My Stupid Question of 2009 !!!

[gordonb]

Will someone explain the crop factor to me please!! I see a of a pictire then someone says to crop it 100%. So they repost and it's just blown up to emphasize a certain area. Is there a rule of thumb to go by or is it just a yuppie word to enlarge an area...I used to think I was fairly intelligent until I ran into this thing called CROP. There has to be a better word or way?

Gordon

( I can hardly wait till viagra starts using it in commercials ...)

[440roadrunner]

It's not "blown up." What this means is it is a ONE HUNDRED PERCENT SIZED crop out of an original photo. THEN (typically) the poster will show the original frame UNDERSIZED, to show the framing of the shot, so that "we" don't have to download a huge gigantic file of the original frame. It is, simply, a way to show important details of a shot without having to load the server with huge files.

[advaitin]

Think of it like this. In your editing program you can view your image full size (most likely). That is 100 percent--the pixel level, basically. In your cropping you slice out that same portion from your overall image to present what you believe to be (a) sharp (b) messed up (c) interesting or (d) say, what is this?

[gordonb]

It's not "blown up." What this means is it is a ONE HUNDRED PERCENT SIZED crop out of an original photo. THEN (typically) the poster will show the original frame UNDERSIZED, to show the framing of the shot, so that "we" don't have to download a huge gigantic file of the original frame. It is, simply, a way to show important details of a shot without having to load the server with huge files.

Thanks for the reply 440roadrunner and advaintin
So it's been enlarged to allow us to view a n area without making the file to big to post.
I'm not being rude but it's just been enlarged so why call it cropped. Just say you enlarged it to emphasize a certain area. I honestly do not want anyone to think I am being rude or stupid I just do not under stand Why. So when I post a picture please tell me to enlarge a certain area and I will ..

Gordon

[duane0524]

Thanks for the reply 440roadrunner and advaintin
So it's been enlarged to allow us to view a n area without making the file to big to post.
I'm not being rude but it's just been enlarged so why call it cropped. Just say you enlarged it to emphasize a certain area. I honestly do not want anyone to think I am being rude or stupid I just do not under stand Why. So when I post a picture please tell me to enlarge a certain area and I will ..

Gordon

They have just "cropped" a section of the image viewed at 100% or actual pixel size. Nothing has been enlarged, it is merely showing the area of the picture that they want to show at is actual size.

Hope that helps.

[advaitin]

Thanks for the reply 440roadrunner and advaintin
So it's been enlarged to allow us to view a n area without making the file to big to post.
I'm not being rude but it's just been enlarged so why call it cropped. Just say you enlarged it to emphasize a certain area. I honestly do not want anyone to think I am being rude or stupid I just do not under stand Why. So when I post a picture please tell me to enlarge a certain area and I will ..

Gordon

Any time you select a portion of a total image to print or post, it is called cropping, regardless of the final size. The term goes back a long way into the early years of of wet photography when a pair of scissors was used to cut out , or "crop", a section of print for examination. When we darken an area within a print, we call it "burning in" because in the old days we continued to expose light to portions of the print to achieve that effect. Likewise, holding back light was called "dodging".

These terms are still used because they have become shorthand for the effect we get rather than the exact method that produces the effect.

[EnglishBob]

a 100% crop has not been enlarged, it is at it's natural pixel size. The typical monitor will display an image of less than 2 MP, a lot less than 1 MP. So to show an image in it's proper framing, the picture is reduced a LOT.

To illustrate a cameras detail or natural images, people will get the image in photoshop, set the view to full size or 100%, and then slice a small section out with the crop tool. This sample section will be small enough in dimensions to fit on the screen without being reduced in size, so can be shown at 100% size.

[gordonb]

a 100% crop has not been enlarged, it is at it's natural pixel size. The typical monitor will display an image of less than 2 MP, a lot less than 1 MP. So to show an image in it's proper framing, the picture is reduced a LOT.

To illustrate a cameras detail or natural images, people will get the image in photoshop, set the view to full size or 100%, and then slice a small section out with the crop tool. This sample section will be small enough in dimensions to fit on the screen without being reduced in size, so can be shown at 100% size.


Thanks for the reply.

I am still confused. But I spend cropped at 80% most of the time.

HAPPY NEW YEAR !!!

Gordon

[oaktree]

The thing that confuses me is the "mathematics" :(

A 50% crop shows 50% of the entire photo. A 75% crop shows 25% of the entire photo. A 99% crop "should" show 1% of the entire photo.

So, a 100% crop "should" show NONE of the photo :)

Or is it just the smallest section of the entire photo that your PP program will allow you to see? So a 100% crop could be different depending on the program you're using?

[advaitin]

The thing that confuses me is the "mathematics" :(

A 50% crop shows 50% of the entire photo. A 75% crop shows 25% of the entire photo. A 99% crop "should" show 1% of the entire photo.

