Sigma SD bodies... why not just switch mounts???

Discussion in 'Mirrorless Digital Cameras' started by c4-contemporary-art, Apr 16, 2005.

  1. I've been reading the comments on the sigma SD cameras and am surprised
    so many people are uptight as hell about the camera mount - and being
    stuck to sigma lenses.. why don't you just put a nikon or canon mount on the
    thing if it's that big a problem..?? What'll it cost?? $80 ??? MAYBE...?? Not
    more than $120, surely!!

  2. Why didn't I think of that...
  3. Great idea. Jonathan, do you have a source for these mounts by any chance? I'd like one to use the KM Maxxum lenses.

    (I'm going to guess that it's a little teensy bit more complicated than it might seem....)
  5. Yeah, just take the mount out of an ald canon body and make it fit on a Sigma. Then simply use a hex editor to edit the firmware so this Sigma body actualy knows how to AF these things.
  6. Yeah.... there's this new thing called manual focussing. Crazy huh?? Well,
    the sigma mount I SAW appeared simple enough. Just phillips screws.
    You'll lose AF or any lens control - but if you actually care about your glass -
    it should be irrelevant. Though I didn't consider that the body might NEED
    some sort of electrical signal coming FROM the lens. Does anyone know if
    this mightb e true - or would one have to ask a Sigma Tech. At the very least
    though - all you skeptics - I'd read somewhere (here or DP review) that one
    could also get adapters (although I really can't understand how that would
    work since it would change the lens to sensor distance.

    Perhaps it's a question for Mr. Grimes to answer...?

  7. Given that the flange to film distance is likely to be different for Canon and Sigma - I seem to remember reading that Canon's was one of the lowest, hence the availability of adaptors to use lenses such as Leica R - I can't see this having a chance of working.
  8. Will the replacement mounts be the same diameter and thickness, have the same size screw holes, in the same places?<br>Will the rear of the non-Sigma lenses clear the Sigma electronics contacts and the dust shield right behind the mount? <br>With no electronic connections, how will you stop down the lens aperture, or will you be content to always shoot wide open?<br>And what's so great about the Sigma body in the first place to make any of this worthwhile?
  9. Well, it's actually more common to have the odd Canon lens converted over to Sigma mount. The typical SD body owner already has some Sigma mount lenses. There are several people who do this and sell the converted Canon lenses on a popular (but unmentionable) auction site (hence refered to as PAS).

    The conversion of the body to Canon mount is much easier than Nikon mount. Canon and Sigma share a 44mm registration distance, so you don't have to "build up" the mount to hit the 46.5mm Nikon registration. The Sigma AF protocol is a copy of the Canon protocol (serial messages, contact arrangement, etc) so if you just connect a Canon flange to a Sigma body AF, exposure control, and metering all work. A Nikon lens will be restricted to manual focus and stopped down metering.

    You'll need a Canon service manual to provide the correct part numbers for ordering. You can find these online in PDF form, or for sale on PAS. You'll need the lens mount, several spring clips that attach to the back (separate part numbers). You probably want an EOS3 manual, I think that's the first one where the mount is a decent quality solid metal.

    If you don't want to permanently deface the SD body, you'll also need a front "bullnose" from Sigma parts and service, so you'll also have to track down a Sigma service manual.

    When the recent UK price reductions for SD10 hit the US, I'm going to try this myself.

    Have fun.
  10. I think Sigma would benefit if they scrapped their mount and switched to the 4/3 mount used by Olympus. It's an open standard and wouldn't cost them anything to licence it. If they did that then possibly they might sell some cameras in the U.S.
  11. Wow, so many questions. But none are really hard...

    Craig - yes, the Maxum lenses are about the most complicated. Your mount conversion would need to duplicate the Minolta mechanical aperture linkage, or you would always have to compose, focus, meter, and shoot with the lens stopped down to its smallest aperture. Personally, I wouldn't try this conversion, it's much uglier than the Canon conversion.

    Bas - sarcasm aside, the Sigma SA protocol is an exact copy (serial messages, signal levels, pinout) of the Canon protocol. Just connect a Canon flange to a Sigma body or a Sigma mount to a Canon lens, and it works...

    Jonathan - Sigma bodies can operate just fine (in stopped down metering mode) with a mount conversion that is purely mechanical. You can put a SD10 on a T-mount and use it on telescope or microscope, or use a simple adapter for M-42 lenses (something very popular with SD10 shooters).

