Follow us on Twitter!
Follow us on Facebook!
 

Go Back   Pixtus - Photography Forum, Photographers, Photo Tips > Photography Information > Post Processing Central


Stupid Question of 2009 !!!!!

This is a discussion on Stupid Question of 2009 !!!!! within the Post Processing Central forums, part of the Photography Information category; I posted this question on aother forum and wanted to ask it here??? Gordon Will someone explain the crop factor ...

Reply
 
LinkBack Thread Tools Display Modes
  (#1) Old
Forum Regular
 
Chief's Avatar
 
Posts: 979
Join Date: Jan 2005
Location: L.O.E., New Mexico
Real First Name: Gordon
Camera: canon
Can Others Edit My Photos: Yes
iTrader Rating: 0

Likes Received LIKES Received: 15
Likes Given LIKES Given: 0
Stupid Question of 2009 !!!!! - 12-28-2009, 11:16 AM


I posted this question on aother forum and wanted to ask it here???

Gordon

Will someone explain the crop factor to me please!! I see a of a picture 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 ...)

---------------------------
KE5ILI
HAPPY TRAILS TO YOU, UNTIL WE MEET AGAIN !
WHOAA NELLI BELL !!!!
Reply With Quote
Sponsored Links

Premium Members do not see Google advertisements. SIGN UP today and help support our community.
  (#2) Old
Light Moderator
 
srwatters's Avatar
 
Posts: 11,926
Join Date: Jan 2005
Location: West Plano, Texas
Real First Name: Scott
Camera: Nikon D3 & Hasselblad H2
Can Others Edit My Photos: No
iTrader Rating: 16

Likes Received LIKES Received: 44
Likes Given LIKES Given: 10
12-28-2009, 11:35 AM


I think you're mixing metaphors here. IMHO the 'crop factor' refers to the size of the sensor in relation to a standard size. i.e. for 35mm format DSLR bodies that would be in reference to the 24x36mm standard size for film. Nikon's crop sensor in the D300 is a 1.5x crop factor while the D700 is a 1x crop factor. In medium format bodies like my Hasselblad H2 that shoot 645, the standard size is that of 120 film which is 56x41.5mm. My PhaseOne P45 digital back has a sensor size of 49.1x36.8mm for a crop factor of 1.1.

If someone refers to a 100% crop, that typically means that they are not resizing the image, but taking the original pixels as shot and only displaying a portion of them. For example, the P45 shoots 7216x5412 pixels total. It is impossible to display all those pixels on any single monitor that I know of, so if you want to see the detail without resizing, I can take only a portion and 'crop' it so you still see the original pixels without having to scroll horizontally or vertically. Make sense?

---------------------------
Scott Watters
PoloDigital | Flickr | Pbase
Nikon | Hasselblad | Phase One | Hensel | Apple
Reply With Quote
  (#3) Old
Forum Regular
 
Chief's Avatar
 
Posts: 979
Join Date: Jan 2005
Location: L.O.E., New Mexico
Real First Name: Gordon
Camera: canon
Can Others Edit My Photos: Yes
iTrader Rating: 0

Likes Received LIKES Received: 15
Likes Given LIKES Given: 0
12-28-2009, 12:36 PM


Quote:
Originally Posted by srwatters View Post
I think you're mixing metaphors here. IMHO the 'crop factor' refers to the size of the sensor in relation to a standard size. i.e. for 35mm format DSLR bodies that would be in reference to the 24x36mm standard size for film. Nikon's crop sensor in the D300 is a 1.5x crop factor while the D700 is a 1x crop factor. In medium format bodies like my Hasselblad H2 that shoot 645, the standard size is that of 120 film which is 56x41.5mm. My PhaseOne P45 digital back has a sensor size of 49.1x36.8mm for a crop factor of 1.1.

If someone refers to a 100% crop, that typically means that they are not resizing the image, but taking the original pixels as shot and only displaying a portion of them. For example, the P45 shoots 7216x5412 pixels total. It is impossible to display all those pixels on any single monitor that I know of, so if you want to see the detail without resizing, I can take only a portion and 'crop' it so you still see the original pixels without having to scroll horizontally or vertically. Make sense?

Not really Scott ? But I'm working on it..Maybe it should be called Zoom or resize??

Happy New Year

Gordon

---------------------------
KE5ILI
HAPPY TRAILS TO YOU, UNTIL WE MEET AGAIN !
WHOAA NELLI BELL !!!!

