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MAMIYA 7 mathmatical lens shootout 80mm vs. 150mm
Old 08-07-2008   #1
lucky hack
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MAMIYA 7 mathmatical lens shootout 80mm vs. 150mm

Using the figures on the Mamiya website I did some geometry and it seems that at the minimum focusing distance you can get an even tighter shot with the 80mm by a foot !

Is that possible? Does anyone have any experience getting a tighter shot with the 80 than the 150 at the minimum focusing distance?

Also, if there is anyone out there who wants to check my math I would appreciate it...

yes, I know I'm nerd.....try not to hold it against me.

hoping this message finds you well -Ian
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Old 08-07-2008   #2
ferider
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The minimum distances you give (i found different specs when googeling but might be wrong) translate to a covered object dimension of 46.2cm (for the 80mm lens) and 66.0cm (for the 150mm lens) for 6cm in the film plane, at minimum focus of each lens. So the 80mm lens enlarges more by factor 1.43

Roland.

Last edited by ferider : 08-07-2008 at 16:15.
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Old 08-07-2008   #3
lucky hack
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The more I try to figure this out, the more I'm confused
My numbers don't jive with the Max Magnification specs...

The maximum magnification is .097x for the 80mm and .096x for the 150mm. Could it be that the 150mm lens is further away from the film plane than the 80mm? (like macro extenders)?

The more I learn, the less I know. Now I know what my dad meant when he talked about knowing just enough to be dangerous.


Thanks for your reply, -Ian
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Old 08-07-2008   #4
ferider
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Ian, I think your min. focus spec for the 80 might be wrong. Is this the same lens ?

http://www.epinions.com/Mamiya_80mm_...ay_~full_specs

With those 39in (you used 27.4) the two lenses have almost the same magnification. Close to .09 with my formulas above but not identical to the numbers that you quote.

Also not sure what they are using to measure the magnification. Maybe the effective focal lengths are a bit different ?

Roland.

PS:
Quote:
Originally Posted by lucky hack View Post
The more I try to figure this out, the more I'm confused
Sounds like Faust ....

Last edited by ferider : 08-07-2008 at 17:30.
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Old 08-07-2008   #5
john_s
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From the manual for the Mamiya 7:

80mm lens, closest focus 1m, magnification at closest distance is 0.097

150mm lens, closest focus 1.8m, magnification at closest distance is 0.096

So neither will give a tight head shot.
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Old 08-08-2008   #6
RObert Budding
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You will get a very different perspective with the 150, though.
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Old 08-08-2008   #7
lucky hack
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Roland,
here's the site http://www.mamiya.com/mamiya-7-ii-le...80mm-f4.0.html

what the Epinions website did was swap in the value for the 35mm equivalent by mistake. So I still don't quite understand but I guess that's alright too.

John,
(no tight headshot) I know, kind of a bummer. At least medium format negs are somewhat croppable...

Robert
Yeah, it's weird how it really changes the feeling, it places the viewer at a distance from the subject. Also I've found that when taking portraits, people are much more comfortable being photographed by a longer lens...

Thanks to all -Ian
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Old 08-09-2008   #8
bensyverson
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This is just not the camera for someone who wants to do tight headshots. The RB, RZ, C220 and C330 are all great for this purpose, since they all have bellows and can focus extremely close.
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