[Leica] IMGs: Finding the “right lens/film/sensor/camera” combination:

[Jim Nichols]

Thanks for the feedback, George.  That seems to correlate with other 
inputs I have gathered.

Jim Nichols
Tullahoma, TN USA

On 9/10/2015 3:38 PM, George Lottermoser wrote:
> On Sep 10, 2015, at 12:29 PM, Jim Nichols wrote:
>
>> Thanks, Ken.  I located a step-up ring and filter at B&H that will work.  My lens does not have an infrared focus index.  Do you have such, or, if not, how did you decide how to focus?  Just by what you see through the filter?
>>
>> Your images certainly appear to be well focused!
> My understanding of focusing invisible spectra
> requires a manual shifting of focus
> once you "know" the visible light focus distance.
> Further each lens, IR filter, and film/sensor combination
> will determine a "different" focus shift.
>
> On my 40 mm Summicron
> with B+W 090 IR Filter
> on M8 Sensor
> This translates to moving the focus ring
> from dead on to the third mark to the right (between 4 and 8)
> This seems to give me accurate focus, even wide open, at 3 Feet (.9 Meters)
>
> Regards,
> George Lottermoser
>
> http://www.imagist.com
> http://www.imagist.com/blog
> http://www.linkedin.com/in/imagist
>
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information
>