the superior tool. OTOH the M8 is certain to become a cult camera on weirdness alone, but prices haven’t fallen sufficiently to match weird buyers like myself.

      • Reply
        Elie Bescont
        July 5, 2016 at 11:18 pm

        The M8 is a thousand times better than the X-Pro, only because it’s a Leica M camera and it means it has the Leica M focusing system. Can’t beat that.

        • Reply
          Andre Martell
          March 13, 2017 at 5:32 pm

          The M8 is a limited camera in every way, least of which is its abysmal high ISO performance. In has no versatility or flexibility. If you are lucky you can get one or two of your lenses calibrated enough to work for you and that’s after having sent the camera off for a rangefinder adjustment since it seems to drift all on it’s own.

          I got a used Fuji XE-1 with a Zeiss and Fuji auto-focus lenses, which produces imagines just as good or superior to the M8 at a cost LESS than what it would have been to send my M8 in to have the rangefinder adjusted and my 90mm APO ASPH adjusted because it front focused something fierce on it, however as soon as I mounted it on my XE-1 it was absolutely brilliant.

          So I now have a camera that is small, user friendly, easy to manual focus, takes virtually any 35mm lens ever made via an adapter and has an impressive line of sharp lenses and auto-focuses as well with a built in diopter adjustment.

          I paid a whopping $175 dollars for this camera and I carry it every single day and keep the Zeiss Touit 32 1.8 attached to it because it is excellent and makes shooting effortless. Speaking of effortless my 90mm APO ASPH was unusable on my M8 and my 135mm Elmar was almost impossible to shoot with on my M8 and on this cheap Fuji camera they absolutely sing! The 135mm Elmar f4 is razor sharp on it! The reason the Elmar 135 can be had so cheaply is because they are difficult to shot on a rangefinder and not because they are poor quality Leica lenses.

          And Leica service is horrible and expensive. I know people who have waited 6 months or more to get their issues addressed and quite often they aren’t addresses or come back with new issues.

          I love Leica glass but they can keep all of their digital rangefinders, the famed Leica quality, consistency and durability just isn’t there any longer. They are a overpriced and overhyped boutique brand now.

      • Reply
        Ken Hindle-May
        July 6, 2016 at 10:51 am

        I sold all my Canon digital gear and got a Fuji X-T10 and a couple of lenses, and I’m super happy I did it. I love having physical controls on a digital camera and now I have a very good shooting kit that I can just throw in my messenger bag on the off chance I might want to shoot. With a DSLR, I was either going out to shoot or I wasn’t. No middle ground. I also really like Fuji’s film simulations, which mean I now spend minimal time editing in Lightroom (in fact, I often post straight from my phone while still out after minimal tweaks in Aviary) and it’s so easy to use my old SLR lenses with the Fuji, which was a bit of a nightmare on the Canon EF mount before.

        It’s not perfect – I really struggled to shoot a running race at the weekend because of the limited battery life (exacerbated by the need to use an EVF all the time) and slow AF, but that’s not really what I bought the camera for and it’s perfect for my bread & butter shooting – street, abstract, lifestyle etc.

  • Reply
    Ned
    February 16, 2016 at 7:44 pm

    Thanks for the heads up Blinx.
    As I am currently cameraless, I am working through the options and one possibility of pairing up an M8 and an M film body, sharing lenses, seems (at face value) to be attractive.
    I had an X100s, so I know how good these Fuji’s are.
    I also sold my CL, so plenty for me to think about.
    Cheers

  • Reply
    Francois
    May 1, 2016 at 11:11 pm

    Thanks for your review, it helped me decide to get a used M8 (4000 shots) at a decent market price 1600 CA$ and even with the 1.33 crop factor I find this is a great camera, having leica glass also helps. After about 20 years of leica film use (name it, I tried them) I felt we have reached the Tipping Point regarding film, less films made, much more expensive to purchase and have processed. Of course buying a 10-year old (almost) digital camera may not be the wisest purchase, yet I have no regrets and no buyer’s remorse. I find the experience with the M8 quite similar to the one I had with my other M’s, which is a pleasant, slower way of taking pictures. 10 megapixels and Leica glass are good enough.
    Of course, I would have liked a newer full frame version but prices are just too much for my budget. I also kept a mint Leicaflex SL2 with an Elmarit 35…old habits die hard. So for those who are still thinking of getting into digital M, do it and you might be surprised.

  • Reply
    Elie Bescont
    July 5, 2016 at 11:14 pm

    I use the Leica M8 without any IR filter, exclusively. The issue is easily corrected during post-processing and infrared adds more nuances in dark tones for B&W photography.

    • Reply
      Hamish Gill
      July 7, 2016 at 5:49 am

      Hi Elie – I’d be interested in your process for correction in post. I’ve had some luck, but nothing that I wouldn’t say it also damaging to the colour elsewhere

      • Reply
        Elie Bescont
        July 7, 2016 at 10:57 am

        Sure Hamish.

        The first thing to do is to get the correct tint of the whole image, by moving the tint of the image from 2 to 4 points towards green.

        Then, apply masks on corrupted fabric, apply a big deal of desaturation to them and bring the right color back by adding a color to it.

        Then, move to the TSL section and change the tint of green and yellow a bit so foliage becomes green again.

        And, that’s basically it.

  • Reply
    Brian Sweeney
    August 22, 2016 at 11:59 pm

    Most manufacturers use IR absorbing glass that by itself will corrode in the presence of moisture; they sandwich this glass in between non-corrosive glass. The result is a thick filter stack. This is the problem with the original M9 sensor; an efficient IR absorbing material (S8612 glass, 0.8mm) was used, but it corroded in the presence of moisture. For the M8: Kodak chose IR absorbing glass (0.5mm) that did not corrode in the presence of moisture, but was not as efficient in absorbing IR. It allows a 5% leakage. Use an IR cut filter to get rid of the contamination; OR use an Orange Filter to leave the Blue channel sensitive to IR only; Boost it; get some Infrared-Ektachrome style colors. The M8 used with the IR cut filter will produce a “crisper” image than the M9, a result of the thinner filter stack.

  • Reply
    Tom Niblick
    February 19, 2017 at 5:47 am

    I bought a Leica M8 when it first came out and shot about 10,000 photos with it. The camera was not perfect but I really liked it. Color without the filters was no big deal when shooting landscapes. Filters were needed when photographing people (weddings). I loved the results when shooting B&W. And adding a #93 filter produced wonderful IR effects. It was a good camera overall. And a good choice now if you shoot IR.

  • Reply
    Stillsy
    December 16, 2017 at 7:43 am

    Except for the final teddy bear shot I kinda of prefer the look of the no IR filter image outputs shown here. More than halfway to where I like being with my PP look.

    Horses for courses hey….

  • Reply
    Benson
    June 17, 2018 at 12:08 am

    Call me insane, (I’m quite likely to agree), but I actually preferred some of the images without the filter on.

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