[Leica] IMG: Bench At San Pedro Valley State Park

[Jim Nichols]

Bob, it's late here, but I am going to stick my neck out.  Feel free to 
chop.

I was always taught that the "normal" lens for any film (sensor) size 
was close to the diagonal of the film or sensor.  For a 4x5 film size, 
this comes out to be 6.4" or 160mm.  So, normally a 6" or 5" lens was 
provided.

Rounding your sensor to 54x40, the same "normal" would be 67mm.

Using the same old geometric relationship for 35mm film, the "normal" 
would be 43mm.  Using this, instead of the usual 50mm for normal, gives 
the following equivalents:

Your 32 is equivalent to a 21mm on 35mm format.
Your 50                                32mm
Your 80                                51mm
Your 150                              97mm

I'm not sure how to handle the shifts.

Now it's your turn. :-)

Jim Nichols
Tullahoma, TN USA

On 7/9/2015 10:05 PM, Robert Adler wrote:
> and why is a basically 54x40 sensor more like a 645 than a 4x5??
>
> On Thu, Jul 9, 2015 at 7:42 PM, Robert Adler <rgacpa at gmail.com> wrote:
>
>> OK. My bad.
>>
>> The image was taken with an 80mm lens and a sensor that is 53.9mm X
>> 40.4mm: I guess that's 645 format. It was also a stitch of two images that
>> overlapped. The back was shifted 10mm to the left (exposing more on the
>> image's right). So certainly not "normal" (not much about me is...). And
>> the sensor was in portrait mode...
>>
>> That said, I'd love to have a table that shows what my lenses are in 35mm
>> format with this sensor AND with 10mm shift and 20mm shift (both right and
>> left shifts of 10mm). E.g., what's my 32mm lens in 35mm format terms
>> unshifted, shifted 10mm and shifted 20mm?
>>
>> I have a 150, 80, 50 and 32... Anyone got an easy spreadsheet?
>>
>> So my apologies for the confusion, but I still like the image though the
>> "perspective seems really strange"....
>>
>>   :-)
>>
>> On Thu, Jul 9, 2015 at 7:04 PM, George Lottermoser <
>> george.imagist at icloud.com> wrote:
>>
>>> Yes. I agree Jim.
>>>
>>> Though 6" would be closer to 152 mm
>>> than 127  mm
>>>
>>> 12" (300 mm) for 8x10
>>> 8" (210 mm) for 5x7
>>> 6" (150 mm) for 4x5
>>> is what we thought of as "normal" in the good ole days
>>>
>>> a note off the iPad, George
>>>
>>> On Jul 9, 2015, at 7:17 PM, Jim Nichols <jhnichols at lighttube.net> wrote:
>>>
>>>> always considered "normal" for a 4x5 to be 6 inches, or, as many Speed
>>> Graphics were equipped, 127mm.
>>>
>>> _______________________________________________
>>> Leica Users Group.
>>> See http://leica-users.org/mailman/listinfo/lug for more information
>>>
>>
>>
>> --
>> Bob Adler
>> www.robertadlerphotography.com
>>
>
>