Yearly Archives: 2025

A cheap 21mm finder for the Leica

Cheap and cheerful, it does the job.

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

Back in the day when I owned a 21mm f/2.8 Elmarit ASPH (they were affordable three decades ago) I used the genuine Leica 21mm finder. That ran some $250 back then and it was pretty awful, with heavy barrel distortion. Today you can spend $1000 on a new one or $400 on the Zeiss (Cosina) version. Reviews suggest that the Zeiss is every bit as awful but you leave with $600 in your pocketbook.

Used beater Leica finders can be found for $300. Voigtländer used to make a couple of versions – a clunky and ugly plastic one (also sold under the Ricoh label) and a rather elegant metal torpedo type which included frames for a 25mm lens and came with a satin chrome or black finish. It’s so-so by all accounts and used ones crop up occasionally for $150 or so.

Why am I writing this? Well, when I reviewed my recently acquired 21mm f/3.5 Voigtländer VM Color-Skopar lens I suggested I would use live view to chimp the rear LCD screen as a composition aid. Well, forget that. It’s a poor experience. You hold the Leica like an iPhone, looking like a real twit, and the display is seldom bright enough to see much in bright light even when set to maximum brightness. So I shopped around and came across this dirt cheap plastic finder which ran me $26.40 shipped from a US seller on eBay:



At that price it’s not a great risk to try.

It’s not going to win any prizes for looks but, amazingly, despite the high barrel distortion (what else is new?) it delineates the field of view of the 21mm lens accurately side to side and top to bottom. It’s also very bright, has no frame lines, defeated all my efforts to photograph an image through it and weighs just 5 grams/0.2 ounces. And it’s a nice tight fit in the M10’s accessory shoe and will not fall out even if nudged. There is no lock on the foot and none is needed. It’s also tiny and fits nicely in my shoulder bag. Sharpness drops off to the sides of the view but not enough to make composition difficult. It’s also set back too far in the accessory shoe meaning that you get a part of the camera’s top plate in the view, but it’s nothing you cannot work around. And it beats chimping.



Tiny.

The finder protrudes slightly behind the top plate but that’s not an issue in use. I may eventually take a hacksaw to the foot to mount it further forward, more to avoid seeing the top plate of the camera in the view than anything else.



Rear protrusion.

I have no difficulty using it with eyeglasses and the plastic should preclude scratches to my eyewear.

Try it. You might like it.

Leica M10 – the Focus button

Obscure and under appreciated.

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



The Focus button.

In the schematic of the camera on page 122 of the English instruction book Leica refers to the button as the ‘Focus button’. It’s in the same location as the rewind release lever on every film M body or, for fans of the early M2 design, where the rewind button used to be. A nice nostalgic touch.

But references to the Focus button are scattered in the manual and the word does not even appear in the index. Plus, the name is misleading.

The first mention, on page 165, states that the Focus button can be used to enlarge details in live view mode to aid focusing. The process is somewhat convoluted and of no interest to those, like me, who never use live view for focusing. This is first and foremost a rangefinder camera, for heaven’s sake.

The second mention, on page 170, states that the Focus button can be used to set exposure compensation by holding it depressed while turning the thumbwheel. This is most useful. With the thumbwheel enabled for exposure compensation I have found that it gets nudged from the zero position just carrying it over a shoulder. So I have turned that functionality off in Menu->Customize Control. The problem with the Focus button approach is that it’s quite difficult to depress that button as it does not protrude sufficiently from the body. Once depressed the thumbwheel does indeed dial in exposure correction, regardless of how it is set in Customize Control.

So the answer is to make the button more prominent, which is easily done with these:



Plastic kitchen drawer bumpers.

I understand these are a special order item from Leica in Germany, priced at $99.95 each. The order code word is DUMMY. Also, there’s a 9 month waiting list and the red version (REDDUMMY) runs all of $149.95. I bought 100 from Amazon for $7 because, you know, I am cheap. That little lot should last me a while.

Before installation a quick swipe of the camera button’s surface with isopropyl alcohol (use vodka if you bought a DUMMY or DUMMYRED from Wetzlar, and consume after installation) removes any traces of finger grease.



