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Archive 2011 · *MYTH*: Re-chipping a Sigma Lens
James Markus
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p.1 #1 · *MYTH*: Re-chipping a Sigma Lens


I am hoping someone here knows where I can get this lens (sigma 300mm f4 apo tele macro hsm) re-chipped to work on a Canon 5D mKII. I've read that Sigma stopping doing the re-chipping, but may still do it in the UK. Supposedly it will work at f4 only, and if it is sharp wide open that would be great. But, it is also a macro lens, and I would want to stop it down. I owned the 400mm f5.6 apo tele macro brother to this hsm 300mm version, and it was never sharp wide open. However, it was an f-mount nikon version and worked flawlessly on all my Nikon bodies. I'd even be willing to do the re-chipping myself if someone sells them, and will provide instructions. The few reviews I can find on this lens having me hoping it may be a real gem.

Turns out Sigma has "never" re-chipped any of it's lenses. See last post in this thread for more info....

Edited on Jul 25, 2011 at 09:45 PM · View previous versions



Jul 21, 2011 at 10:57 PM
AhamB
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p.1 #2 · *MYTH*: Re-chipping a Sigma Lens


If the 400 wasn't sharp for you then you probably had a bad copy (or extremly high standards). I know some people who use it wide open only (a version that wasn't re-chipped) and their results look good.

The problem with the re-chipping is that Sigma stopped making the replacement parts. Otherwise I'm sure they'd still do it for you.

I've seen a modification of the Canon mount 300/4 with two buttons on the lens to stop down/open up the aperture. It looked like a relatively simple modification (drilling a few holes and connecting some wires), but you'll need some knowledge about the electronics of course.



Jul 22, 2011 at 04:33 AM
ZoneV
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p.1 #3 · *MYTH*: Re-chipping a Sigma Lens


Here in a German photo board (this thread with some Englisch as well) one has masterd to make a old Sigma lens working with an Atmel AtTiny24 µController.
But there is no commercial version at the moment.



Jul 22, 2011 at 07:28 AM
AhamB
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p.1 #4 · *MYTH*: Re-chipping a Sigma Lens


@ZoneV: Thanks for the link. The lens that I saw was sold on that forum, so it must have used that µC. It looks like the same lens is in a picture on page 39.
So I completely misjudged the level of knowledge of electronics you need to do such a mod!



Jul 22, 2011 at 10:05 AM
James Markus
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p.1 #5 · *MYTH*: Re-chipping a Sigma Lens


Benjamin & ZoneV, Thanks for the replies. The lens is suppose to get here tomorrow.


Jul 22, 2011 at 05:18 PM
James Markus
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p.1 #6 · *MYTH*: Re-chipping a Sigma Lens


Well, the lens arrived, and it is exactly as I expected. Wonderful build quality, and fortunately, better wide open performance than the 400mm f5.6 version I used to own on the Nikon f-mount. Yet, it will not let the camera fire if it is stopped down at all...generating an error code about not being able to communicate with the camera body. Wide open it focuses very fast and is really a good lens. So, to determine if it will be sharp enough stopped down...I came up with an extremely low tech test. BTW...I do have high standards. Generally, on a telephoto, I expect to see individual feather barbs or rami, and not a blurred mess. Testing on birds will have to wait, but for today I shot this....

Full frame






Here is the new f-ring I fashioned out of black cardboard, gaffers tape, and a box cutter






Here is a 100% crop with the lens wide open at f4 at 1/1250th second






Here is a 100% crop with the lens at between f5.6 - f8 at 1/500th second using my home made f-ring taped to the end of the lens.
As you can see...it is sharper stopped down






Side by Side view






I still want to try and get the lens re-chipped. I will try calling Sigma US, and UK Monday.



Jul 23, 2011 at 07:51 PM
James Markus
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p.1 #7 · *MYTH*: Re-chipping a Sigma Lens


Just got off the phone with Sigma New York. Turns out that Sigma has never "re-chipped" any of it's lenses. Prior to 2001 Sigma used ROM (Read Only Memory) chips in it's lens. After that, it used programmable chips so that they could re-program lenses that had become incompatible with newer camera bodies...primarily Canon camera bodies. The lens is turning out to be a real gem - even with my super low tech cardboard f-ring. I will see if I can come up with something a bit more elegant than a square black cardboard taped to the end of the lens to act as a f5.6-f8 ring on the lens. But, here are the results of that cardboard...














Jul 25, 2011 at 08:32 PM
Haifisch M3
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p.1 #8 · *MYTH*: Re-chipping a Sigma Lens


very cool, I use the 400 f/5.6 telemacro
is the f-stop reducer supposed to go in front or would it be better to put it in back (inserted)? my guess is that in back it would give better results

when you are done you should market it on ebay under rechipping...



