Approve the Cookies
This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and our Privacy Policy.
OK
Index  •   • New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Guest
New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Register to forums    Log in

 
FORUMS Canon Cameras, Lenses & Accessories Canon EOS Digital Cameras 
Thread started 11 Nov 2008 (Tuesday) 11:04
Search threadPrev/next
sponsored links
(this ad will go away when you log in as a registered member)

Sensor Crop - A heated debate!

 
Willie
Senior Member
959 posts
Likes: 2
Joined Feb 2004
     
Nov 12, 2008 12:33 |  #91

CyberDyneSystems wrote in post #6673128 (external link)
Member since 2004? You have access now.;) So you can stop debating crop factors.... :lol:

Cool, thank you. But what else am I supposed to do at work?




  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)
tonylong
...winded
Avatar
54,657 posts
Gallery: 60 photos
Likes: 544
Joined Sep 2007
Location: Vancouver, WA USA
     
Nov 12, 2008 12:39 |  #92

Bodog wrote in post #6673136 (external link)
Maybe I'm not asking the right question. Both lenses project an image circle on the sensor/film plane; the EF lens has a much larger circle, the EF-s smaller. Both have the same field of view, so both image circles should contain the same image. They don't. How can this be explained?

The image circle of the EF is larger, in other words projecting a wider field of view that covers a full frame sensor, the EF-S projects a smaller circle/field of view that covers a crop sensor. The field of view on the crop sensor is the same no matter which lens you use, though.


Tony
Two Canon cameras (5DC, 30D), three Canon lenses (24-105, 100-400, 100mm macro)
Tony Long Photos on PBase (external link)
Wildlife project pics here (external link), Biking Photog shoots here (external link), "Suburbia" project here (external link)! Mount St. Helens, Mount Hood pics here (external link)

  
  LOG IN TO REPLY
Willie
Senior Member
959 posts
Likes: 2
Joined Feb 2004
     
Nov 12, 2008 12:40 |  #93

pieq314 wrote in post #6673235 (external link)
Crop has nothing to do with reach (I am sure this has been pointed out after so many pages), because you can always crop a photo in post processing. In other words, you can crop a 5D photo to a 2X crop. Does that cropping increase the 5D's reach?

Pixel density is the only thing that matters in reach. A full frame with the same pixel density will have the same reach as a 4/3 camera (the full frame just gives you more freedom in cropping).

I know that crop has nothing to do with reach, if you are willing to crop a FF. My post said that if you don't want to crop, then the crop camera will have more reach. If I shoot with a 200mm on my crop camera and you also shoot with 200mm on FF, and if you don't have the time or want to crop all 300 hundred or whatever photos you took at the sporting event, then my images will have more "reach". That's all I said. It's a matter of convenience for me.




  
  LOG IN TO REPLY
imageswest
Senior Member
516 posts
Gallery: 2 photos
Likes: 27
Joined Apr 2006
Location: Gabriola Island, BC
     
Nov 12, 2008 12:44 as a reply to  @ Willie's post |  #94

My 5D gets crop on the sensor all the time... sometimes it gets so bad I have to send it in to Canon to have it cleaned. ;)


Cliff LeSergent
Images West Photography
www.imageswest.ca (external link)

  
  LOG IN TO REPLY
SkipD
Cream of the Crop
Avatar
20,476 posts
Likes: 158
Joined Dec 2002
Location: Southeastern WI, USA
     
Nov 12, 2008 12:46 |  #95

Bodog wrote in post #6673136 (external link)
Maybe I'm not asking the right question. Both lenses project an image circle on the sensor/film plane; the EF lens has a much larger circle, the EF-s smaller. Both have the same field of view, so both image circles should contain the same image. They don't. How can this be explained?

... Both have the same field of view on the APS-C sensor. Does it matter that part of the image projected by an EF lens is wasted in the APS-C camera? Not at all.

If you managed to put both EF and EF-S lenses of the same focal length on a 35mm film camera (or a so-called "full-frame" DSLR), the image projected by the EF lens will fully cover the film frame or sensor but the EF-S lens (modified to fit the camera) would project an image with a black circle around the edges. However, the elements of the subject that are inside both projected images will be of identical size on the film/sensor. I am referring to the physical image projected on the surface in the camera, not something produced from the film or file that can be recorded by the camera.


Skip Douglas
A few cameras and over 50 years behind them .....
..... but still learning all the time.

  
  LOG IN TO REPLY
lbennett
Senior Member
355 posts
Joined Dec 2006
     
Nov 12, 2008 12:50 |  #96

This might have already been mentioned, but a crop factor has the obvious benefit of increased focus point accuracy/visibility in the viewfinder.

For example (shooting wildlife)
case 1- crop I am actually point focusing on the elk's eyes or antlers
case 2- full frame I am only point focusing on the elk's body and hoping when I crop the sharp focus is there.

If you want to shoot detailed shots, you have to actually SEE the detail through your viewfinder. The argument that you can just crop down a full frame image, assuming you nailed focus, doesn't add up in real world use- at least for me.