Installed.

Be sure to buy 1/4″ (6mm) diameter buttons as they will not be impeded by the surround to the Focus button. Anything larger does not work. I found the stock adhesive too weak for permanence so wiped it off with some acetone and used 3M yellow Super Weatherstrip and Gasket adhesive for a better bond. This is applied to both surfaces, allowed to become tacky (2-3 minutes) and then the bumper is put in place using fine tweezers. If needed the bumper is still removable, if not easily so.

Now the Focus button is really easy to use and you can clearly feel when it has been activated. (In the M11 the button was moved to the top right of the top plate, a much better position, and the mounting ring around the periphery disappeared. That’s the German version of Kaizen at work. It just takes the Germans longer).

The third mention of the Focus button is on page 174 of the instruction manual. Set the shutter speed dial to B, wake the LCD with a press on the central button of the directional pad and hold the Focus button for one second. The range of slow shutter speeds from 8 seconds and up is displayed and can be set with the thumbwheel.

Thus two of the three known uses of the Focus button have nothing to do with focusing.

I have the latest known version of the M10’s firmware installed and, sadly, there is no provision to program other functions to the Focus button. You would think that would be a line or two of code. Oh well.

Automated file import in Lightroom

6-bit coding comes into its own.

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

My earlier piece on 6-bit coding of Leica M-mount lenses concluded with the following codes for my four lenses:




Lightroom stores lens correction profiles, which correct for vignetting and distortion, for the first three. Strangely the Tele-Elmarit is missing.

While 6-bit coding corrects for edge color effects in-camera, there is still a need to apply lens corrections in LR or LRc for the best results. Ordinarily this is done manually, frame by frame, a very laborious approach. You have to check the lens maker and then choose the correction profile from a very long list, one frame at a time. Not good.

Here is how to have Lightroom do that automatically when the files are imported. Even if the imported files were made with more than one lens, the correct profile will be applied to each, along with chromatic aberration correction. Here’s the process.

Take a picture with each of your 6-bit coded lenses and import those into LR or LRc. Go into the Develop module on the first image and scroll down to the ‘Lens Corrections’ pane at right. Check the first two boxes as shown below. My examples are specific to the lenses I own. Choose as appropriate for yours.

21mm f/3.5 Voigtländer Color-Skopar Aspherical VM:




  • Click on ‘Make’ and choose ‘Voigtländer’
  • Click on ‘Model’ and choose ‘Voigtländer VM 21mm f/3.5 Color-Skopar Aspherical’ from the long list
  • The correct Adobe profile will appear in the box ‘Profile’
  • Click on the drop-down ‘Default’ above under Setup
  • Click on ‘Save New Lens Profile Defaults’
  • My 21mm Color-Skopar is 6-bit coded as a Leica 21mm f/2.8 Elmarit pre-ASPH, which is what Lightroom sees in the imported file
  • You have now instructed LR that every time it’s importing a file with the 6-bit code for the 21mm f/2.8 Elmarit-M to apply the profile for the 21mm f/3.5 Voigtländer VM Color-Skopar Aspherical lens.

The next time you import a file taken with the Voigtländer lens, the correct correction profile will be applied along with correction of chromatic aberrations.

Now repeat this process for files taken with your other lenses, selecting the appropriate Make and Model each time, then saving the result. Here are my settings for the other three lenses I own with 6-bit coding. Amazingly LRc has corrections for the two Canon lenses, each over 50 years old:

35mm f/2 Canon LTM:




50mm f/1.4 Canon LTM:




90mm f/2.8 Leitz Tele-Elmarit:




In the case of the Tele-Elmarit there is no lens profile stored in LRc so I chose the one for the 90mm f/2.8 Elmarit-M which is very similar. Both lenses are almost distortion free so you really do not have to check the ‘Enable Profile Corrections’ box, but you still want to correct for chromatic aberrations.

Now on your next import these profiles will be applied automatically. The next step is to correct the lens’ names in EXIF data using the tool I describe here which takes little time and allows the serious business of post-processing to commence.

21mm f/3.5 Color-Skopar VM for the Leica M

An excellent and inexpensive ultra-wide.