    Steve - The Sigma registration distance is the same as the Canon.

    Paul - the Canon mount has a larger diameter than the Sigma, but there is room to machine the Sigma front area to fit the Canon mount. You'd have to add some support structure so that there would be places for the screws to land. As I mentioned before, the Canon protocol and Sigma are identical, connect the Canon mount and the lenses stop down just fine. The Canon lenses do clear the dust protector. As for "what's so great about the Sigma body in the first place to make any of this worthwhile?", several things. First, the dust filter, which removes with a single screw, is also the IR blocking filter. Remove it, and the Sigma SD10 shoots an ISO 400 equivelant in IR. My Nikon D100 shoots an ISO equivelant of 10. The Sigma offers 40x the IR speed. With the right filter, you can pull UV off the blue channel, IR off the red channel, and do wide spectrum imaging at high speed in a single shot. Canon users, unless they want to pay big $$$ for the specialty 20Da (astrophotography edition) have no IR solution that gets them past fractional ISO, like ISO 0.2. A converted SD10 gets them almost 1000x more speed. And, they're going for the equivelant of $600 in the UK ;)

    Bob - as far as why you didn't think of that. It seems to be your nature to look for things to ridicule, rather than looking for way of helping people. This is quite an unfortunate attitude for a moderator of this siet and the author of many of this sites technical articles. I've only recently come in contact with you, so I don't know how long you've ehxibited such behavior. Have you recently had a personal tragedy that has left you bitter?
  12. John, I don't see Sigma moving to 4/3, for a number of reasons.

    First, they would have to release their entire lens line in 4/3, while still maintaining it in SA mount for the existing SD9 and SD10 users. Right now, all they have to do is release some of the more popular and better selling lenses in SA mount, for the Oly E-1 and E-300 users.

    Second, they would need a 4/3 system sized sensor. Right now, it sort of looks like Foveon (the company) is in a "holding pattern". I don't think Sigma sales volumes are high enough to justify the R&D for new sensors.

    Third, that "open standard" is a sticky issue. It's not a requirement that an "open standard" be free. You might have to pay royalties to use it, or you might have to pay money (or sign an NDA, or both) to get access to it. The only requirement for an "open standard" is that it be availiable, to everybody, on the same fair and reasonable terms. I believe that the Oly 4/3 system fails on this definition of "open". I've called and written both Oly and Kodak on numerous occasions, to try to get access to the standard, or at least find out what the licensing terms are. Can't even get a "no, you can't have it" response.
  13. Good to know about the registration on Sigma cam, Joe. This gives a bit more leg room to work/mount lenses.

    With its removable filter, the SD-10 is an attractive camera for me for UV/IR captures (although, the D70 with its flimsy filter is great).

    Stop down metering (does the SD-10 meter with anything? I hope it is not like the Nikons) is not a big deal.
  14. I had been told that the same person who designed the Canon mount also designed the Sigma mount. I didn't realize that they were so similar. I wonder what S.K. Grimes would charge to modify a Sigma to take the Canon lens?
  15. I think Sigma just needs to just offer the SD body with an EOS mount. After all, the Kodak SLR/c (EOS mount) uses an EOS-mount body sourced from Sigma. The SLR/c body is based on the SD-10 body.
  16. Thanks much for the encouragement, Joseph...! Anyway - since my interest
    is in the nikkors, it seems to me the way to approach this would be to take a
    pirated nikkor mount and mill the backside down a mm or two and then
    drill & countersink new holes in the nikon mount to interface with the
    tapped sigma mounting holes - and just leave the electrical connections at
    this point broken.

    I suppose the alternative - though only really cost-effective if you're
    planning to use one or two lenses - would be to have existing nikkors fitted
    with a sigma mount on the lens end - though you'd need to add a spacer to
    compensate for theexpected thicker mount on the nikon body that the
    sigma lacks. Perhaps this would be the more likely way to go if you want to
    retain the potential for future use of sigma and sigma-mount lenses.

    Well, despite having raised the ire of a few souls, I am glad that I launched
    this somewhat contentious post. I've certainly gotten more than I'd hoped
    for from it - which are details in how to actually go about something like
    this.. as well as (hopefully?) made a few people consider possibilities they
    might not previously have....
  17. Jonathan, Why trouble yourself so much?

