M8 Sees My CV15 As 18mm, Not 16mm

[photolandscape]

Advertisement (gone after registration)

I just got my LT-M8 adapter from John Milich. I checked Carsten's invaluable coding diagram, got some Testor's flat black and white paints, and applied them nicely with a toothpick.

 

The next morning, I mounted my CV15 with IR filter on my chrome M8. It recognized it immediately as a 16mm lens. Excellent.

 

Later in the day, with all the same settings on my black M8, I mounted the same CV15 with the LT-M8 on it. Oddly, it sees it as an 18mm focal length lens.

 

How could that be? The good news is that I seem to get excellent results either way, and most important, the dreaded cyan vignetting is no longer present.

 

Any thoughts on why two different bodies, with the same menu settings in place, would see the lens as a 16mm vs. 18mm lens? Does it even matter?

[stunsworth]

Hi Steve, the camera shouldn't automatically recognise the lens at a 16mm - I assume you've coded it as a Wide angle Tri-Elmar. What should happen is that you're presented with a menu when you mount the lens asking if it's set to 16, 18 or 21. You then need to select the 16mm option.

 

I'm assuming that if you don't respond to this menu it defaults to 18mm - sorry can't remember if this is what happens in practice.

[Paul_S]

Any thoughts on why two different bodies, with the same menu settings in place, would see the lens as a 16mm vs. 18mm lens? Does it even matter?

 

Yes, it does matter, although the difference between setting at 16 or 18mm is small for the CV15+IR cut filter. I think 16mm setting is best (and I forget to switch it from the default 18 to 16mm 50% of the time).

Don't know why 2 different bodies respond different. As far as I know, mounting a lens coded as the wide-angle Tri-Elmar defaults to 18mm (when camera is set to ON+UV/IR). I noticed however, that once set to another value (i.e. 16 or 21) this value might come back later selected when re-mounting the lens if the camera has not been switched off in-between.

[gabriel]

Have you got the latest firmware release 07 installed on both bodiesa

[Guest guy_mancuso]

You need to set it in the menu option for 16mm , it will always default to 18mm if you do nothing and hit the shutter. I would try both bodies again. It really should not come up at 16mm unless you are setting it and use the latest firmware.

 

I have been asking Leica to actually get rid of the 18mm default and just remember the last setting with on and off just like ISO

[doubice]

Make sure that both bodies have the latest firmware (1.107) and that both are set to Lens Detection On+UV/IR. If affirmative, a menu should pop up when you mount the lens, prompting you to chose which (16 - 18 - 21) lens you are using. If you do not chose a lens, the default is 18mm.

 

Best,

 

Jan

[photolandscape]

Advertisement (gone after registration)

Thanks very much to all. This is why I love the forum. For the record, I am using 1.107 on both cameras, with "lens detection ON + UV/IR". Being very farsighted, I may have misread the screen on my silver M8. In any case, I am happy to report that when I mount the CV15 with the LT-M8 adapter, I get the default of 18mm, and I just reset it to 16mm. So all is well. Thanks!

 

After shooting more than 1,000 shots with the CV15 in So. America, without the coding and the LT-M8, I no longer have to deal with the dreaded cyan fringing. Thanks to Sandy and CornerFix, at least I have been able to filter out the fringing in the shots I'll be posting or printing.

 

I appreciate all the ingenuity I see in this forum, and the members' willingness to share their knowledge, opinions, etc.