6-bit coding and other arcana.

For an index of all Leica-related articles click here.

In Part I I recounted the not always happy history of Leica’s digital M camera designs.

In this piece I address 6-bit coding for non-Leica branded lenses, proper rangefinder alignment and sundry other bits and bobs of interest to current and prospective owners of this fine camera. There’s some pretty heavy sailing in what follows but for the most part these are ‘one off’ fixes and the migraine will pass.

6-bit coding: There are good reasons to add 6-bit coding to lenses without it. First, when the camera ‘sees’ the code on the lens’s mount (think of it as a simple variation of the ubiquitous bar code) its software will correct for geometric distortion. More importantly it will correct for color fringing with wider lenses near the edges of the frame, caused by the oblique angle at which light rays are striking the sensor. And for those who use EXIF data as a cataloging and retrieval aid, coding adds the lens name, focal length and aperture used, all missing with uncoded lenses. You can do all of this in Lightroom, of course, where the lens correction profile can correct geometric distortion and LR’s (not very good) chromatic aberration correction function can sort of correct for color fringing. And you can laboriously add EXIF data manually. For me time spent processing is time wasted and I would rather have the camera do all these things.

All the digital Leica models have ‘6-bit’ lens coding which adjusts the output from the various pixels based on the angle of incidence of the light rays. The closer the rear element of the lens is to the sensor the more obliquely will light rays strike the periphery of that sensor. This causes potential color casts, so it’s important to correct for this effect to maintain the lens’s performance at its best. Leica does this using code via colored pits on the mounting flange of the lens known as the ‘6-bit code’. There’s an aftermarket in cheap adapters that you can code with a Uni Ball pen and the databases are out there for all sorts of makes, including Zeiss, Voigtländer/Cosina, Russkie garbage …. but not old LTM Canons! ‘Experts’ claim that coding makes little difference with focal lengths of 50mm and up when it comes to correction of optical aberrations, but is increasingly important as lenses get wider. I find this claim to be bunk. See my results with the 50mm f/1.4 Canon LTM, below.

The design of the microlenses on the sensor differs from the normal approach, as is illustrated in this schematic from the manufacturer CMOSIS:

Microlens design comparisons – Leica below.

The shape is distinctly stretched upwards to better capture light rays striking the lenses at oblique angles, and the photodiodes are closer to the lenses. Ingenious.

DSLR lenses do not suffer from this problem as the clearance required for their flapping mirrors dictates lens designs with greater clearance between the rear element and the sensors, so less oblique peripheral light rays strike the sensor. On the other hand it’s common for users to adapt M lenses to their mirrorless digital bodies and as these do not include the 6-bit/software correction of the Leica sensor I have to wonder how much of the blame for coma and chromatic aberration results from those optics’ rear elements’ close positioning to the sensor.

Below I explain how I upgraded my two Leica Thread Mount Canons, the 35/2 and 50/1.4, after experimenting with the various code/lens choices in the M10:

The 6-bit version of the Fotodiox LTM-to-M adapter.
You fill in the appropriate pits per this table, from the Fred Miranda site.

A ‘1’ indicates black ink filling; a ‘0’ means do nothing. The codes read clockwise as you look at the back of the lens. For example, for the Summilux-M 35mm f/1.4 ASPH the most counterclockwise pit would be blank, the second would be black, the third black, and so on. Refer to the image of my 90mm Tele-Elmarit below for greater clarity. Here are the codes for 35mm and 50mm Leica lenses:

Lens type: Leica item number: 6-bit code

35mm lenses:

Summilux-M 35mm f/1.4 steel rim (re) : 11300, 11301 (chrome) : 001100
Summilux-M 35mm f/1.4 ASPH : 11874, 11883 (chrome) : 011101
Summicron-M 35mm f/2 (IV) : 11310, 11311 (chrome) : 000110
APO-Summicron-M 35mm f/2 ASPH : 11699 : 001101
Summicron-M 35mm f/2 ASPH : 11879, 11882 (chrome) : 01111
Summarit-M 35mm f/2.4 : 11671 : 010001
Summarit-M 35mm f/2.5 : 11643 : 101011

Five of these appear in the manual choices in my M10 which you can dial in if your lens is not coded.

