MF to 35mm lens crop factors

[etrump]

I had a hard time getting a handle on MF focal lengths when comparing them to the 35mm equipment I was used to.

I thought some prospective MF users might be able to use these two spreadsheets.





Hopefully they are accurate.

[Morgan_Moore]

Did this Very rough chart based on 50=80mm rule ..

which basically says a 35mm full frame 645 is equal ish angle of view to a 22mm on 35mmfull frame

[etrump]

Very rough based on 50=80mm rule ..

which basically says a 35mm full frame 645 is equal ish angle of view to a 22mm on 35mmfull frame
[{POST_SNAPBACK}][/a]

[a href=\"http://www.bhphotovideo.com/c/product/213301-REG/Mamiya_210600_35mm_f_3_5_Lens_for.html]Mamiya 35mm[/url]

Check out the specifications link.

[Morgan_Moore]

Mamiya 35mm

Check out the specifications link.
[a href=\"index.php?act=findpost&pid=131813\"][{POST_SNAPBACK}][/a]

not that rough then  

but with a P45 that would become 22 * 1.1 = 24 (.2)

S

[Mort54]

Mamiya 35mm

Check out the specifications link.
[a href=\"index.php?act=findpost&pid=131813\"][{POST_SNAPBACK}][/a]

As Morgan indicated in his post, the spec value of 22 ignores the digital back crop factor. 24mm equivalent is the correct value for the P45.

[etrump]

As Morgan indicated in his post, the spec value of 22 ignores the digital back crop factor. 24mm equivalent is the correct value for the P45.
[a href=\"index.php?act=findpost&pid=131824\"][{POST_SNAPBACK}][/a]

If you look at the first chart it does show 24mm for the P45.



Am I missing something?

[Morgan_Moore]

If you look at the first chart it does show 24mm for the P45.



Am I missing something?
[a href=\"index.php?act=findpost&pid=131839\"][{POST_SNAPBACK}][/a]

but the same row 35mm for an APS

Am I missing something? (!)

S

[etrump]

but the same row 35mm for an APS

Am I missing something? (!)

S
[a href=\"index.php?act=findpost&pid=131892\"][{POST_SNAPBACK}][/a]

Look at the line comparing 35mm MF lens:

On full frame MF film the field of view is similar to a full frame 35mm camera using a 22mm lens.  So if you look the the mamiya viewfinder with this lens it is very similar to dialing in 22mm on the 17-40L canon lens on a 5d.

Since the P45 crops at 1.1 then multiple the 22mm by 1.1 gives you 24.2mm.  So if you take a shot with the canon 5d at 24mm it looks similar to the P45 with the 35mm MF lens.  Increase the crop to 1.3 of the P30 and it looks like the canon at 29mm.

Since the 30D is a 1.6 crop if you had a 22mm lens it would look like 35mm focal length on the canon 5d.  

Obviously wide angle is not a reason to go to MF digital backs especially the cheaper 1.3 crop sensors.

[eronald]

Whyat is not apparent here is the depth of field variation, which we all know exists with cropped sensors. So what is the "equivalent 35mm camera F-stop" of an 80 mm F2.8 lens on a P30 ?

Edmund

[etrump]

Whyat is not apparent here is the depth of field variation, which we all know exists with cropped sensors. So what is the "equivalent 35mm camera F-stop" of an 80 mm F2.8 lens on a P30 ?

Edmund
[{POST_SNAPBACK}][/a]

Obviously that is much more involved.  You might want to take a look at:

[a href=\"http://www.kekus.com/software/fovcalculator.html]FOV Calculator[/url]

It would be interesting to expand the focal length spreadsheet with some info from this program.  I have played with it and think it is reasonably accurate.