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

A brief history of Leica 21mm lenses:

The history of Leitz and Leica’s 21mm focal length lenses for the M body is long. It starts with the 21mm f/4 Super Angulon which came in LTM and M bayonet mounts. Possibly owing to a lack of resources Leitz delegated design to Schneider Kreuznach in the Rhineland. Schneider had a long and distinguished history of making lenses for large format cameras. Now they would apply their skills to crafting the widest lens available for the 35mm format. Characterized by fairly severe vignetting wide open and by a deeply protruding rear element assembly the lens was, nevertheless, a startling technical accomplishment and opened up new vistas for photographers willing to exploit the very wide angle of view.

Introduced in 1958 the optic sported no fewer than nine elements. While we take 12mm ultra-wide optics for granted today, 21mm was as wide as it got back in 1958. Not content with what they had accomplished Schneider and Leitz had another go, coming up with the improved 21mm f/3.4 Super Angulon in 1963, a lens which soldiered on until 1980. The number of elements dropped to eight and performance improved but the rear still protruded mightily into the throat of the camera. I mention this in the context of later digital sensors which do not take kindly to lens elements very close to the sensor. The obliqueness of the light rays striking the sensor makes for color artifacts which are tough to correct.



A handsome lens. The 21mm f/3.4 Super Angolan.
Note the deep rear lens cap to accommodate the protruding elements.

After several variations on the theme Leica now lists two 21mm lenses – the 21mm f/3.4 ASPH Super-Elmar-M and the exotic 21mm f/1.4 ASPH Summilux-M. Both include wallet emptying pricing and aspherical elements and by all accounts are the finest 21mm optics on the planet. I do not propose to find out.

The competition steps in:

When patents on the Leica M bayonet lens mount expired other makers saw opportunities to market 21mm optics for Leica M cameras, always at far more affordable prices. Now there is a veritable cornucopia of availability, with most adopting a retrofocus design which sees the rear element well clear of the focal plane, ideal for use with digital sensors. Prices are as low as $400 if you like Chinese products.



The 21mm f/3.4 VM Aspherical Voigtländer Classic
version of the Color-Skopar on the Leica M10.
Aperture and focus rotation directions are identical to Leica lenses.

Voigtländer/Cosina:

Voigtländer (now Cosina, Japan) updated its 21mm f/4 Color-Skopar, designed for film cameras, to the 21mm f/3.5 version with a retrofocus design aimed at digital Ms, and I recently acquired a mint used one for $400, overpriced lens hood and original box included. New that set runs $750 at B&H. The lens comes in three versions, all with the same optics, with the ‘Classic’ version introduced in 2018. The Classic is black and chrome, above, and the two more modern looking versions, one silver the other black, were introduced later.

Adding 6-bit coding:

Given the success I have had with coding my two Canon LTM lenses adapted to the Leica M mount, the first order of the day with the 21mm Color-Skopar lens was to add 6-bit coding. This is especially important with a wider lens as the protruding rear element is typically a likely cause of color artifacts. 6-bit coding tells the camera’s software to correct these, which it does better than Lightroom. The M10 firmware only shows two 21mm Leica lens options, the pre-ASPH 21mm f/2.8 Elmarit-M and the 21mm f/2.8 ASPH Elmarit-M. The later Super-Elmar and Summilux-M are not choices, so even if you code for these topics you will not get the related result. I tried. The lens was reported as a 21mm f/2.8 Elmarit-M.

On many Voigtländer/Cosina lenses there’s a groove in the mount where painted on codes will not be erased through friction between lens mount and body flange. Probably a neat way of sidestepping Leica’s patented engraved coding pits. Luckily the Color-Skopar has this recess.



The machined groove is clearly visible and
will retain 6-bit ink codes without friction wear.

Unlike the two Canon LTM lenses which required LTM-to-M bayonet adapters, the Color-Skopar comes in an M mount making it trickier to correctly place the 6-bit codes, as the lens comes without the corresponding pits machined in the mount. You need a precision template to accurately place the code ink markings.