50mm lenses:

Noctilux-M 50mm f/0.95 ASPH : 11602 , 11612 (titan), 11667 (chr : 110001
Noctilux-M 50mm f/1 : 11821, 11822 : 011111
Noctilux-M 50mm f/1.2 ASPH (re) : 11686 : 001110
Summilux-M 50mm f/1.4 (II) : 11868, 11856 (chrome) : 000101
Summilux-M 50mm f/1.4 ASPH (I) : 11891, 11892 (chrome) : 100000
Summilux-M 50mm f/1.4 ASPH (II) : 11728, 11729 (chrome) :
Summicron-M 50mm f/2 (III) : 11817 : 010111
Summicron-M 50mm f/2 (IV) : 11819, 11816 (chrome) : 100001
Summicron-M 50mm f/2 (V) : 11826, 11825 (chrome) : 100001
APO-Summicron-M 50mm f/2 ASPH : 11141, 11811 (black chrome) : 101001
Summarit-M 50mm f/2.4 : 11680, 11681 (chrome) :
Summarit-M 50mm f/2.5 : 11644 : 101100
Elmar-M 50mm f/2.8 : 11831, 11824, 11823 (chrome) : 100010

Eight of these appear in the manual choices in my M10 which you can dial in if your lens is not coded.

Sometime in its life my Tele-Elmarit was retrofitted with a coded mount. You can find replacement bayonet mounts on eBay for $50. When mounted on the camera the 6 pits align with an optical reader in the camera’s bayonet mount, (present in every digital M body), telling the camera’s software how to process the image. Simple and elegant and with 6 binary choices you can program profiles for 64 (2 raised to the 6th power) different pixel responses. Here’s my T-E:

The ‘000100’ pattern is correct for the 90mm Tele-Elmarit.
The white paint fillings are unnecessary.

Adding 6-bit codes to lenses: Shiny ink pens like the Sharpie do not work properly. No need to paint in white ink for blank divot locations, though Leica does this. The recommended pen is the Uni Ball whose ink dries semi-matte.

Why do I need to experiment with various coding schemes? Because, for the life of me, I cannot find the right codes for my 35 and 50mm Canon LTM lenses and the coding table lists no fewer than 10 and 13 coding schemes, respectively, for Leica’s various 35 and 50mm lenses. In each case one of those schemes will yield the best results so I’m going to have to experiment. The first approach will be to dial in the various lens settings sequentially using the LCD option for uncoded lenses, determine the best result after pixel peeping in LRc, then confer that coding using the Uni Ball on my 6-bit Fotodiox versions for a permanent fix. A pair of 6-bit adapters from this maker ran me $51.60 and fit perfectly. In fact they are a smoother fit than the plain ones I originally installed, which ran me $36 for the pair. All display the correct frames in the viewfinder.

Automating import in Lightroom:. Click here to learn how to automatically apply lens profile correction on import of files into Lightroom.

Removing an LTM-to-M adapter: It is extremely poor practice to do this using the bayonet mount on the camera’s body as a resistance tool, unlocking the lens then torquing counter-clockwise against the stop. Especially if the adapter is stuck – it has been known to happen – you are risking changing the precise positioning of the flange or worse. I use a metal aftermarket lens cap, far more robust than Leica’s plastic version, inserting the lens with adapter and twisting CCW. At $15 I would rather destroy the cap than my camera. That cap also has the three raised nubbins on the rear which act as a wrench should your adapter get stuck on the camera. The nubbins fit in the cutouts in the LTM-to-M adapter. You can see that metal rear cap in the image below.

What makes the discovery process of the best code easy is that the M10 has two approaches to recognizing lenses. If the lens is coded then the camera will automatically read those codes, with no override permitted. If it is uncoded you can dial in the lens’s focal length and type manually and that will be used in the absence of the coding pits. This means that, with an uncoded lens, it’s easy to experiment trying any number of variations to see which is best. In addition to correcting for aberrations and vignetting, the use of the correct 6-bit code – whether coded or input manually – ensures that the focal length of the lens is recorded in the EXIF data for an image.