Sale!  (external link)35L,  (external link)100L,  (external link)5DII (external link)

  
  LOG IN TO REPLY
pieq314
Goldmember
1,101 posts
Joined Apr 2006
     
Nov 12, 2008 12:55 |  #97

Willie wrote in post #6673322 (external link)
I know that crop has nothing to do with reach, if you are willing to crop a FF. My post said that if you don't want to crop, then the crop camera will have more reach. If I shoot with a 200mm on my crop camera and you also shoot with 200mm on FF, and if you don't have the time or want to crop all 300 hundred or whatever photos you took at the sporting event, then my images will have more "reach". That's all I said. It's a matter of convenience for me.

As far as convenience is convenience is concerned, yes, you may save the trouble of cropping if the bird happens to be at the right size for your longest lens (if the bird is too small, you will still need to crop). With a full frame, you will have to setup a photoshop action to automatically crop the whole folder by 1.6x (need about 30 sec to set up the action, and about another 30 sec to click buttons, and some minutes for the computer to process all the files in a folder).


Canon 1D Mk III/5D2, Sigma 50mm f/1.4, Sigma 24-70mm f/2.8 EX, Canon 24-105mm f/4L IS, Canon 70-200mm f/2.8L IS, Sigma 17-35mm f/2.8-4 EX, Canon 85/1.8, Canon 100/2.8 IS macro, Canon 135/2, Sigma 150-500 OS, Canon 500 f/4 IS

  
  LOG IN TO REPLY
Bodog
Goldmember
Avatar
1,306 posts
Joined Feb 2004
Location: Peculiar, MO
     
Nov 12, 2008 13:04 |  #98

tonylong wrote in post #6673314 (external link)
The image circle of the EF is larger, in other words projecting a wider field of view that covers a full frame sensor, the EF-S projects a smaller circle/field of view that covers a crop sensor. The field of view on the crop sensor is the same no matter which lens you use, though.

Forget the sensor. Just imagine the image is being projected on a blank wall. If the FOV is the same for both lenses, then the large circle and the small circle should have contain the same image, just larger and smaller versions. Since they don't, it appears (to me at least) that the EF-s has a narrower field of view and is in effect acting as a longer focal length.


JimE
Color? It's all relative...

  
  LOG IN TO REPLY
Willie
Senior Member
959 posts
Likes: 2
Joined Feb 2004
     
Nov 12, 2008 13:04 |  #99

pieq314 wrote in post #6673437 (external link)
As far as convenience is convenience is concerned, yes, you may save the trouble of cropping if the bird happens to be at the right size for your longest lens (if the bird is too small, you will still need to crop). With a full frame, you will have to setup a photoshop action to automatically crop the whole folder by 1.6x (need about 30 sec to set up the action, and about another 30 sec to click buttons, and some minutes for the computer to process all the files in a folder).

I'm no PS expert, so I wasn't sure if that was automatable. :)

I know that crop affects FOV only, I mentioned that in previous posts, but I also think the pixel density factor is getting to be more theoretical, given the high densities we have now, unless you are cropping a lot of information out.




  
  LOG IN TO REPLY
gjl711
According to the lazy TF, My flatulence rates
Avatar
55,381 posts
Likes: 2365
Joined Aug 2006
Location: Deep in the heart of Texas
     
Nov 12, 2008 13:09 |  #100

imageswest wrote in post #6673363 (external link)
My 5D gets crop on the sensor all the time... sometimes it gets so bad I have to send it in to Canon to have it cleaned. ;)

That is a real problem with 5D. ;):)


Not sure why, but call me JJ.
I used to hate math but then I realised decimals have a point.
.
::Flickr:: (external link)
::Gear::

  
  LOG IN TO REPLY
Willie
Senior Member
959 posts
Likes: 2
Joined Feb 2004
     
Nov 12, 2008 13:20 |  #101

Bodog wrote in post #6673495 (external link)
Forget the sensor. Just imagine the image is being projected on a blank wall. If the FOV is the same for both lenses, then the large circle and the small circle should have contain the same image, just larger and smaller versions. Since they don't, it appears (to me at least) that the EF-s has a narrower field of view and is in effect acting as a longer focal length.

Take a look at this link

http://en.wikipedia.or​g/wiki/Angle_of_view (external link)

The illustration below the title "Deriviation of the angle-of-view formula" shows how you get FOV. The dimension "d" is fixed, it is your sensor. The FL will not change as well. The only thing that will change is the physical size of the glass. Stretch out the element in the illustration (make it longer)and nothing changes. The lens will still focus the image on the sensor with the same FOV.

If you taped a medium format lens with the same FL it would also give you the same FOV. The only variable for FOV is the FL.




  
  LOG IN TO REPLY
tonylong
...winded
Avatar
54,657 posts
Gallery: 60 photos
Likes: 544
Joined Sep 2007
Location: Vancouver, WA USA
     
Nov 12, 2008 13:25 |  #102

Bodog wrote in post #6673495 (external link)
Forget the sensor. Just imagine the image is being projected on a blank wall. If the FOV is the same for both lenses, then the large circle and the small circle should have contain the same image, just larger and smaller versions. Since they don't, it appears (to me at least) that the EF-s has a narrower field of view and is in effect acting as a longer focal length.