All credit for what follows goes to reader Yukosteel on the Fred Miranda site, who developed a file for 3D machining which generates an accurate coding template. I ordered the template online from Xometry by submitting the Yukosteel 3D printer coding template file found here. Nice work by that person. The cost was a very reasonable $7.94 shipped and the tool can be reused ad infinitum. A small protuberance fits in the cutout for the lens locking catch for proper positioning on the bayonet mount and you can then paint in the required codes using the tool’s cut-outs, with a non-shiny black ink pen. The fit is perfect with no play.



The template fitted to my 6-bit coded 90mm Tele-Elmarit.

The point of first fitting the template to a coded lens – one known to work correctly on the M10 – was to check that the openings for coding align exactly with the existing 6-bit pits. They do. Well done Xometry and Yukosteel.



The rear of the template shows the locating peg
(circled) for the camera’s lens locking pin location on the lens.

As with the two Canon optics, I took test images at full aperture with the 21mm Color-Skopar trying each of the M10’s two 21mm lens profiles, determining the best result in LRc. There was very little to choose in terms of color fringing at the extreme edges whether uncoded or coded for the two Leica optics. Once done, I looked up the corresponding 6-bit code in this table. The Leica 21mm pre-ASPH f/2.8 Elmarit-M was the best choice and the code is 000001, with ‘1’ indicating black paint and ‘0’ meaning do nothing. The template is fitted to the Color-Skopar and the Uni Ball pen used to color the indicated pit black. Done. Without a template your chances of accurately placing the codes are low and for under $8 why wouldn’t you do it right first time?



The coding template is fitted to the mounting
flange and the ‘000001’ code is added.
This takes all of ten seconds to do.

Viewfinding:

With the advent of live view in the Leica M240 and all subsequent digital Leicas (excluding the LCD-less ‘D’ variants) the need for a separate viewfinder for framing went away. You can still use an accessory shoe mounted finder of course but for most chimping the LCD display does the trick. That’s what I propose as even used 21mm finders from a variety of makers seldom sell for under $200. If the live view approach fails I’ll look into picking up one of those. As to focus, the depth of field with a 21mm lens is so great that even guesstimating at just about any aperture will see everything in focus. However, to be accurate, the rangefinder works just fine – far better than is needed in fact.

Optical design and filter choice:

The lens sells new for $650-$700 depending on the external finish (the optics are identical), and includes an aspherical element. (A commonplace in modern lenses, but deemed insanely exotic when the first lens thus equipped, the 50mm Leitz f/1.2 Noctilux, was introduced in 1966. Lens grinding technology was insufficiently advanced at the time so the two aspherical surfaces had to be ground by hand!). Add $99 for the ridiculously priced Voigtländer lens hood. The Type I (mine) weighs in at a mere 180 grams – 6.3 ounces – without the hood. By all accounts the earlier f/4 version should be avoided if use with a digital M is contemplated – the peripheral color fringing is pretty bad and hard to correct. The filter size is the standard Leica 39mm and I opted for a thin one to avoid any risk of vignetting. Cosina Japan’s specifications sheet can be found here.

The lens is tiny and with a slim UV filter fitted weighs just 185 grams/6.5 ozs. For comparison the 35mm f/2 Canon LTM with bayonet adapter and UV filter comes in at 139 grams/4.9 ozs. Fit and finish are all metal and Leica quality, the focus collar resistance is just so and the apertures are in half click-stops through f/22. Small protuberances on the aperture ring make it easy to grasp. The black rimmed UV filter not only serves to protect the front element, it also masks off the poorly thought out chrome bayonet front ring which can only be a source of reflections and flare in bright lighting. The distance scale is marked in meters only and the depth of field scale is very hard to read, and only extends to f/11. The 50+ year-old Canon’s DoF scale is far superior in this regard. Not that big a deal as with a 21mm focal length lens almost everything is sharp near to far.

Adding a red indexing dome:

The lens mounting index – a thin red line – is awful, being small and very hard to find. I determined to add a red indexing dome, much as I did with the two Canon lenses. I’m a frequent lens changer in the field and regard the addition of a proper index essential.