Manual lens input is unreliable: The implementation of manual lens input is flawed in the M10. You mount an uncoded lens and sometimes the camera says no lens is fitted. Then when you do get rid of that message (try again!) and dial in a lens, sometimes that setting ‘takes’ and sometimes it’s disregarded, at random. You can see if the lens has been ‘recognized’ by looking at the Lens Detection menu where focal length/maximum aperture should be displayed. If they are not, try again. And if you think the camera remembers the lens when you have alternated with a coded one, think again. Once an uncoded lens is removed the camera switches back to auto lens recognition and has no memory of which uncoded lens was last fitted. Not great. To experiment, I found it best to use live view where the lens dialed in is clearly disclosed. If it says ‘no lens’, try again. Simply stated, Leica wants you to pay up for coded lenses. Not nice. Last I heard they still offer a service where you send in your lens and they add the code for you. No, you do not want to know the cost, or the turnaround time.

The coding process is simple. I selected a blank sky as my photo target and made sure to include a tree branch in one corner. The evenly illuminated sky will disclose vignetting while the tree branch will immediately reveal color fringing. I then took a picture with each of the 35mm Leica lens choices input in turn, loaded the images into LRc with no corrections applied and scrolled through the images looking for vignetting and color fringing. All images were taken at the lens’s maximum aperture where vignetting is always greatest, regardless of manufacturer. The differences were subtle but they were there, and I chose the best for coding the adapter. This happened to be the 35mm f/2 Summicron v4, pre-ASPH:

Coding the Canon 35mm f/2 Canon LTM:

Making the decision.

The correct coding for that lens is 000110 where ‘1’ indicates a black paint filled pit, ‘0’ means leave as is:

The adapter has been coded – 000110. This is the 35/135 version of the adapter.

The lens is now properly reported as to focal length in LRc. I simply change the name to ‘Canon 35mm LTM’ using the EXIF tool.

As reported in Lightroom.

Coding the Canon 50mm f/1.4 Canon LTM:

Making the decision. The Fotodiox adapter has been coded 000101.
Original plain adapter and tough metal rear lens cap at lower left.

Choosing the best code. Canon 50mm f/1.4 LTM at f/1.4 in all images.
All eight available 50mm choices in the Lens Detection menu shown, from fastest to slowest.

So much for the “experts'” claims that coding lenses 50mm and longer is not required. The highlighted choice clearly has the least vignetting. This excellent Canon 50mm f/1.4 LTM lens has negligible color fringing in any image, just as with the 35mm f/2 Canon, above.

The correct coding for that lens is 000101 where ‘1’ indicates a black paint filled pit, ‘0’ means leave as is, which is the code for the Summilux-M 50/1.4 non-ASPH.

The lens is now properly reported as to focal length in LRc. I simply change the name to ‘Canon 50mm LTM’ after import, using the EXIF tool.

As reported in Lightroom.

Use with the 35mm f/3.5 Summaron RF: While the ‘goggled’ Summaron was designed for the M3, it can also be used with the M2 and later film bodies. The finder magnification drops but framing and focusing on the film bodies are accurate. That combination makes little sense, however, as the M2 et al have native 35mm frame lines dispensing with the need for a bulky goggled lens while showing a larger image. With the digital Leicas things got worse. While they preserve the 27.75mm flange-to-film/sensor distance of their film forbears the flange/sensor assembly has been pushed forward, protruding further from the body. Leica claims this makes the goggles useless for accurate focusing as they are too remote from the digital M’s body, but I have not found this to be the case. I get identical focus settings at 3 feet, 12 feet and infinity. The only thing wrong is that on the M10 the Summaron RF displays the 50/75mm frame lines instead of the 35/90 pair. You can see accurate framing using the frame selector lever but that makes for a rather inconvenient package. But the RF lens focuses accurately and is perfectly usable. Given that the lens was first sold in the 1950s that’s some serious backward compatibility.

The 35mm f/3.5 Summaron RF on the M10.

