6-bit coding - do you really need it?

Bill Blackwell

Leica M Shooter
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To date, it has primarily been the IR issue that has kept me away from the idea of pulling the trigger on an M8.

However, there are some attractive deals to be had right now, so I am currently reconsidering.

Setting the IR issue aside for now, for those of you who have been using an M8 for awhile, is the 6-bit coding really necessary for the lenses to work properly? I am told wide-angle lenses are most important to have coded, but the results I have seen from Zeiss lens users (including the 15mm Distagon) are quite impressive. And these are obviously not coded.

So what's the story?
 
It is about color now the ir issues can happen with black in a photos but also with a lot of grass. getting the lenses coded can be alot easier then you think John Miclh can 6 bit code lens mounts for you. then you just put soem nail polish in the grooves. I have my voigtlander 15 and my zeiss 21 AND 25 6 bit coded and my 50 zeiss although money issues is making me sell that lens. It is a bit of a pain but 15 bucks al shpt for 1 roll of slide film compared to all day shooting for free after the cost of a camera well you get the point. digital is here to stay. Enviormentally it is probaly better in the long run.
 
Any lens shorter than and including 35 mm should be coded; longer, not needed unless you are anal about exif. IR-filters: screw them onto all your lenses and forget they are there. As an old hand at the anti-filter game that was the hardest part for me, but now I am not bothered at all, as the results speak for themselves. Btw, my ZI Biogon 21 is coded, as is my VC 15....
 
"Any lens shorter than and including 35 mm should be coded; longer, not needed unless you are anal about exif."

Why should lenses shorter than and including 35mm be coded? What is "exif"?

"As an old hand at the anti-filter game that was the hardest part for me, but now I am not bothered at all, as the results speak for themselves."

Well, not so easy for me! I have Leica UVa filters on all nine of my Leica lenses and I plan to keep my film cameras. I don't want to futz around with filters when I change back-and-forth.

"... my ZI Biogon 21 is coded, as is my VC 15..."

What code did you use for the 15? Who did the coding? What difference does it make if these lenses are coded or not?

It's like this… Pretend I have been using film my whole life and I know nothing about digital systems.
 
Well, I purchased an M8 this afternoon.

IMO, the verdict is still out if the 6-bit coding is really necessary.

Many thanks to those who have responded so far...
 
Wish I had $6000 to get mine already (M8 + Zeiss Biogon 35mm + M8 Hand Grip + Leica Flash + whatever Tim Isaacs is going to charge for his ThumbsUp)
 
jaapv said:
Any lens shorter than and including 35 mm should be coded; longer, not needed unless you are anal about exif. IR-filters: screw them onto all your lenses and forget they are there. As an old hand at the anti-filter game that was the hardest part for me, but now I am not bothered at all, as the results speak for themselves. Btw, my ZI Biogon 21 is coded, as is my VC 15....

How did you do the VC and how does it work out ?
 
Dear M8 users…
I've had my M8 for about 3 weeks now, and I think the magenta cast/IR-filters and cyan drift problems has come up as some real world issues that I had to handle… The question is of course what is the best solution.

To me the magenta cast has been the biggest problem and the only working solution imo is IR-cut filters (they works well!) Software solutions like actions in PS or profiles in C1 isn't good enough (they also seem to have an effect (negative) on other colours than magenta) and it takes to much time to use (you still have to tweak a lot in PS to get things right).

IR-cut filters are needed whenever you shoot people, both outdoor an indoor, because many people uses fabrics that turns from black to magenta and we don't want that when their clothes are black ,do we?. For landscapes I prefer to take the IR-cut filter off to attain maximum resolution and to avoid any flare created by the filter.

But the new problem these filters create are as all of you know by now the cyan cast/vignetting combination when used on wide angles from 35mm and wider - most people talk about 28mm or wider but from my experience it's an issue even with my summilux 35 1.4 asph.

So, is coding the solution? - Well, I think only partly, because the built in camera software do not handle all the different amount of vignetting/cyan drift, depending on f-stops and the actual light conditions present when and where you take the picture.

Till now I have not coded any of my lenses. With my 50 cron and 75 summilux there are no vignetting and no corner cast, so no coding is needed with these lenses. The only benefit from coding these lenses is the lens information you get stored in your exif files. Some people want and need that. I don't.

Is there another solution?
Thanks to people like Sean Reid and Sandy McGuffog it now seems to be a software solution available named CornerFix that can handle the cyan/vignetting problem with the use of self-created profiles that attaches to the DNG files (you run the files through the software before you do post-processing in PS or C1) and it works just fine with most(?) post-processing software available. I've tried it out by making profiles for all my wideangles from 35 to 15(CV4.5) and the results are just amazing. Dead neutral, no cast pictures!!. The best of all is that this is a freeware (I love those guys..) As soon as you have made your profile library, ConerFix is fast to use and you can even batch-process many files at the time.

If you want to read more go to Sean Reids page on www.reidrewievs.com and have a look at his CornerFix review.

The CornerFix software can be downloaded here:

http://sourceforge.net/project/showfiles.php?group_id=197345

This is how Sandy describes the software in the instruction file:

What is CornerFix for Windows?
CornerFix for Windows is a small utility program designed to fix the “Cyan corners” problem, caused by color dependent vignetting, with Leica M8 digital cameras using IR filters. It has two functions:


● To correct raw M8 DNG files for vignetting, based on a devignetting profile, and
● To generate a devignetting profile from a flat field reference image.

And ( my comment) be sure to read the installation instructions carefully and check out if you have the windows updates needed to run the software ( I had to get this to make it work on my computer)

So, go ahead and give it a try…
Cheers!
 
