100% crop = ??? full frame size ???

ef2 wrote in post #7524584
The flagship 1Ds is nowhere to be found.

On one hand, maybe since it's a FF, he doesn't need that in his post. But on the other, the 5Ds are listed...

basroil wrote in post #7525241
No stupid questions, but sorry to say this is a stupid comment. As others and myself have said, you can print any size, so stating that is meaningless. Additionally, enlargement is function of sensor size in the non-resolution limited case (which most prints follow perfectly, only magazine prints or other specialty things are resolution limited even with 12mp images).

And if you didn't know, you can easily do most of the calculations you want to do according to that post in your head, and if you find that too slow, you can use a simple calculator. No point in putting tables up, it'd be like having multiplication tables for all numbers between 1 and 3000. I wouldn't even want to see that, and 99% of the values would be meaningless to me.

I guess I need to clarify myself...

I don't know the size of images from different models when displayed at 100%, so I asked a simple question that seems to be too confusing...

I'm not interested in the print size listed in the image size at the 100% view...or how big or small a print can be made...only how big the display would be if printed...

If that is too confusing, then forget the printing part...

On the 30D I know that the same image would be 32x48 @ 72 dpi or 6.6x10 @ 350dpi...but if I measured the 350dpi display it would be 32x48 so I guess I'm interested in the DISPLAY size not the print size...that is, what size monitor would be required to display the entire image of a 100% crop on the other models...

...given models' different size sensor, i.e. number of pixels, the size of the sensor itself, I wondered if there is any significant difference among them.

Maybe that is clearer...if each person with the model listed replied with the answer I'd add it to the list...
Again, thanks to all who reply...

and I did add the 1Ds....if another is missing just let me know and I'll add it...

kitacanon wrote in post #7525596
I'm not interested in the print size listed [...] ...only how big the display would be if printed...

That depends on the print resolution. There is no standard, but 300 dpi is very common.

That depends on the display resolution. There are several standards, of which 72 ppi is probably most common.

Your image size in inches will be the total sensor resolution expressed in terms of height x width in pixels divided by the pixels per inch (PPI) of your monitor.

Different monitors have different PPI (function of resolution and physical size) so you can't have a one size fits all approach. Imagine a 17" laptop screen. It might have a resolution of 1920x1200, as mine does, or perhaps 1650x1050 or perhaps 1440x900. Each one clearly will have a different PPI. The old standard was 72 PPI. These days it could be all sorts of values but normally higher than 72.

My 17" laptop is 14.5 inches across. The PPI = 1920/14.5 = 132.
If my resolution was 1650x1050 the PPI would be 1650/14.5 = 114.
If my resolution was 1440x900 the PPI would be 1440/14.5 = 99.

If you want to go old school and consider a 15" 1024x768 monitor the PPI would be 1024/12 = 85. A 17" 1024x768 monitor would be 75.

My 40" HDTV, with a resolution of 1920 x 1080, has a PPI of 54.

Picking 100 DPI seems as good as any and keeps the maths really simple. there is no need for any table. Just divide the pixel dimensions of your image by 100 and you have your dimensions in inches. Easy.

50D = 4752 x 3168 pixels. At 100 PPI the size would be 48" x 32".
40D = 3888 x 2592 pixels. At 100 PPI the size would be 39" x 26".

If you want high quality printing at 300 PPI then a 50D gives you approx 16" x 11" and a 40D gives you approx 13" x 9".

kitacanon wrote in post #7525596
I guess I need to clarify myself...

I don't know the size of images from different models when displayed at 100%, so I asked a simple question that seems to be too confusing...

I'm not interested in the print size listed in the image size at the 100% view...or how big or small a print can be made...only how big the display would be if printed...

The fact is that there is no single answer for your question because, as illustrated above, there's no single definition for the resolution of computer displays.

The only numbers that count for you is the combination of the definition of YOUR computer display and the pixel count of the images from YOUR camera.

Anybody else interested in the same calculation would have to use those two numbers for THEIR equipment, as both are likely to be different from yours.

tzalman wrote in post #7524151
There is no single print size for any camera unless you specify two conditions:
1.No resampling.
2. A given ppi.

Substitute "monitor display" for "print" in my previous answer and it still applies.

kitacanon wrote in post #7525596
I guess I need to clarify myself...

I don't know the size of images from different models when displayed at 100%, so I asked a simple question that seems to be too confusing...

I'm not interested in the print size listed in the image size at the 100% view...or how big or small a print can be made...only how big the display would be if printed...

If that is too confusing, then forget the printing part...

On the 30D I know that the same image would be 32x48 @ 72 dpi or 6.6x10 @ 350dpi...but if I measured the 350dpi display it would be 32x48 so I guess I'm interested in the DISPLAY size not the print size...that is, what size monitor would be required to display the entire image of a 100% crop on the other models...

...given models' different size sensor, i.e. number of pixels, the size of the sensor itself, I wondered if there is any significant difference among them.

Maybe that is clearer...if each person with the model listed replied with the answer I'd add it to the list...
Again, thanks to all who reply...

and I did add the 1Ds....if another is missing just let me know and I'll add it...

Sorry, but you are still not making any sense. All you are looking at is how many MP there are. Simply look at that number and you know exactly what you want to know. There are only three important features when discussing sensors in terms of display or printing. That is sensor size, pixel density, and bit depth (which will likely never come into play as no cheaper monitors can properly display 16 bit images, most do only 8 per channel). All other results are derived from these three (generally just the first two actually) from simple math (multiplication, division). There is no point in listing everything else since all you are doing is repeating the same information a million times over.

kitacanon wrote in post #7525596
so I asked a simple question that seems to be too confusing...