So, a 100% crop "should" show NONE of the photo :)

Or is it just the smallest section of the entire photo that your PP program will allow you to see? So a 100% crop could be different depending on the program you're using?

Personally I think you are right. Like our custom of using wet photo terms, we've blended in 100 percent pixel peeping to cropping. If you were to use traditional terms--and I often do with comments-- I say I cropped 25 percent of the image (off). In the case of what we call 100 percent crops, while they are crops--they are 100 percent at the pixel level--but actually about a ten percent crop of the picture area.

But it is becoming custom, no matter how inaccurate it may be as description.

[e02937]

Imagine paper...

100% crop = taking the entire piece of paper and cutting out a square from it. That square is just a piece of the original picture but is still 100% of its original size. No enlarging or resizing has been done.

[advaitin]

Imagine paper...

100% crop = taking the entire piece of paper and cutting out a square from it. That square is just a piece of the original picture but is still 100% of its original size. No enlarging or resizing has been done.

See, there is always someone who doesn't get it. LOL

[e02937]

What do you mean? That is a 100% crop at least insofar as the term is constantly used here and on many photography forums.

[gordonb]

Thanks for all the input.
I look at it the same way I looked at the inverse square law when I had to take Nuclear Physics.

I am confused but still use it.

Thanks Everyone
HAPPY NEW YEAR

Gordon

[advaitin]

What do you mean? That is a 100% crop at least insofar as the term is constantly used here and on many photography forums.

You weren't joking? See English Bob's explanation.

[e02937]

No I was not joking, but, my explanation and that of Bob's are the same.

I was just using the example of paper to make it easier to understand.

[Wilt]

The thing that confuses me is the "mathematics" :(

A 50% crop shows 50% of the entire photo. A 75% crop shows 25% of the entire photo. A 99% crop "should" show 1% of the entire photo.

So, a 100% crop "should" show NONE of the photo :)

Or is it just the smallest section of the entire photo that your PP program will allow you to see? So a 100% crop could be different depending on the program you're using?

Gawd I hate how digital has confused photographers more than it should!

'100%' simply means that 1 pixel in image = 1 pixel on computer display... so that there is no need for the computer to 'shrink to fit' the full image into the available space. 50% means that every other pixel has to not be shown on the monitor, so that it fits.

[sued5320]

Should be called ZOOM-N-CROP.

Zoom to xx% and then crop out a section - usually that will fit within a viewable monitor area without having to slide the image up/down/left/right.

[oaktree]

Gawd I hate how digital has confused photographers more than it should!

'100%' simply means that 1 pixel in image = 1 pixel on computer display... so that there is no need for the computer to 'shrink to fit' the full image into the available space. 50% means that every other pixel has to not be shown on the monitor, so that it fits.

So if you had a HUGE monitor that could display the entire image 1:1, it would be 100% cropped ;) Just kidding.

I think I know what you mean. You display a smaller portion of the total image until you get to the 1 pixel in image = 1 pixel on the computer display. When you get to this point = 100% crop.

[sued5320]

It's really not 100% crop until you actually take out a section of the original image.

If you only display a smaller portion of the total image until you get the 1 pixel = 1 pixel, you haven't cropped anything else out.

[DAMphyne]

I hate to bring up the old days but "Crop" is not a new term specific to digital.
In darkroom terms, crop means to discard unwanted parts of the image to achieve the size and content of the photograph being made. You "Crop off " what you don't want.
100% crop means to throw away all but what will display in a set size, ex. 1000pixels X 600pixels.

[oaktree]

It's really not 100% crop until you actually take out a section of the original image.

If you only display a smaller portion of the total image until you get the 1 pixel = 1 pixel, you haven't cropped anything else out.

Added to what Wilt said:

(1) 100% crop would never be used in the "film days" because it would mean NO PICTURE.

(2) When used in the digital era, we do crop as we PP but this should be calculated on the basis of (MP of original image - MP of cropped image)/(MP of original image) x 100%. So if your original image is 21 MP and you cropped image is 10 MP, your "crop" would be (21 - 10)/21 x 100% = 52%.

(3) Stop using 100% crop! Say instead: show me a maximum digital zoom (or MDZ) so I can decide if your lens is crap.

Problem solved :)

[gordonb]

I am glad that I ask this stupid question (no such thing as a stupid Question. Right?) I felt I would recieve some inteligent answers and I did. Thank You All Very Much.

BUT! After reading all the posts carefully I still think when you do a crop your actually zooming in on an area of a picture and creating a seperate picture from the original.
I hope I have Not Offended anyone and if I did You will Survive.

I want to wish everyone a HAPPY NEW YEAR and keep the the pixelizations of images coming. This is my second favorite forum.

Gordon
US Navy Retired

Gordon