    Pick up a Nikon-EOS adaptor and you are set!
  18. Sorry - not really interested in the EOS - just trying to make the sigma work
    for me.

    (yes, yes... I KNOW you were trying to make a joke...!)
  19. Vivek - yes, the Sigma meters with anything, stopped down. The only DSLRs currently on the market that don't have stopped down metering are the Nikon mount ones: Nikon D70 and D100 (if D100 can be considered to be "on the market"), Fuji S3, Kodak SLR/n.

    John - that's a rumor that I haven't heard. Interesting. And it's probably worth a call to Grimes.

    Peter - ah, if we could just get an SLR/c bullnose and front mount cheaply out of the Kodak or Sigma oarts department...

    Jonathan - you're welcome. Putting a Nikon flange on the Sigma body means going in the other direction, though. You don't have to mill away material, you probably have to add a couple of mm. Picture a large washer under the mount. I would pull the front mount off a Nikon BR-3 ring. You can get a used BR-3 under $10, and it's got a lens locking pin and spring loaded release lever. There is a fellow who sells a retrofit kit for manual focus Nikkors. Remove the Nikon mount and add the Sigma mount. He also has a Nikon adapter for SD10 cameras, but the registration distance difference means you lose infinity focus.

    Jonathan and Vivek - Even though I have Nikon lenses, my first choice would still be to put a Canon mount on the camera. A Canon mount SD10 will be highly sellable (as long as Sigma doesn't bring one out, themselve). And you can use an off-the-shelf Nikon to Canon adapter...
  20. Oh my god. All the possible permutations are making my HEAD spin.

    Let me see if I understand this - WILL any of the current (or not current)
    dSLRs actually TAKE, say, a nikkor manual F-mount lens and automatically
    stop it down? Or is that an impossibility? Would the Nikon and Fujis do this,
    for example?

    Or is it just the cameras you do a mount switch on which you would need to
    manally meter at the working aperture?

    enlighten me. I'm all over the map. I'm going from c8080 to D70 to 10D to
    20D to SD10 to E1 now to poss. S2 or D70 again... though I REALLY have a
    soft spot for the sigma and olympi.

    Someone help me get my priorities straight!

  21. Vivek - sorry I thought you were poking fun at my originating post. Maybe
    this IS a possibility. I'm starting to think that lack of aperture linkage might
    be much more of a pain than I was hoping. I mean - I KNEW what it would
    involve.. I'm just starting to think realistically about it.

  22. Joseph - about losing your 'infinity focus' with this method... this is
    PRECISELY why I was suggesting milling the back of the nikon body ring.

  23. Jonathan, if you put a Nikon lens on a Sigma or Canon camera, you will have to meter at the working aperture. You compose and focus wide open, then stop down (using the aperture ring on the lens), meter, and shoot. If you put a Nikon lens on a Nikon D70 or D100, you won't have metering at all, but you can set the aperture using the ring on the lens, and the camera will remain wide open for focusing and composing, and automatically stop down when you shoot.

    The registration distance and loss of infinity focus are an issue if you try to build an adapter that goes from the Sigma mount to the Nikon mount. The Nikon registration, at 46.5mm, is longer than the Sigma at 44.0mm. If you managed to hold a Nikon lens so that its bayonet interleaved with the Sigma bayonet on the camera, and held it exactly 2.5mm farther from the camera, you'd have infinity focus. But the bayonets would interfere, and you would not be able to turn and lock the lens.

    If you remove the Sigma bayonet from the camera totally, and substitute the Nikon bayonet, this will not be a problem. Assuming that the metal parts of the mounts are about the same thickness, the Nikon lens needs to be 2.5mm farther from the sensor than the Sigma lens, so you will need to space the Nikon mount farther out from the camera. Unless, of course, the mount you get from a Nikon camera is more than 2.5mm thicker than the Sigma mount you're replacing, in which case you would have to mill the back until the Nikon mount was exactly 2.5mm thicker than the Sigma mount.
  24. Yes - okay - this all makes sense to me. Actually - I was operating under the
    assumption presented by the LAST scenario. Somewhat silly as far as
    assumptions go - but I assumed the difference in thickness was inherent in
    the mounting ring - thus my thinking that milling would be the answer (2
    posts ago and elsewhere).

    Here's another silly question - looking for clarification;

    Why wouldn't you be able to meter on a nikon body with an AI-S lens??

