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09-03-2018, 07:10 PM   #76
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I thought mf (ones in 645z and 50s) is around 30% larger than ff.

FF is 36x24...(864sqmm)...crop MF is 44x33(1452)...to be accurate its 68% larger.

09-03-2018, 09:00 PM - 2 Likes   #77
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QuoteOriginally posted by surfar Quote
I thought mf (ones in 645z and 50s) is around 30% larger than ff.

FF is 36x24...(864sqmm)...crop MF is 44x33(1452)...to be accurate its 68% larger.
You need to be careful about whether you're talking linear or area measurements.

Linear measurements are usually compared by the diagonal of the sensor. FF=43.3mm, crop MF=55mm, so the ratio is 1.27. 27% larger.

Yes, the area is 68% larger.
09-03-2018, 09:05 PM   #78
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QuoteOriginally posted by surfar Quote
FF is 36x24...(864sqmm)...crop MF is 44x33(1452)...to be accurate its 68% larger.
59.5% larger

1452mm2 x 0.595 =864mm2


The area difference really boils down to the final image ratio, if you are to use 4x3 then 645 has a much larger area than FF and if you are using 16-9 or 3x2 then the size difference is much smaller
09-03-2018, 09:22 PM   #79
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QuoteOriginally posted by Ian Stuart Forsyth Quote
59.5% larger

1452mm2 x 0.595 =864mm2


The area difference really boils down to the final image ratio, if you are to use 4x3 then 645 has a much larger area than FF and if you are using 16-9 or 3x2 then the size difference is much smaller
Your math is wrong. When you say something is some percent larger than something else, the smaller one is the base. 864 + (68% * 864) = 1452.

09-03-2018, 09:24 PM   #80
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QuoteOriginally posted by Mark Ransom Quote
Your math is wrong. When you say something is some percent larger than something else, the smaller one is the base. 864 + (68% * 864) = 1452.
Ya beat me to my correction you are correct
09-03-2018, 09:29 PM   #81
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59.5% larger

The FF is the crop factor one...determining how much larger means the bigger dimension must be divided by the smaller.

The sensors are rounded to the closest full number as well...i cant be bothered getting the exact dimensions...

But MF crop sensor has around 70% more area to catch light....Thats a simple explanation.
09-04-2018, 11:07 AM - 1 Like   #82
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I was told there would be no math.
09-04-2018, 11:49 AM   #83
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QuoteOriginally posted by surfar Quote
59.5% larger

The FF is the crop factor one...determining how much larger means the bigger dimension must be divided by the smaller.

The sensors are rounded to the closest full number as well...i cant be bothered getting the exact dimensions...

But MF crop sensor has around 70% more area to catch light....Thats a simple explanation.
You need fairly accurate numbers - otherwise you're calculating with garbage,

If something has 70% more area, then its area is 1.7 times larger.
If area is 1.7 times as large, the linear dimensions are sqrt(1.7) = 1.3 times as large, or 30% larger.

On the other hand, if length and width is each 59.9% larger, then they are 1.599 times as large,
and the area would be (1.599)(1.599) = 2.5568 times larger, or 155.68% larger.

The numbers in your post are not even close to being consistent.

09-04-2018, 01:32 PM   #84
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QuoteOriginally posted by reh321 Quote
You need fairly accurate numbers - otherwise you're calculating with garbage,

If something has 70% more area, then its area is 1.7 times larger.
If area is 1.7 times as large, the linear dimensions are sqrt(1.7) = 1.3 times as large, or 30% larger.

On the other hand, if length and width is each 59.9% larger, then they are 1.599 times as large,
and the area would be (1.599)(1.599) = 2.5568 times larger, or 155.68% larger.

The numbers in your post are not even close to being consistent.
They're not consistent because you're assuming the aspect ratios are the same. FF is 3:2 while MF is 4:3. That's why you compare the diagonals instead of the width or height for the linear measurement. Of course for area measurements the aspect ratio doesn't matter.
09-04-2018, 03:26 PM   #85
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QuoteOriginally posted by reh321 Quote
The numbers in your post are not even close to being consistent.
Oh, well...i'll put some photos up ...my MF next to my FF,hows that?...You wanta do the same?
09-04-2018, 04:12 PM - 1 Like   #86
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Okay, so theres math. I'll take a stab at it. My findings will be in agreement and disagreement with previous posts. All measurments rounded to the nearest millimeter. Fuji's medium format sensor: 44mm x 33mm (4:3 aspect ratio). Full frame sensor: 36mm x 24mm (3:2 aspect ratio). It Pythagoras was not wrong, their respective diagonal measurements are 55mm and 43mm. The medium format sensor has a 28% longer diagonal- a useful metric for calculating crop factor. It's 22% wider on the x axis, and 37.5% taller on the y. What really counts for gauging image quality between the two, imo, is overall surface area. At least insofar as image quality is influenced by sensor size. The MF sensor has an area of 1452 square millimeters, vs. 864 square millimeters for the full frame sensor. The medium format sensor is 68% larger.

Last edited by vZwicky; 09-04-2018 at 04:35 PM.
09-04-2018, 04:18 PM   #87
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QuoteOriginally posted by vZwicky Quote
Okay, so theres math. I'll take a stab at it. My findings will be in agreement and disagreement with previous posts. All measurments rounded to the nearest millimeter. Fuji's medium format sensor: 44mm x 33mm (4:3 aspect ratio). Full frame sensor: 36mm x 24mm (3:2 aspect ratio). It Pythagoras was not wrong, there respective diagonal measurements are 55mm and 43mm. The medium format sensor has a 23% longer diagonal. It's 22% wider on the x axis, and 37.5% taller on the y. What counts, imo, is overall surface area. The MF sensor has an area of 1452 square millimeters, vs. 864 square millimeters for the full frame sensor. The medium format sensor is 68% larger.
Only one thing I disagree with, and I think it's probably a typo: 55/43 = 1.279, meaning 28% longer diagonal (not 23%).
09-04-2018, 04:26 PM   #88
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QuoteOriginally posted by Mark Ransom Quote
Only one thing I disagree with, and I think it's probably a typo: 55/43 = 1.279, meaning 28% longer diagonal (not 23%).
Keen eye. Thanks, Mark Ransom. A typo it is. Correcting that now.
09-04-2018, 04:42 PM   #89
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QuoteOriginally posted by vZwicky Quote
The MF sensor has an area of 1452 square millimeters, vs. 864 square millimeters for the full frame sensor. The medium format sensor is 68% larger.
Somebody else said that?
09-04-2018, 06:03 PM   #90
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QuoteOriginally posted by surfar Quote
Somebody else said that?
If I'm not mistaken, you did, surfar. I didn't want to weigh in until I crunched the numbers myself.
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