Bit Coded Lenses

Discussion in 'Leica M and LTM Lenses' started by Christilou, Apr 5, 2013.

  1. Christilou

    Christilou Leica Place Veteran

    402
    Apr 5, 2013
    Although I don't own a Leica at the moment (I did have an X1 once :) I have to confess that I put my deposit down on the new M a few weeks ago. Not expecting it to be available any time soon and I'm not even sure I'll go through with the purchase. I need to find a real one to try first! I'm just trying to gather some info at the moment and one of the things I'm not clear on is this bit coding for lenses. I see that some people pay to have their lens bit coded and I wonder if anyone can enlighten me regarding this. Do the new lenses come already coded?
     
  2. Duane Pandorf

    Duane Pandorf Leica Place Regular

    195
    Mar 30, 2013
    I believe most all of the new lenses do come 6 bit coded. I believe I read recently that some of the early production models of a certain wide angle lens did not come with a 6 bit code but Leica was coding those for free if sent back.

    Of course, if your lens is not coded you can manually select the lens profile in the camera. The M9 series has 4 profile presets that you could technically have up to 4 different lenses manually profiled and saved in camera. But then you have to remember to change the profile each time you change lenses. The beauty of have your lenses coded is to take advantage of the auto lens profile.
     
  3. defektive

    defektive Leica Place Regular

    57
    Mar 30, 2013
    In the back of my foggy memory (from my M8/9 days) is a recollection that the coding allows the camera to automatically compensate for some issues that individual lenses have such as colour shift and vignetting as well as allowing EXIF info to be collected.
    Most lenses that are not already coded can be done by yourself or a technician. You can do it permanently by gouging the six notches out of the lens mount then adding the required black and white colouring for that lens to the notches. A temporary option (not recommended by Leica) is to add the black coding marks with a permanent marker to the lens mount without first creating the notches. If you buy any lenses in screw mount there are numerous adapters around that convert them to M-mount and already have the coding notches in place for you to apply the colouring to. There will be others here that have more experience than I on the matter so hopefully someone will add any corrections or extra info.
     
  4. Duane Pandorf

    Duane Pandorf Leica Place Regular

    195
    Mar 30, 2013
    There's a couple eBay sources where you can buy the appropriate mounting plate that already has the 6 indentations to replace your existing one that you can code accordingly. However, the issue is if these third party mounting plates are thicker or thinner than the original Leica mount which could cause some focusing issues.

    It would probably be best to have Leica code the lens to ensure you maintain the factory tolerances.

    As a side note, if you were to read Erwin Puts recent review of Leica's new 50mm lens you'll get an idea of what I mean by maintaining factory tolerances when dealing with a digital Leica compared to film versions.

    Apo-Summicron-M 2/50 ASPH | The TAO of Leica
     
  5. BillN

    BillN Leica Place Rookie

    20
    Mar 30, 2013
    Christina

    you can read about it on the following link - (it is a cheap way to "code" the lens - as was mentioned above not recommended by Leica - but I'm not really sure why)

    BoPhoto.com: M8 coder - simple manual handcoding of M lenses

    I was going to have a go but never did - I have found with my M8 I use my 28mm Biogon most of the time, (it is not coded) - and my personal feeling with the M8 is that it is a "one lens body" -i.e. for me the one lens that I like - the 28mm - so I tend to know what I have taken with which lens - I only have one lens that is coded - the 35mm f2.5
     
  6. usayit

    usayit Leica Place Regular Subscribing Member

    122
    Mar 31, 2013
    Northern NJ
    Some have reported the ink rubbing off leaving residue on the 6-bit code sensor.
     
  7. ajramirez

    ajramirez Leica Place Veteran

    267
    Mar 30, 2013
    Caguas, Puerto Rico
    Antonio
    Christina,

    Since you would be starting from scratch, I would suggest getting lenses that are 6-bit coded. The Summarits are superb performers and not outrageously expensive (by Leica standards). I have the 35 and the 90 and can certainly vouch for their performance.

    You can also get older Leica lenses 6 bit coded by the factory. I did that with my 50mm 2.8 Elmar M. The cost was $250 at Leica NJ (USA) which included cleaning and adjustment of the lens.

    If you purchase non-Leica brand lenses (such as the Zeiss ZM or Voigtlanders) you may or may not need to deal with coding depending on the focal length. Typically, coding is necessary on wide angle lenses to correct for vignetting and color shift. I do not code my Zeiss 50mm 1.5 C-Sonnar, but use manual coding for the 18mm 4.0 Zeiss Distagon.

    Cheers,

    Antonio
     
  8. usayit

    usayit Leica Place Regular Subscribing Member

    122
    Mar 31, 2013
    Northern NJ
    With the rising cost of new Leica lenses, it may be well worth just sending in a good used lens in for coding. It doesn't cost that much.... its a fixed cost. Just call NJ, Leica up get a quote and figure that into the negotiation of the price of the lens. I certainly wouldn't make the lack of a 6 bit encoded mount a deal breaker for a lens an older lens that you "really" want! Some of the most popular lenses from Leica pre-date the 6bit encoded mount from factory.