    Also - NOT TO PRESS your generosity with me... is the LEGACY canon glass
    supposed to be superior to that of the LEGACY Nikkors??? I find that hard to
    believe. MAYBE in the higher focal lengths... but it's only the shorties I care

  25. Several questions again.. let me try to answer a few that were intended for Joseph.

    1. Only with the current D2Hs and D2X, you can use your AIS lenses and meter. No other digital (D70, etc) Nikon/Fuji/Kodak will allow you to use your AIS lenses with metering.

    2. I don't know about any legacy of any brands. If you have Nikon lenses, use them. Most are excellent performers. Same goes for Canon, Tamron, Leica, Minolta, etc brands.
  26. All I was trying to ask was "is the canon the more popular camera than
    nikon simply because of the quality of PRE-DIGITAL (legacy) lenses?? " In
    other threads I'd followed people seem to be dumping nikons and
    nikon-compatibles for canon - they were also talking about canon glass in
    the same breath - but I don't know that there is an association - though one
    would ASSUME so... any thoughts anyone??
    I've always assumed the nikon glass to be generally superior - at least in the
    focal lengths up to an including 105mm...

  27. on foveon-site there is a camera-kit with canon-eos-mount. sensor evaluation kit.
  28. Wow, tethered operation and no viewfinder? Think I'll get one right now! ;)
  29. Hi Andrew
    Satoru San at has already made a working Nikon-SA adapter, he has called the "CSN-1", but it is too expensive for him to produce it in Japan.
    He was looking for a business partner that could fund the production of it overseas.
    Here is a picture showing an SA7 fitted with a Nikkor lens and the CSN-1 adapters are shown below the camera body (The two larger rings sitting on top of the CSM422 SA-M42 adapter):
    If you want more details you can email him, but I warn you his grasp of English is probably a lot worse than your grasp of Japanese!...So its best to keep it simple:
    As for myself, I use Mamiya 645 medium format lenses on my SD10, via the "DSGM-1" M645-SA adapter, I engineered myself, and I also use several M42 mount lenses via a CSM422 SA-M42 adapter. In fact I dont use any SA mount lenses at all these days!




  30. Sigma Rear Mount Lens For NIKON Parts /Part auction at the following html:

    It seems that a new US company called Active is manufacturing various different camera parts.

    I wrote to the ebay seller for more answers. I will contribute his/her answer at a later date.
  31. Due to extremely stiff competition D-shell no longer manufactures any adapters and has'nt done so for about 6 months now.
    Another Japanese company, JTAT, now manufactures clones of D-shells CSM422 M42-SA adapter and for the same price as the D-shell adapter.
    However JTAT also manufactures other adapters and accessories for the SA mount that D-shell did not:
    1) A very well made Nikon F - SA adapter:

    2) A pinhole adapter (To be used in conjuction with their M42-SA adapter):

    3) An M42 depth guage (To check how far the rear element of an M42 lens extends rearwards when focussing to infinity):

    The other reason D-shell decided to shut-up-shop was very stiff competition from Poland, and the Aluminium Polish made adapter is still available new for under $40 on ebay.
    The latest news is that a Brass, possibly chrome plated, polish made adapter is being planned, putting in on parr with the quality of the JTAT adapter but for less that half the price.

    Alf Beharie.
  32. Hi,
    I am new to this forum, so easy on me gents, please.

    I have got an SD10 about three weeks ago (ebay) and I love it.
    I also have a few Nikon fast primes (1.4) and used them on the SD10.
    The mounts are different (slightly larger Sigma) but the flange is very close to allow inf focus from Nikon.

    I also got an adapter M42 to Sigma (ebay) and tried to attach a Nikon mount on it. It would have worked but loosing the inf.
    I then just handheld the Nikon inside the Sigma mount and shoot on manual (focus, iris, speed) and here is a sample:
    I think I used either 1.4/85 or 1.2/55 (sorry, don't remember any settings other than 100ASA)

    The idea of replacing the mount (Sigma with Nikon) is achieavable, obviously loosing the AF. Metering will still work (as an indicator)while in manual. I did machine down some of the rear parts of the lenses to avoid hitting the contacts inside the camera mount.

    I will try to replace the Sigma mount with Nikon (including drilling three new holes) and report back.

    I did not have lot of time to replace the filter with something else and see how much light could be gained and how would that affect the ASA and WB settings.