Other incompatible lenses: None of these can be used – the Zeiss Hologon 15mm f/8 which protrudes too far into the body (these are rarer than honest politicians and not especially good by modern standards), the Type II 50mm Summicron DR where the focusing mechanics interfere (this is the one which takes goggles for close-ups under 3 feet), any collapsible lens which would destroy the shutter mechanism if retracted and 1961-95 Leitz Canada versions of the 35mm Summilux-M f/1.4 which can be attached but will not focus to infinity. Leica can fix that and your wallet simultaneously.

The Zeiss 15mm f/8 3-element Hologon.
Great in its day, now a collectible surpassed by later designs.

ISO setting:. There are two ways of setting ISO on the M10. One is with the lift-and-turn dial in place of the film rewind knob on the film bodies. That’s a beautiful reinterpretation of a classic design – look how ugly the flat top plates of digital predecessors of the M10 are without it. That knob covers a range from 100-6400, plus Auto and Manual. With Auto the camera selects the ISO and as the sensor is known to be largely noise free up to 6400 I leave it set on Auto. You can limit the Auto ISO range using the LCD display. The other way is to set that knob to Manual and set the ISO using the rear LCD. In that case speeds up to ISO 50,000 are available. Given that I got by with 400 ASA Tri-X for decades I doubt I will be going there. Meanwhile, the simple ergonomic design of the external ISO setting knob is a masterstroke and a significant improvement on the screen-only method found in the M10’s predecessors. Leica have made it difficult to pull out the knob to make changes so there’s no way you’re going to make a change accidentally. That’s good design.

By the way, I have the M setting on the ISO knob set to 12,500 using the LCD. That way, if I want a speed faster than 6400 I simply dial that knob to M. The setting is not volatile.

Viewfinder frame illumination and frame pairs: There is no middle finder illumination window between the finder and rangefinder patch windows as seen on the film bodies. Rather than using ambient light to illuminate the finder frames the M10 uses LEDs, and the result is a brighter set of frames in poor light. Frustratingly Leica has stuck with the ‘two frames at a time’ approach where frame pairs for 28/90, 35/135 and 50/75mm are displayed at the same time. For me the perfect Leica M viewfinder was found in the M2 with just three frames – 35, 50 and 90mm – and only one of these visible at a time. No clutter. Plus I’m not about to use a 28, 75 or 135 lens. The 28mm is neither here nor there, with the next usefully wider step being 21mm. The 75mm is a solution looking for a problem. And as Leica itself states in their instruction manual, the 135mm cannot be reliably focused using the rangefinder (though magnified live view is fine) unless stopped down at least two stops. Really. Then why include the frame? I’ll bet that a skilled serviceman can reprogram the frame display and should the camera have to go in for servicing I’ll see if the 35/50/90mm combination of the M2 can be restored. Leica has retained the frame selector lever which allows the user to preview framing regardless of the lens fitted. Nice, and I occasionally use it to preview framing with a different focal length. I already own 35, 50 and 90mm M bayonet optics but might add a 21mm later. In that case live view or a clip on finder may be called for.

Rangefinder patch: The notches to allow estimation of depth of field, based on image overlap, at f/5.6 and f/16, seen in the M film cameras, are gone. I always thought this added unnecessary noise to the finder, and they are not missed.

Geo-tagging: The M10 has no GPS antenna so does not geotag images. One option is to use the Visoflex 2 clip on electronic finder which includes a GPS antenna but rather than use this clunky accessory I prefer to record my walkabout locations using an iPhone and then import locations in Lightroom to geotag the images. Easy and fast, with no bulk and weight added.

Exposure metering method: I only use the optical viewfinder and this means that the sole option for exposure metering is center weighted, which is fine. If you want spot or matrix you have to use live view (rear LCD) which is not something I care to do. I simply do not use the rear LCD for anything other than set up or for checking remaining battery life. I only use the optical viewfinder when taking pictures. The magnificent optical finder is why you pay for a Leica rangefinder camera in the first place. Again, sticking with its minimalist design philosophy, Leica has got it right here.