    Not all of my lenses are coded... I've been meaning to get them coded. Its not really a big deal. The missing EXIF data is really just a minor annoyance. The corrections are more noticeable with wider angle lenses although my 24mm is uncoded and certainly hasn't stopped me from enjoying it.
     
  9. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
    If you use older Leica Thread Mount lenses with an adapter: you can get third party LTM to M-Mount adapters with notches cut for coding them yourself. With the M9 and newer cameras, manually selecting the code works. For Third-party lenses: you can find one that is close.
     
  10. flash

    flash Leica Place Regular

    54
    Mar 30, 2013
    All new Leica lenses are 6 bit coded. Coding does a few things. It passes lens focal length info to an attached flash and for exif recording. It also allows for vignette and colour edge correction although this is only an issue with lenses wider than 35mm. Because coding allows exif data recording Lightroom can then automatically apply lens profiles. I have two non coded lenses and it still bugs me that the focal length doesn't appear in the exif data, even though I know which shots are with which lens.

    Lenses that are not coded or not Leica can be coded. I have the one mentioned above but it's not as good as the Match technical coding kit. Voigtlander lenses have a slot in the mount to make it easy to hand code. Older Leica lenses can be coded by Leica. LTM lenses just need the purchase of a grooved adaptor. Zeiss lenses are the most difficult but if you're handy with a dremel.....

    Gordon
     
  11. Christilou

    Christilou Leica Place Veteran

    402
    Apr 5, 2013
    Thanks for all this valuable info. I was thinking of buying just one really good Leica 50mm and then looking to the Zeiss lenses. My priority probably should be a portrait lens though. Not sure if a 75 or 90 would be best. I mentioned before that I like the Pentax FA77 but was thinking that this would still equate to 77mm on the Leica ff because I thought that the old Pentax FA lenses were originally for FF film cameras. Am I wrong here?
     
  12. ajramirez

    ajramirez Leica Place Veteran

    267
    Mar 30, 2013
    Caguas, Puerto Rico
    Antonio
    If I recall correctly, you were using the Pentax 77mm on a K-01, which has an APS-C crop sensor. To get the same angle of view on the full frame M would require a 110mm lens (77 x 1.5). You would probably be best served by the 90mm.

    Cheers,

    Antonio
     
  13. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
    There are quite a few vintage portrait lenses to choose from in Leica thread mount. The Nikkor 8.5cm F2 and 10.5cm F2.5 are fantastic on the modern digital Leica. I'll upload some shots with the two of them in the sample gallery.
     
  14. Brian

    Brian Super Moderator Subscribing Member

    Apr 3, 2013
  15. Haans

    Haans Leica Place Rookie

    12
    Apr 13, 2013
    Minneapolis, Mn.
    I went through this several months ago. I bought the mounts on Ebay (you have to be very careful about the mounting holes), and converted 3 leica lenses and a CV 15mm screw mount. It's quite a bit of work and a lot of it is making sure the lenses focus well before conversion. If they don't, don't bother. I printed a focus chart and took photos of it, then printed those and compared. Next I took off the original plate and measured the thickness around it in several places and noted that. then I measured the thickness of the new plate and compared them. Taping a sheet of 400 grit sandpaper to a piece of glass, I sanded the back of the plate, rotating and measuring till I got it as close as possible to the original. After cleaning, I screwed the new plate on and took new photos of the focus chart. Printed those and compared to the original. Two of the new mounting plates needed thicknessing. The third was close enough. I used black and white enamel to paint the recesses milled into the plates to code the lenses.
    The screw Mount was a different story. I had to remove the adaptor several times and ended up shimming it a bit. Wasn't that important with the 15mm however, as everything is pretty much in focus, from 3' to infinity at f4.5.
    In summary, it's a lot of work, but I figure I saved a good $600+. Worth it to me.
     
  16. swamiji

    swamiji Leica Place Rookie

    22
    May 17, 2013
    Earth
    Yes all new Leica lenses (just recently the 135mm APO-Summicron) comes coded. But when it comes to older lenses, it's not so good. There is not enough codes for all Leica lenses. So even if you have a M-Coder or have purchased a new mount, often there is not a code for your lens. What you have to do is try out different combinations. But since two of the same type of lens may have quite differently rendering, the choice is not always so obvious. Then if you have a third-party lens it's even worse.

    On the other hand you can just select manual lens selection, and pick your lens. Most older lenses are their (but not all).

    Here is a chart, I found at the L-leica forum, that might help:

    Leica Lens Codes - Leica Forum Blog - Leica Forum Blog