    Other than that, I love the camera. Here are a few more sample shoots:
  33. Is there a mount available to mount CanonFD lenses on Sigma SA?
  34. Yes and No...There are FD/FL to EOS/EF adapters available with optical correcting elements and as EOS/EF and SA share the same 44mm registration distance one possiblity would be to convert one of these adapters into an FD/FL to SA adapter.
    I have one such adapter which I bought specifically with a conversion like above in mind.
    However, I chose to convert my Canon 55mm f1.2 lens itself to SA mount instead of using an adapter as I figured the adapter would almost certainly rob any FD/FL mount lens fitted to it of a stop or two and being as I bought this lens for its ultra fast aperture that would be totally unacceptable to me.
    Currently I cannot focus it to infity on my SD10 and the usable range of the lens is no more than about 10feet(3m)but withing this range its a cracking lens.
    I am also toying with the idea of machining down the lenses mounting boss to allow the rear element to get closer to the sensor when mounted as even if this is'nt enough to allow it to focus to infinty, any increse in the usable range would be greatly welcome.
  35. Please can any help me.... All this talk on swaping mounts has got my head in a spin and trying to work out the best route to take. I have a Sigma SD9, and i think it is a fantastic camera even working with RAW files as you have so much scope to play with in producing your final picture. Lenses! where do i go from here. I have seen the link for the NIKON mount, but has any one tried one and what flaws appeared if any, do you have to stop down etc. Also, the Canon route, attaching the Canon mount sounds good but i am not keen on re-shaping my sigma body, is it easier to attach a Sigma mount to a Canon lens, and if so will the contacts line up or is a bit of fidling about required. The trouble is i am into MotorSport and i need fast and powerfull lenses but the high cost of a sigma sa lens is just pure crazy when there is so much on offer via eBay at the fraction of the price. I am not to bothered about AF, but the metering side is, as i have to submit my pictures to various people to print. I have contacted SIGMA direct who recomend a Pentax K mount to M42 adaptor. If so, why cant the Pentax mount lens go straight on. I have a Pentax MZ50 lying around with a small zoom lens, can this lens be modified to fit. and go the Pentax route.
  36. "I have seen the link for the NIKON mount, but has any one tried one and what flaws appeared if any, do you have to stop down etc."

    No more "flaws" than you get with other lenses...Some Nikon lenses are very sharp and some are not...Picking the gooduns is easy though as you just pick the ones that have high MTF ratings on sites such as photozone.

    "Also, the Canon route, attaching the Canon mount sounds good but i am not keen on re-shaping my sigma body, is it easier to attach a Sigma mount to a Canon lens, and if so will the contacts line up or is a bit of fidling about required."

    Yes, a lot easier but its possible that some machining down of the mounting boss (the bit of the lens that the mounting plate screws onto)may be required as the Canon EF mounting plate is thinner than the SA one.

    "The trouble is i am into MotorSport and i need fast and powerfull lenses but the high cost of a sigma sa lens is just pure crazy when there is so much on offer via eBay at the fraction of the price."

    Compared to the price of used/second hand lenses of course but compared to the price of new Nikon and Canon lenses they are a steal!

    "I am not to bothered about AF, but the metering side is, as i have to submit my pictures to various people to print. I have contacted SIGMA direct who recomend a Pentax K mount to M42 adaptor."

    He He, somehow I'm not supprised...Selling new lenses is Sigma's bread and butter so dont be supprised when you get a silly answer when you ring up with a question that is'nt going to make them any money!...What were actually referring to is how to fit M42 lenses onto the SA mount NOT how to fit Pentax lenses!...PK-M42 adapters are no good for fitting M42 lenses onto the SA mount...M42-SA adapters are though and there are three types currently available.

    "If so, why cant the Pentax mount lens go straight on."

    They can, providing its not an AF version and you cut off/remove the AA lever and AA lever protector moulding from the bezal ring PK mount lenses will fit straight onto the SA mount.

    "I have a Pentax MZ50 lying around with a small zoom lens, can this lens be modified to fit. and go the Pentax route."

    Personally I dont like Pentax lenses much because Carl Zeiss, Canon and Nikon are generally better all round and I use lenses from all three on my SD10 as well as many others.
  37. I want to use my Nikon lens on sigma SD-14. All the postings have many answers. I think the SD14-F on ebay from virtualcameraboutique is the way to go. Any thoughts on this, has someone used it?

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