Super long exposure times: The mechanical dial on the top plate permits exposure times up to 8 seconds. For longer times up to 4 minutes (!) set the dial to ‘B’, activate the camera and depress the button on the front where the film rewind lever used to be on the film bodies. Not exactly intuitive. The LCD will display choices (they vary with ISO) which can be dialed in with the thumbwheel.

The ‘T’ shutter setting: With the shutter speed dial set to ‘B’ the shutter remains open as long as the shutter release is depressed. However if you activate the self-timer with the ‘B’ setting the shutter stays open without finger (or cable release) pressure on the shutter release button. A second pressure on the shutter release button concludes the exposure. Pretty obscure, I know, but handy for long tripod-mounted exposures when you do not have a locking cable release to hand. When the self timer is running a very bright red LED flashes, at the top of the viewfinder window of all places.

Rangefinder adjustment:. There are two easily accessible adjusters for the Leica M rangefinder, film or digital. If your camera suffers a severe blow it’s possible that the vertical alignment of the images will be sub-optimal. Even when in focus the image in the rangefinder patch will be ‘seeing double’. You have to remove the red Leica or Leitz sticker (it’s held with double sided sticky tape) or a screw (M2/M3/M4 models) to access this adjuster which looks like this:

The surprisingly crudely finished vertical rangefinder adjustment screw.

The other more commonly used adjuster is the one for the cam roller which contacts the cam on the rear of the lens. This is used to adjust focus accuracy. It’s eccentrically mounted so turning the retaining screw (or Allen bolt in digital Ms) varies the position of the roller relative to the cam on the lens.

You do this using a 2mm Allen wrench on the M10, with the camera upside down, thus:

The focus accuracy adjustment in progress.

In this position clockwise rotation (toward you) is fine as the stop on the cam roller assembly will prevent motion of the assembly. The screw is tight by design. If rotating counterclockwise (away from you) you want to insert a finger behind the roller to prevent the assembly moving away from you as you turn the wrench.

Why do this? Well, first conduct a critical test, using the longest/fastest lens you have, taking a picture of your test target at the closest focusing distance. For me that’s the 90mm Tele-Elmarit at f/2.8 and 1 meter. It took me six tries to get this dead right and in aggregate I estimate that the total range of motion of the Allen wrench was 10 degrees (out of 360 degrees in a circle). That’s very little. This is a very sensitive adjustment, so take it easy, a bit at a time.

The difference? How about ‘night and day’? And don’t waste time doing this using a test target at infinity – in both the ‘before’ and ‘after’ instances the infinity focus appeared perfect. The sensitivity of the rangefinder is greatest at close distances. I can only wonder how many photographers blame their lens when the problem is solved with this simple adjustment.

Before and after.

Now the camera – and its owner – are ready to go to work.

What about that film Leica M3? The M3? Well, it’s reverting to its originally contemplated status as a display piece among the greatest classic cameras in my home theater. Film really is awful. There it will join a Zeiss Contax IIa – the camera that pointed the way for the Leica M, a Nikon F – the greatest film SLR ever, a Minox B spy camera – a piece which defines the Cold War, a huge Calumet 4×5 Monorail – loved by Hollywood’s glamor photographers, a Paillard Bolex H16 – where Spielberg cut his teeth, and a Rolleiflex 2.8D – a favorite of many ’50s fashion mavens. No chintzing here! Only the best of the best.

In Part III I will take the M10 out for its first field test.

A troubled history leads to a fine camera.

For an index of all Leica-related articles click here.

I bought a used Leica M10 the other day. What follows details how I got there.

Just arrived.

Leica’s understanding of the digital landscape was tortuous and error prone to state it mildly.

Leica M digital history: Their first effort, the Leica M8 in 2006, very late to market, used a Kodak (!) 10mp sensor and was a miscue, as it used a cropped sensor. For goodness’ sake, one of the prime reasons to use a Leica is the 35mm lens. Suddenly it was 50mm because of the crop. And your exotic 21mm became a mundane 28mm. As with all digital Ms the shutter is now metal and vertically running. The body is 14% thicker than that of the film Leica. In its defense I suppose the M8 did force Leica into learning how to make a digital camera with the M8. It just was not a very appealing one. To add insult to injury Kodak got the specs for the sensor’s cover glass wrong resulting in Leica having to offer free IR filters to owners to try and reduce poor rendering of dark fabrics. And that’s before mentioning the maximum ISO of 640 (seriously) and random lock-ups like a Windows computer of yore. A hot mess.