No, you asked a question that has no answer (or to be more accurate has a very large number of answers, all different and all correct ..... for someone).

Your image size, that you can compare between cameras, is measured in pixels. That information is very easy to look up for any camera as it is one of the main specification points.

You cannot compare print or display sizes in inches because that involves a calculation to convert those pixel sizes into inches. Such a calculation depends on user choice as to how many pixels per inch (actually dots per inch but lets not confuse things) you choose to print at, or how many pixels per inch you choose to display on your screen.

You can easily work out such things for yourself, by dividing your choice of dpi / ppi for printing and displaying into the image size in pixels. If you have an image 4500 x 3000 pixels and want to print at 300 dpi, you would get a 15" x 10" print.

You can't just drop that into a table though, stating that that camera 'gives' 15" x 10" prints, as somebody else may choose to use 150 dpi and produce a 30" x 20" print, equally somebody could print a 7.5" x 5" print at 600 dpi should they wish.

The same is true for monitor display, you can make images bigger or smaller on your monitor by choosing a different display resolution. So, again, you can't give a physical dimension in inches that will be 'right'.

Nobody can give you the information you are asking for. Just do the math according to your choice of print / display resolutions. Any of those cameras will produce 6" x 4" prints or prints that will fill a 30 foot billboard. Somewhere in there you should be able to find the print size you are after.

kitacanon wrote in post #7525596
I guess I need to clarify myself...

I don't know the size of images from different models when displayed at 100%, so I asked a simple question that seems to be too confusing...

I'm not interested in the print size listed in the image size at the 100% view...or how big or small a print can be made...only how big the display would be if printed...

I already posted the formula for you. All you have to do is use it. It calculates exactly what you asked for earlier in this thread: if you're looking at an image at 100% magnification (pixel level) on a monitor, assuming that view is equivalent to the corresponding crop of a print how big would that print be.

What? After I spent all that time laboring to derive a formula for you? Ingrate!

Physical sensor size has nothing to do with how big you can theoretically print; only sensor resolution (number of pixels) matter. There's the issue of pixel quality that nobody has been able to quantify, but assuming an easy scene that wouldn't tax any modern sensor (e.g. bright daylight), image resolution is what matters. In other words, you'd be able to print just as large from an 8MP 20D image as you would from an 8MP 1DII image for instance, even though they have different physical sensor sizes (20D is 1.6x, 1DII is 1.3x).

Thank you all for your replies...this all came to my mind when I'd read someone's advice to view a 100% crop from a distance rather than peep at pixels from 12"...while reading about the optimal viewing distance of different size HD TV screens (apparently it is 1.3x to 1.5x the diagonal) and wondered what in fact would be the recommended viewing distance of the full frame of the 100% crop...but to do that I'd need to know the measurements of the full frame...
If displays vary from a 72ppi standard (throwing "standard" itself into question) then I'd agree it is not reasonable to create a chart as I'd hoped, to make clear (ha) just how big those 100% images would be and thus how far one should view them...
Oh well....

The 72 ppi "standard" has been obsolete for twenty years, its original intent was to allow CRT TV sets to be used as monitors, and has persisted as an urban myth. You will still see posters on these forums falsely advising others that any image posted on the web has to be 72 dpi.

List of displays by pixel density
From Wikipedia, the free encyclopedia
Standard-aspect Display

Diagonal Pixels PPI
17" 1024x768 75
19" 1024x768 67
21" 1024x768 61
24" 1024x768 53
25" 1024x768 51

17" 1280x1024 96
19" 1280x1024 86
21" 1280x1024 78
24" 1280x1024 68
25" 1280x1024 66

Wide-aspect Display

Diagonal Pixels PPI
19" 1440x900 89
20.1" 1680x1050 99
21.5" 1920x1080 102
22" 1680x1050 90
23" 1920x1200 98
24" 1920x1200 94
27" 1920x1200 84
30" 2560x1600 101

Notebook Display

Diagonal Pixels PPI
7" 720x480 124
8.9" 1024x600 133

12.1" 1024x768 105
12.1" 1280x800 125
13.3" 1280x800 113
14.1" 1280x800 107
15.4" 1280x800 95

11.1" 1366x768 141

12.1" 1440x900 140
14.1" 1440x900 120
15.4" 1440x900 110
17" 1440x900 100
12.1" 1400x1050 144
14.1" 1400x1050 124
15" 1400x1050 117

14.1" 1600x1200 142
15.4" 1680x1050 129
17" 1680x1050 117

16" 1920x1080 137
18.4" 1920x1080 120

15.4" 1920x1200 147
17" 1920x1200 133

tzalman wrote in post #7532580
List of displays by pixel density
From Wikipedia, the free encyclopedia

Could you please post a link to this info? That would be handy to have (though for other reasons than the PPI part).

Thanks.

http://en.wikipedia.or​g/wiki/List_of_Device_​PPI

The last 2 charts suggest why it's impossible to make the chart....
still...
...since so many have posted their advice but did not answer my request, and as each monitor's specifications varies, I still would like to ask, if it would not be an inconvenience, a few people to post their 100% crop's full frame size, just to have an idea how they vary...
Again, thank you...

50D : 88" x 59" on my HDTV; 36" x 24" on my 17" laptop; 38" x 25" on my 12.1" laptop.