What follows is not for those inexperienced with machine tools. I worked in a machine tool shop as a kid so the requisite skills are ingrained. If this is new to you delegate the work. I took a drill to the lens this morning as the area where I wanted to place the red indexing dot is serrated and could not provide a proper glue base. The wood index would inevitably be knocked off in use.

I used a small drill press and a machinist’s vice, using a slightly oversized drill. You cannot do this with a hand drill – the bit will slip and your lens will be marred. The red dot’s diameter is 0.1315” so I used a #27 (0.1465”) drill – call it 1/100th inch oversize. That alloy coated brass ring proved to be very hard so I had to take it easy, a small bite at a time, when drilling. Everything had to be rigidly bolted to the drill press’s table to prevent the drill bit from wandering or the lens moving. Quite why Voigtländer did not add this beats me.

The JB Weld epoxy takes 24 hours to dry.



Measuring the red indexing dome.



A slightly oversized drill is used.



Scotch tape sees to it that the epoxy does not spread to where it is not needed.



Installed.

The red indexing dome and the related drilled hole are immediately adjacent to the focus collar and if you get any epoxy on the junction your lens will be locked and unable to focus. It bears repeating – if you are not comfortable with machine tools delegate the work.

Lens hood and rear element protrusion:

The lens hood cannot be fitted when a filter is mounted so it’s for sale. Poor design. I would rather have a protective filter than a clunky hood without a filter fitted. The rear element does not protrude beyond the rear guard ring, meaning the lens can be carried in a shoulder bag without a rear lens cap fitted without fear of abrasion to the rear glass.



Both the 21mm Voigtländer and the 35mm Canon LTM lenses are
very small indeed.Canon did a far better design job on the
DoF scale than Voigtländer.

Focusing:

The Color-Skopar has a handy small protruding nub for focusing which works well, but sadly there is no infinity lock, making removal of the lens a tad tricky given how narrow the rear serrated ring is. The focus throw is a short 120 degrees with the closest 0.5 meter focus distance inside the 0.7 meter minimum limit of the rangefinder. Use live view below this distance. Ordinarily a short focus throw suggest less precision in focusing but again the very short focal length of the Color-Skopar overcomes even large focusing errors.

Performance:

Performance with 6-bit coding in place? What minor vignetting exists is easily corrected in LRc which includes a lens correction profile for the lens. That profile also corrects minor barrel distortion, handy to know for architectural work. I can see absoloutely no color fringing at any aperture, likely a combination of the aspherical element, the distance of the rear lens from the camera’s sensor and the 6-bit coding. That all sounds horribly complex but in practice happens invisibly. Full aperture is usable across the frame for large prints with the lens peaking at f/5.6 and staying there through f/11. Diffraction kicks in at f/16 and f/22 so for pin sharp large prints these apertures are best avoided. I would say that full frame 36″ x 48″ prints at any aperture are fine but the two smallest f-stops start to show resolution drop-off in print sizes larger than this. In other words chimp in LRc at 100% and everything is perfect. Up that to 200% – a monster print or a massive crop – and the aberrations start to show if the viewer sticks his nose in it.

The wide angle optical design world has come a long way since that 21mm f/4 Super Angulon of 1958. Simply stated this is an extraordinary piece of optical and mechanical engineering at a bargain price for a mint used example. Even bought new the lens is a bargain. Given the level of performance of the Color-Skopar I am rather mystified why anyone would pay $4,000-$9,000 for the current Leica optics. The way I see it, I paid ten cents on the dollar for a stellar ultra-wide optic.

A couple of images:



Leica M10, at f/8. Note the acidic greens. Snapped at the Golden Hour. No flare.


These wetlands, replete with bullrushes, are a sanctuary for redwing blackbirds.

More pictures to come once I hit the streets.

Orange

A cousin of red.




Click the last image for a big version.

Kodak Ektar 100 does a good job with orange. So does the M10 in the last image, the difference being a large jump in resolution thanks to the fine 24mp sensor in the M10. The 35mm f/2 Canon, some 5 decades old, is outstanding.

Leica M3 and M10, 35mm f/2 Canon LTM. Noritsu 1800 TIF film scans (first four images) by The Film Developing Co.