Then came the Leica M9 which was their first full frame sensor effort. But someone at Leica chose a manufacturer seemingly clueless about sensor engineering (yup, Kodak again) and after a while their sensors developed corrosion, rendering the camera useless. And, of course, there are no spares.

Corroded sensor in an M9.

There’s a repair shop which fits aftermarket sensors …. for $2,500. The technical information regarding the causes of corrosion is very well written on that site and recommended to all Leica M9 owners. Now that’s what I call a repair bill. Both the M8 and M9 used CCD sensors whose colors I love (my APS-C Nikon D2x used one), but the trade off is grain and a lower dynamic range compared with CMOS designs. The M9’s CCD sensor had 18mp. Nice, but the shutters in the M8 and M9 were Nikon DSLR noisy and the garish large ‘M9’ script on the front of the top plate just added embarrassment to loudness, the latter courtesy of that red dot. Surprisingly aftermarket replacement batteries are listed by Amazon.

It gets worse. Much worse. The next effort was the strangely named Leica M240 which now exceeded the size of the lovely film M body because another dope at Leica decided to add video. This porker was no less than 25% thicker than the film cameras. The sensor was designed by a Belgian company named CMOSIS and made by STMicroelectronics in Grenoble. Video in a street snapper. Uh huh. But that’s far from the worst of it. You see the aftermarket never made batteries for the camera as the market was too small to justify the tooling costs and, yup, you guessed it. Leica no longer makes the battery, so every M240 will soon be an $8,000 paperweight.

The M240 $8,000 paperweight. Fat and useless.

No, you will not find it on Amazon and Hung So Low sure as heck is not making it. It was Leica’s first effort with a CMOS sensor and had no corrosion issues. M240s can be had for under $3,000 but once the dire battery situation gets recognized they will quickly fall to zero. Worthless. If there was one really good technology development in the M240 it was Leica’s inspired crafting of a series of conical micro lenses to address and correct color fringing issues with wide angle lenses. Now that was genius indeed.

Finally the Leica M10 came along in 2017, priced at $8,995. The sensor was made by the same Belgian company as for the M240. The shutter was now reasonably quiet, like on the M3 of 1954. 24mp, a battery which is still made, no useless video, and the size was almost back to that of the M3. The heights are now identical but the M10 is still 16% (5.5mm) thicker. The button count was reduced and someone is cleaning up selling replacement stick-on logos to cover that ridiculous red dot which screams ’steal me now’. There are two things to dislike about that unnecessary red decoration. First, it screams nouveau riche when all the self effacing street snapper wants is oldveau pauvre. Second, it loudly announces ‘Steal Me Now’. The shortest shutter speed is 1/4000th and there is no electronic shutter. I bought a replacement for the red logo from AGS Supply. It looks like the screw on the M10-P but is actually retained with two-sided sticky tape, just like the red dot. Silly expensive but the alternative of a piece of tape would be an insult to the gorgeous body. The M10 is now discontinued.

The silver tape covering the garish red logo will have to do for now.
The guiding design ethos of the Bauhaus remains, first seen in the 1954 M3.

One interesting variant was the M10-D which deletes the rear LCD, harkening back to film days. I would much prefer this over the stock version, but do you really expect me to pay $2,000 more for less? The M10 was the first digital M that spoke to me on paper, but it required too much paper to buy. I decided to wait, knowing that digital devices lose value faster than a newly minted politician loses his integrity.

