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Author Topic: Trying to draw viewfinder sizes on screen  (Read 901 times)

T-RonX

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Trying to draw viewfinder sizes on screen
« on: March 28, 2013, 11:05:13 AM »
Hi,

I am trying to make a little tool for myself to compare viewfinder sizes. I do get some results but the rectangles seem to be a bit small I think. Probably interpreting some values wrong. Can someone please have a look?

The colors in red are the 6D's sensor size, magnification, viewfinder coverage and aspect ratio respectively.

magni = ((35,8 mm * 23,9 mm) = 855,62 mm2) * .71x = 607,4902 mm2
surface = (magni * 97%) = 589,265494 mm2
edge = sqrt(surface) = 24,274791327630398396804364790437 mm) * 2 = 48,549582655260796793608729580875 mm
aspec_part = edge / (3 + 2) = 9,7099165310521593587217459161749 mm
width = aspec_part * 3 = 29,129749593156478076165237748525 mm
height = aspec_part * 2 = 19,41983306210431871744349183235 mm
width_px =(width * 0,0393700787) = 1,1468405339938635232734500043636 inch * 72 dpi = 83px
height_px = (height * 0,0393700787) = 0,76456035599590901551563333624242 inch * 72 dpi = 55px

Below are the results I get.

Thanks,
Ron
« Last Edit: March 28, 2013, 01:26:53 PM by T-RonX »
EOS 6D - EF 24-70mm f/2.8L II USM - EF 100mm f/2.8L Macro IS USM - EF 50mm f/1.4 USM - Manfrotto 055CX3 CF Tripod - Manfrotto 410 Geared Head - Speedlite 430EX II

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Trying to draw viewfinder sizes on screen
« on: March 28, 2013, 11:05:13 AM »

jcollett

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Re: Trying to draw viewfinder sizes on screen
« Reply #1 on: March 28, 2013, 12:21:57 PM »
They look small probably due to the same reason big screen TVs look smaller in a big box store like Costco or Sam's Club.  The boxes are on a large white area, so they appear smaller.  Remember, the actual finders are only about a centimeter away from your eye instead of a few decimeters or feet.

sandymandy

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Re: Trying to draw viewfinder sizes on screen
« Reply #2 on: March 28, 2013, 12:52:09 PM »
I wanna see the 1100D one, please

T-RonX

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Re: Trying to draw viewfinder sizes on screen
« Reply #3 on: March 28, 2013, 01:02:35 PM »
There you go. If anyone can tell me these calculations are correct I could make a public tool out of this.
EOS 6D - EF 24-70mm f/2.8L II USM - EF 100mm f/2.8L Macro IS USM - EF 50mm f/1.4 USM - Manfrotto 055CX3 CF Tripod - Manfrotto 410 Geared Head - Speedlite 430EX II

T-RonX

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Re: Trying to draw viewfinder sizes on screen
« Reply #4 on: March 28, 2013, 01:20:15 PM »
Ok I found a flaw. I assumed my Dell U2410 had 72 dpi, which I guess is from the old analog days, but it actually has 94 dpi. But I'm still not sure if the calculations are correct at all. Anyone?

edit:
update result pic with dpi
« Last Edit: March 28, 2013, 01:27:28 PM by T-RonX »
EOS 6D - EF 24-70mm f/2.8L II USM - EF 100mm f/2.8L Macro IS USM - EF 50mm f/1.4 USM - Manfrotto 055CX3 CF Tripod - Manfrotto 410 Geared Head - Speedlite 430EX II

Leejo

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Re: Trying to draw viewfinder sizes on screen
« Reply #5 on: March 28, 2013, 01:57:13 PM »
The basic width and height appear reasonable in cm (20 by 30 mm).
(without a camera at hand)
The problem appears to be in the representation after that...
Canon 7D

hsbn

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Re: Trying to draw viewfinder sizes on screen
« Reply #6 on: March 28, 2013, 02:06:19 PM »
You made the math look too complicated.
Take the 6D for example, its sensor size is: 35.8mm x 23.9mm
The viewfinder is 0.71x magnification and 97%
So
96%x(35.8mm x 0.71) =24.655mm = 0.971 inch x 96 ppi = 93 pixel
96%x(23.9mm x 0.71) =16.459mm = 0.648 inch x 96 ppi = 62 pixel
Most monitor out there got 96ppi.

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Re: Trying to draw viewfinder sizes on screen
« Reply #6 on: March 28, 2013, 02:06:19 PM »

T-RonX

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Re: Trying to draw viewfinder sizes on screen
« Reply #7 on: March 28, 2013, 02:06:31 PM »
I wonder if I calculate the magnification right. Now I'm taking 71% of the total sensor surface. If I try to take 71% of each side of the sensor and then calculate the surface I end up with a tad smaller rectangle.
« Last Edit: March 28, 2013, 02:08:22 PM by T-RonX »
EOS 6D - EF 24-70mm f/2.8L II USM - EF 100mm f/2.8L Macro IS USM - EF 50mm f/1.4 USM - Manfrotto 055CX3 CF Tripod - Manfrotto 410 Geared Head - Speedlite 430EX II

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Re: Trying to draw viewfinder sizes on screen
« Reply #7 on: March 28, 2013, 02:06:31 PM »