You can't "forget the sensor" -- the EF-S lenses are designed for the crop sensor. As far as field of view goes, they project the same image/field of view on a sensor as an EF lens, but if you put a lens designed for a crop sensor on a full frame body, you will get the same image with the same field of view projected in the center with a dark circle around it. In other words, the lens projects an optical "crop" of what an equivalent EF lens would project.

So, the lens itself does not give any more "reach". If the crop sensor has more "pixels on target" than the full frame, well, that's one of the "advantages" of the crop cameras, as long as decent IQ is there, and that's the only "reach" involved -- nothing to do with EF-S lenses.


Tony
Two Canon cameras (5DC, 30D), three Canon lenses (24-105, 100-400, 100mm macro)
Tony Long Photos on PBase (external link)
Wildlife project pics here (external link), Biking Photog shoots here (external link), "Suburbia" project here (external link)! Mount St. Helens, Mount Hood pics here (external link)

  
  LOG IN TO REPLY
pieq314
Goldmember
1,101 posts
Joined Apr 2006
     
Nov 12, 2008 13:31 |  #103

Willie wrote in post #6673498 (external link)
I
I know that crop affects FOV only, I mentioned that in previous posts, but I also think the pixel density factor is getting to be more theoretical, given the high densities we have now, unless you are cropping a lot of information out.

50D's 15MP is probably at the limit. Additional pixels probably will not help much with providing additional resolution.

But 1Ds Mk III and 5D Mk II's 21MP does have room for more pixels. I have seen photos from 1Ds Mk III posted here that are extremely sharp at 100% crop --- meaning the lens is not yet the limiting factor (it was an expensive lens).


Canon 1D Mk III/5D2, Sigma 50mm f/1.4, Sigma 24-70mm f/2.8 EX, Canon 24-105mm f/4L IS, Canon 70-200mm f/2.8L IS, Sigma 17-35mm f/2.8-4 EX, Canon 85/1.8, Canon 100/2.8 IS macro, Canon 135/2, Sigma 150-500 OS, Canon 500 f/4 IS

  
  LOG IN TO REPLY
Bodog
Goldmember
Avatar
1,306 posts
Joined Feb 2004
Location: Peculiar, MO
     
Nov 12, 2008 13:37 |  #104

tonylong wrote in post #6673618 (external link)
You can't "forget the sensor" -- the EF-S lenses are designed for the crop sensor. As far as field of view goes, they project the same image/field of view on a sensor as an EF lens, but if you put a lens designed for a crop sensor on a full frame body, you will get the same image with the same field of view projected in the center with a dark circle around it. In other words, the lens projects an optical "crop" of what an equivalent EF lens would project.

But that is just the point I'm trying to make. The Ef-s is projecting a narrower field of view, so how can we say 200mm is 200mm. In this case it does not appear to be the same...


JimE
Color? It's all relative...

  
  LOG IN TO REPLY
gjl711
According to the lazy TF, My flatulence rates
Avatar
55,381 posts
Likes: 2365
Joined Aug 2006
Location: Deep in the heart of Texas
     
Nov 12, 2008 13:50 |  #105

Bodog wrote in post #6673679 (external link)
...The Ef-s is projecting a narrower field of view, so how can we say 200mm is 200mm. In this case it does not appear to be the same...

I think your falling off the rails because your assuming that FOV has something to do with focal length. The two are totally separate entities. 200mm = 200mm every time irrespective of FOV. The 200mm is referring to the focal length of the lens which is the distance from the nodal point to the sensor.In both examples the 200mm EF lens and a 55-250mm lens set to 200mm that distance is 200mm.


Not sure why, but call me JJ.
I used to hate math but then I realised decimals have a point.
.
::Flickr:: (external link)
::Gear::

  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)

15,521 views & 0 likes for this thread
Sensor Crop - A heated debate!
FORUMS Canon Cameras, Lenses & Accessories Canon EOS Digital Cameras 
AAA
x 1600
y 1600

Jump to forum...   •  Rules   •  Index   •  New posts   •  RTAT   •  'Best of'   •  Gallery   •  Gear   •  Reviews   •  Member list   •  Polls   •  Image rules   •  Search   •  Password reset

Not a member yet?
Register to forums
Registered members may log in to forums and access all the features: full search, image upload, follow forums, own gear list and ratings, likes, more forums, private messaging, thread follow, notifications, own gallery, all settings, view hosted photos, own reviews, see more and do more... and all is free. Don't be a stranger - register now and start posting!


COOKIES DISCLAIMER: This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and to our privacy policy.
Privacy policy and cookie usage info.


POWERED BY AMASS forum software 2.1forum software
version 2.1 /
code and design
by Pekka Saarinen ©
for photography-on-the.net

Latest registered member is fitactions
602 guests, 240 members online
Simultaneous users record so far is 15144, that happened on Nov 22, 2018

Photography-on-the.net Digital Photography Forums is the website for photographers and all who love great photos, camera and post processing techniques, gear talk, discussion and sharing. Professionals, hobbyists, newbies and those who don't even own a camera -- all are welcome regardless of skill, favourite brand, gear, gender or age. Registering and usage is free.