With the Leica M11, introduced in January, 2022, also at $8,995, Leica finally knocked it out of the park with a 60mp sensor, switchable to lower settings of 36mp or 18mp. The added sensor Back Side Illumination saw the already good dynamic range of the M10 grow by almost 2 stops. But who needs 60mp? And at almost $10,000 now without a lens you need a really good spell in the market not to feel the pain. Or wait three years for used prices to halve, like with the M10. It’s unclear who makes the sensor for the M11 but given that Sony invented BSI technology it may well be the Japanese company. The M11 offers a silent electronic shutter option for the first time. Nice. That I would like to have in the M10. There’s also 64gB of internal storage so you do not even need SD card and that 64mB will store at least 2,000 DNG/RAW files. Phew! But, then again, a 64gB SDXC card costs all of $15 so if you are buying the M11 for its internal storage a prior visit to your shrink is probably advised. It’s a current model so wait three years after it’s discontinued to snap one up at 50 cents on the dollar.

Well, here’s hoping that they keep making batteries for ‘my’ M10, even if they are ridiculously priced. The user’s manual states that batteries are only good for a scant 4 years.

Cost: But the elephant in the room is the cost of a good used M10. Even 5 years after it was discontinued it’s still silly expensive. A good user film M2/M3/M4 can be had for $1,600 so the M10 is almost thrice as much. You will not find one for less than $4,500. The way I rationalized this outlay was simple. It’s equivalent to 110 rolls of processed and scanned film. Film is as ridiculously expensive as the modern digital M. 110 rolls is not a lot. Mine came from an authorized Leica dealer with a 12 month warranty and a spare battery. Nice, as the M10 is reputed to be something of a battery hog.

One snag is that when it comes time to sell the M10 for something newer, it will have significantly depreciated from today’s cost whereas the film M bodies, if history is any guide, will continue to keep pace with inflation. That’s a sad fact of throwaway digital technology. At some point in the future there will be no key replacement parts for the M10 just as there are no batteries for the M240.

Why did I upgrade from film after returning to the Leica M3 after a 20 year absence from the brand? Well after running a few rolls of Kodak Ektar through it two things became clear. Large 13″ x 19″ prints from the scanned full frame were perfectly feasible. But start cropping and the resolution of the scanned file is simply inadequate. And that even applies to the highest quality scans made with a 36mp Nikon D800 and a dedicated ‘scanner’ setup. The scan was running out of resolving power way before the lens did and, let’s face it, who wants to depend on the tender mercies of the USPS and the interminable wait to get the mediocre scanned results from a commercial processor?

Knobs and buttons: The design philosophy of the M10 could not be more different from that of the typical DSLR. On my Nikon D800 I count no fewer than 15 physical controls on the back plus another 11 on the front for a total of 26.

Control madness – the rear of the Nikon D800.

Compare with the rear of the M10:

Severity and simplicity – the rear of the Leica M10.

The front adds just 3 controls. The design philosophy of the Nikon takes as many controls from the LCD to the body as is possible but in practice I find you set your favorite settings and hardly ever use these. The M10 allows you to place a handful of favorite settings on the screen which is first seen on the LCD when ‘Menu’ is pushed. Thereafter a second push on the Menu button gives you the myriad of settings which digital cameras revel in. Minimalism trumps maximalism in my book.

Resolving power: Some examples in later installments of this piece will show the true resolving power of my four M lenses – the 35mm Leitz Summaron f/3.5 RF, the 35mm Canon LTM f/2, the 50mm Canon LTM f/1.4 and the 90mm Leitz Tele-Elmarit f/2.8. In aggregate these cost me less than one modern used Leica lens and I rather suspect that the costliest, the 35mm Summaron, will be up for sale soon, the goggles a needless and clunky reminder of the limitations of the M3’s viewfinder, as the M10 has native frames for the 35mm Canon, which also happens to be 1 1/2 stops faster.

A related reason is that exposure measurement with the M3 is too slow for the street candid work I favor and, by contrast, every digital M body comes with aperture priority auto exposure. Sure there’s still no autofocus but with the speedy rangefinder and zone focusing that’s not a serious impediment to fast work. Yes, there’s no IBIS but I don’t miss it. I’m (still!) steady enough. And the alternative of using my Nikon D800 with its immense mass and weight for discrete street work does not solve.

In Part II I will look at the mysteries of 6-bit lens coding, proper rangefinder alignment and other arcana.