Taqi said:
How did you do the VC and how does it work out ?

I bought the John Milich adapter, coded it as the WATE and it works like any coded lens , no cyan drift with IR filters :)
 
Antonius said:
Dear M8 users…
I've had my M8 for about 3 weeks now, and I think the magenta cast/IR-filters and cyan drift problems has come up as some real world issues that I had to handle… The question is of course what is the best solution.

To me the magenta cast has been the biggest problem and the only working solution imo is IR-cut filters (they works well!) Software solutions like actions in PS or profiles in C1 isn't good enough (they also seem to have an effect (negative) on other colours than magenta) and it takes to much time to use (you still have to tweak a lot in PS to get things right).

IR-cut filters are needed whenever you shoot people, both outdoor an indoor, because many people uses fabrics that turns from black to magenta and we don't want that when their clothes are black ,do we?. For landscapes I prefer to take the IR-cut filter off to attain maximum resolution and to avoid any flare created by the filter.

But the new problem these filters create are as all of you know by now the cyan cast/vignetting combination when used on wide angles from 35mm and wider - most people talk about 28mm or wider but from my experience it's an issue even with my summilux 35 1.4 asph.

So, is coding the solution? - Well, I think only partly, because the built in camera software do not handle all the different amount of vignetting/cyan drift, depending on f-stops and the actual light conditions present when and where you take the picture.

Till now I have not coded any of my lenses. With my 50 cron and 75 summilux there are no vignetting and no corner cast, so no coding is needed with these lenses. The only benefit from coding these lenses is the lens information you get stored in your exif files. Some people want and need that. I don't.

Is there another solution?
Thanks to people like Sean Reid and Sandy McGuffog it now seems to be a software solution available named CornerFix that can handle the cyan/vignetting problem with the use of self-created profiles that attaches to the DNG files (you run the files through the software before you do post-processing in PS or C1) and it works just fine with most(?) post-processing software available. I've tried it out by making profiles for all my wideangles from 35 to 15(CV4.5) and the results are just amazing. Dead neutral, no cast pictures!!. The best of all is that this is a freeware (I love those guys..) As soon as you have made your profile library, ConerFix is fast to use and you can even batch-process many files at the time.

If you want to read more go to Sean Reids page on www.reidrewievs.com and have a look at his CornerFix review.

The CornerFix software can be downloaded here:

http://sourceforge.net/project/showfiles.php?group_id=197345

This is how Sandy describes the software in the instruction file:

What is CornerFix for Windows?
CornerFix for Windows is a small utility program designed to fix the “Cyan corners” problem, caused by color dependent vignetting, with Leica M8 digital cameras using IR filters. It has two functions:


● To correct raw M8 DNG files for vignetting, based on a devignetting profile, and
● To generate a devignetting profile from a flat field reference image.

And ( my comment) be sure to read the installation instructions carefully and check out if you have the windows updates needed to run the software ( I had to get this to make it work on my computer)

So, go ahead and give it a try…
Cheers!
Please don't post grey, I can hardly read it... The cyan drift is eliminated effectively with coding. See Sean Reid's tests.
 
BillBlackwell said:
To date, it has primarily been the IR issue that has kept me away from the idea of pulling the trigger on an M8.

However, there are some attractive deals to be had right now, so I am currently reconsidering.

Where / what attractive deals?

(Leica warranty is essential in considering any deal it seems to me.)

--Bob
 
I use a 35 Summilux all the time and have yet to see any cyan ****. it is a pre-asph 'Lux and i use the Leica uv/ir 49mm filter in the hood filter tray. this lens cannot be coded, and my 50'cron and 90 tele-elmarit are also not coded and from what i have seen none of my lenses need the coding.

gene
 
I am using several lenses on my M8: 12, 15, 28, 50 and 75. All are with the leica filters and all are coded. very handy with one problem: I am still awaiting a 49mm filter for the 75. the problem this poses is that I have to remember for that one lens, to change the menu setting re. the IR/UV .

the point being, it is better to code and filter them all or none of them. then you just leave coding on +UV/IR on all the time or never.

second point is the wide angle lenses benefit most with the lens detection and filtering with the latest firmware. If you just filter, you will have to get rid of the cyan corners.

the above is what led to the self coded thread to M adapters and filter holders for the 12 and 15 C/V lenses

jm@milich.com
 
I think it's ridiculous that the M8 doesn't simply let you choose a focal length from a menu when necessary. My Pentax K10D SLR is smart enough to offer such a menu whenever I mount a lens it doesn't recognize (this allows the camera's image stabilization feature to work properly with older lenses).

-Dave-
 
I just got a 6 bit encoded 28mm Elmar, this is my first lens that's coded and I'l see if I notice a drastic difference.

Hopefully I wont notice too much of a difference or I'l have to get my CV glass coded.
 
David Kieltyka said:
I think it's ridiculous that the M8 doesn't simply let you choose a focal length from a menu when necessary. My Pentax K10D SLR is smart enough to offer such a menu whenever I mount a lens it doesn't recognize (this allows the camera's image stabilization feature to work properly with older lenses).

-Dave-

That might change in the future.

Cheers,
 
If one is using IR-cut filters for color work with the M8, he or she will need some way to correct for cyan drift with 35 mm and wider lenses. Cornerfix is an option but otherwise, coded lenses and hand-coding is the best way to deal with this. For photographers who've not yet seen cyan drift in pictures made with the M8, IR-cut filters and wide angle lenses - its just a matter of time.

Does the effect vary from one specific 35 mm (or other focal length) lens to another? Yes, in minor ways, because the lenses can vary in contrast, saturation, flare, etc.

Cheers,
 
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