Jul 25, 2011 at 10:37 PM
 

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James Markus
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p.1 #9 · *MYTH*: Re-chipping a Sigma Lens


I ended up selling my 400mm f5.6 apo telemacro. It just wasn't good enough IQ, but the thing was built like a tank, and was in mint condition. This one is mint too, a is really a nice size...only 7.67 inches long, and is built just as wonderfully as the 400mm. Plus it does have better IQ than the 400mm. Your point about creating a rear mask/f-ring is actually one of two plans I intend to test. In the Nikkor 300mm f4 AFS - The f-ring is the last part between the body and the lens. I had never seen that before, but it is an incredibly sharp lens. The other plan is to place a f-ring mask inside the front element threaded area. I will test both 5.6 and f8 in both configurations, and then just leave the lens setup with whatever way is best. Means some testing, but at least these low tech tests make me believe it is worth the effort. I also will look into AF fine tuning the 5D MKII for this lens as well.


Haifisch M3 wrote:
very cool, I use the 400 f/5.6 telemacro
is the f-stop reducer supposed to go in front or would it be better to put it in back (inserted)? my guess is that in back it would give better results

when you are done you should market it on ebay under rechipping...




Jul 26, 2011 at 01:26 AM
Haifisch M3
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p.1 #10 · *MYTH*: Re-chipping a Sigma Lens


James Markus wrote:
I ended up selling my 400mm f5.6 apo telemacro. It just wasn't good enough IQ, but the thing was built like a tank, and was in mint condition. This one is mint too, a is really a nice size...only 7.67 inches long, and is built just as wonderfully as the 400mm. Plus it does have better IQ than the 400mm. Your point about creating a rear mask/f-ring is actually one of two plans I intend to test. In the Nikkor 300mm f4 AFS - The f-ring is the last part between the body and the lens. I had never
...Show more
that's the first I hear of this
mine is tack sharp at 5.6 the only working aperture
the photozone test also confirms it's sharpness

here is a shot I took with the 400 apo telemacro






make sure to post the results of rear aperture disc stop-down



Jul 26, 2011 at 01:39 AM
pdmphoto
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p.1 #11 · *MYTH*: Re-chipping a Sigma Lens


Haifisch M3 wrote:
that's the first I hear of this
mine is tack sharp at 5.6 the only working aperture
the photozone test also confirms it's sharpness

here is a shot I took with the 400 apo telemacro
http://i971.photobucket.com/albums/ae196/HaifischM3/macro-%20insects/1045-2.jpg

make sure to post the results of rear aperture disc stop-down


My Sigma 400 APO HSM tele macro is also super sharp, from wide open. Much sharper wide open than the 300 APO tele macro I had, which improved considerably when stopped down.



Jul 26, 2011 at 01:51 AM
James Markus
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p.1 #12 · *MYTH*: Re-chipping a Sigma Lens


When I said the 300 was much sharper than the 400 - I meant only among the two lenses I owned, not all 300's and 400mm Sigmas. Your sample photo is of a very contrasty scene - which can look sharp. This shot of yours is the type of sharpness I am looking for...where even in flat light there is good sharpness. The fur of this chipmunk is not smeared...or the barbs of song bird feathers. That is the standard I want.



I can't see the EXIF data in this image, and I don't know how aggressive it was sharpened in camera and in PPing, but SOC...that is what I want.



Jul 26, 2011 at 02:05 AM
James Markus
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p.1 #13 · *MYTH*: Re-chipping a Sigma Lens


It looks like I had the reverse of lenses to you....my 400mm was not HSM, and my 300mm is HSM. Plus my 400 was Nikon f-mount, and the 300mm is Canon mount.


My Sigma 400 APO HSM tele macro is also super sharp, from wide open. Much sharper wide open than the 300 APO tele macro I had, which improved considerably when stopped down.




Jul 26, 2011 at 02:14 AM
Haifisch M3
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p.1 #14 · *MYTH*: Re-chipping a Sigma Lens


mine is also the HSM telemacro version

400mm @ f/5.6







Jul 26, 2011 at 02:29 AM
davidearls
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p.1 #15 · *MYTH*: Re-chipping a Sigma Lens


I had a Sigma 500 that "needed re-chipping" to stop down, and of course, as you have found, it couldn't be re-chipped. I tried to buy damaged Sigma teles that had already been re-chipped, thinking I could send the whole kit to Sigma and they'd do the work. Alas, no luck,

I don't remember if the lens had an aperture ring or not, it certainly wouldn't stop down electronically. If it has an aperture ring, you might be able to stop it down manually using a non-communicating extension tube between the lens and the body. I've never tried it, and don't have the Sigma lens any more, but that's where I'd be looking -



Jul 26, 2011 at 04:22 AM





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