Last edited by Chief; 12-28-2009 at 12:39 PM..
Reply With Quote
  (#4) Old
Light Moderator
 
srwatters's Avatar
 
Posts: 11,926
Join Date: Jan 2005
Location: West Plano, Texas
Real First Name: Scott
Camera: Nikon D3 & Hasselblad H2
Can Others Edit My Photos: No
iTrader Rating: 16

Likes Received LIKES Received: 44
Likes Given LIKES Given: 10
12-28-2009, 01:18 PM


To quote my favorite movie:
Inigo Montoya:"Let me explain... No there is too much. Let me sum up..."

Here is a web size image:


Here is the full size image as captured by my P45 digital back:
39MP Image Link

Here is a 100% crop of Lorie's eye:


If you overlay the crop on top of the full size image, you'll see the pixels are the same. That's the definition of a crop. It's just a portion of the full image versus a digital resizing (interpolation, the first image above) of the full image either larger or smaller.

---------------------------
Scott Watters
PoloDigital | Flickr | Pbase
Nikon | Hasselblad | Phase One | Hensel | Apple
Reply With Quote
  (#5) Old
Forum Regular
 
Chief's Avatar
 
Posts: 979
Join Date: Jan 2005
Location: L.O.E., New Mexico
Real First Name: Gordon
Camera: canon
Can Others Edit My Photos: Yes
iTrader Rating: 0

Likes Received LIKES Received: 15
Likes Given LIKES Given: 0
12-28-2009, 02:02 PM


Quote:
Originally Posted by srwatters View Post
To quote my favorite movie:
Inigo Montoya:"Let me explain... No there is too much. Let me sum up..."

Here is a web size image:


Here is the full size image as captured by my P45 digital back:
39MP Image Link

Here is a 100% crop of Lorie's eye:


If you overlay the crop on top of the full size image, you'll see the pixels are the same. That's the definition of a crop. It's just a portion of the full image versus a digital resizing (interpolation, the first image above) of the full image either larger or smaller.
I am having a light bulb moment Scott.

I cropped and area of a photo and that in essence creates a new picture of the original shot. It's just a way to ( zoom or resize ) an area of a shot creating a completely new picture at a magnified size. ( crap ) now I confused myself again, but I get the idea Scott.. Thanks

Where doed the % scale come into effect and why?

Gordon

---------------------------
KE5ILI
HAPPY TRAILS TO YOU, UNTIL WE MEET AGAIN !
WHOAA NELLI BELL !!!!
Reply With Quote
  (#6) Old
Light Moderator
 
srwatters's Avatar
 
Posts: 11,926
Join Date: Jan 2005
Location: West Plano, Texas
Real First Name: Scott
Camera: Nikon D3 & Hasselblad H2
Can Others Edit My Photos: No
iTrader Rating: 16

Likes Received LIKES Received: 44
Likes Given LIKES Given: 10
12-28-2009, 02:24 PM


Quote:
Originally Posted by Chief View Post
I am having a light bulb moment Scott.

I cropped and area of a photo and that in essence creates a new picture of the original shot. It's just a way to ( zoom or resize ) an area of a shot creating a completely new picture at a magnified size. ( crap ) now I confused myself again, but I get the idea Scott.. Thanks

Where doed the % scale come into effect and why?
If you simply crop an image, there is no resizing involved. Imagine you are simply throwing away some of the image but the part of the image you are keeping is completely unchanged. Another way to think about it is if you were to frame a print and use a mat smaller than the original photograph. You effectively have 'cropped' the print using the mat. In the digital world, cropping is the same thing except you can't remove the mat and still have the original.

The only percentage that makes sense with regard to a crop is 100%. Any other percentage would indicate that the image has been resized and either pixels have been compressed (when making a smaller image) or created (when making a larger one). If you use the crop tool in Photoshop, as long as you don't put any number in the resolution box and use only the height and width controls other than pixels, you will be performing a crop on the original pixels. Any other usage of that tool will create new image data.

---------------------------
Scott Watters
PoloDigital | Flickr | Pbase
Nikon | Hasselblad | Phase One | Hensel | Apple
Reply With Quote
  (#7) Old
You Can't Be Serious!!
 
bburton's Avatar
 
Posts: 6,470
Join Date: Jan 2005
Location: FORT WORTH, Texas
Real First Name: BRUCE
Camera: Whazat K23
Can Others Edit My Photos: Yes
iTrader Rating: 5

Likes Received LIKES Received: 27
Likes Given LIKES Given: 3
Exclamation Good On Ya - 12-28-2009, 04:03 PM


Good question; Excellent explanation and demonstration. Thanks to both of you.

---------------------------
Bruce Burton
My PhotoBlog
Reply With Quote
Reply

Tags
2009, question, stupid

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



Visit Our Sponsors
 

Google Sponsors

Premium Members do not see Google advertisements. SIGN UP today and help support our community.

Copyright ©2004 - 2011, Abel Longoria - www.Pixtus.com
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2012, vBulletin Solutions, Inc.