Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Canon EOS dSLR

Reply
 
Thread Tools Search this Thread
Old Apr 2, 2010, 10:59 AM   #11
Super Moderator
 
Mark1616's Avatar
 
Join Date: Oct 2005
Posts: 7,397
Default

Quote:
Originally Posted by Widowmaker View Post
Without getting technical.... on that body, using that lens, you basically have a 27-88 mm lens. The fact that its an EF-S does not change that.
Nope, using that lens you have a 17-55, nothing changes that.

What is changed is the field of view. As an example my little SX1 has a 5 - 100mm lens, that is the focal length of the lens, but the small sensor makes it have a similar field of view compared for 35mm film as 28-560mm.

This thread should help.

http://forums.steves-digicams.com/ge...op-factor.html
Mark1616 is offline   Reply With Quote
Old Apr 2, 2010, 11:21 AM   #12
Senior Member
 
Widowmaker's Avatar
 
Join Date: Jul 2003
Location: Bakersfield, CA
Posts: 851
Default

Quote:
Originally Posted by Mark1616 View Post
Nope, using that lens you have a 17-55, nothing changes that.

What is changed is the field of view. As an example my little SX1 has a 5 - 100mm lens, that is the focal length of the lens, but the small sensor makes it have a similar field of view compared for 35mm film as 28-560mm.

This thread should help.

http://forums.steves-digicams.com/ge...op-factor.html
Why does everyone here have to try to get so technical? Notice the word BASICALLY. I don't think anyone here actually thinks the lens magically changed physically.

At the end of the day using that lens on that body, the end result will be the same as using a 27-88mm on a full frame. So in all respects that MATTER in the situation, the lens is basically 27-88mm... Arguing otherwise is simply for the sake of arguing. In that case let me see you get a 18mm field of view with that lens on that body without changing the subject distance. So its very logical to view it as a 27-88 than not.

Last edited by Widowmaker; Apr 2, 2010 at 11:28 AM.
Widowmaker is offline   Reply With Quote
Old Apr 2, 2010, 11:44 AM   #13
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,544
Default

The problem is that, if you talk about the 18-55mm focal length becoming a 27-88mm focal length, and later, someone comes upon this thread and sees that the focal length changed, they aren't going to know that you didn't really mean it.

Case in point:
Quote:
Originally Posted by FaithfulPastor View Post
The 18mm setting x 1.6 means I actually shooting at a 29 focal length.
It may be a crutch to help you understand what's going on, but if someone else doesn't need the crutch, don't saddle them with it.
__________________
  • The lens is the thing.
  • 'Full Frame' is the new 'Medium Format'.
  • "One good test is worth a thousand expert opinions." - Tex Johnston, Boeing 707 test pilot.
TCav is offline   Reply With Quote
Old Apr 2, 2010, 12:31 PM   #14
Senior Member
 
Widowmaker's Avatar
 
Join Date: Jul 2003
Location: Bakersfield, CA
Posts: 851
Default

Crutch? So if something is explained or viewed in a way other than you or others would explain it, its a crutch? That is somewhat of a narrow field of view isn't it? pun intended

The cameras sensor will record a 27-88 mm FOV, so in that respect, since you will not be able to produce a 17mm FOV on the sensor at 17mm physically on the lens nor a 55mm FOV on the sensor at 55mm physically on the lens... it can be viewed as a 27-88 whether that sits well with others explanations or not.
Widowmaker is offline   Reply With Quote
Old Apr 2, 2010, 12:33 PM   #15
Super Moderator
 
Mark1616's Avatar
 
Join Date: Oct 2005
Posts: 7,397
Default

Quote:
Originally Posted by Widowmaker View Post
Why does everyone here have to try to get so technical? Notice the word BASICALLY. I don't think anyone here actually thinks the lens magically changed physically.

At the end of the day using that lens on that body, the end result will be the same as using a 27-88mm on a full frame. So in all respects that MATTER in the situation, the lens is basically 27-88mm... Arguing otherwise is simply for the sake of arguing. In that case let me see you get a 18mm field of view with that lens on that body without changing the subject distance. So its very logical to view it as a 27-88 than not.
Why should we assume that everyone is incapable of understanding what is happening? I don't think people using APS cameras back in the day were bothered about the crop factor etc, so why is it such a difficult thing now.

I use cameras that are FF, 1.3x and 1.6x crops, I don't spend a lot of time thinking I need to use this lens as it is going to be (n) focal length, I just use the right tool for the job.

If someone is trying to compare then it is helpful, outside of that is not helpful to think of anything apart from the real focal length rather than the crop.
Mark1616 is offline   Reply With Quote
Old Apr 2, 2010, 1:00 PM   #16
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,544
Default

It's a crutch because it lets you understand how the angle of view changes with the size of the image sensor. The focal length doesn't change. The "35mm equivalent focal length" changes. But the "35mm equivalent focal length" is a crutch for people that use different size image sensors. If someone only uses an APS-C image sensor, they don't need the crutch. When you explain something to them by invoking that "35mm equivalent focal length" by referring to it as the "focal length", it only serves to throw a monkey wrench into their understanding of it.

You use the crutch, and that's ok. That's how you understand it. But they don't need the crutch. This topic was started because FaithfulPastor thought he needed the crutch, because someone else explained something to him using the crutch, and he's been carrying that crutch around with him ever since.
__________________
  • The lens is the thing.
  • 'Full Frame' is the new 'Medium Format'.
  • "One good test is worth a thousand expert opinions." - Tex Johnston, Boeing 707 test pilot.
TCav is offline   Reply With Quote
Old Apr 2, 2010, 1:17 PM   #17
Senior Member
 
Widowmaker's Avatar
 
Join Date: Jul 2003
Location: Bakersfield, CA
Posts: 851
Default

Why must we assume that everyone wants to know exactly what is happening? Maybe someone just wants to know that if they stick this lens on this camera will they get the same view as if they used the same lens on a another camera.

This is why I said.. "Without getting technical" and "Basically" . You seemed to quote and respond to me direclty with..."Nope, using that lens you have a 17-55, nothing changes that." must have been for the sake of argument or to open the opportunity to get technical because my statement never suggested the lens magically transforms into a 27-88mm.
Widowmaker is offline   Reply With Quote
Old Apr 2, 2010, 1:27 PM   #18
Senior Member
 
Widowmaker's Avatar
 
Join Date: Jul 2003
Location: Bakersfield, CA
Posts: 851
Default

Quote:
Originally Posted by TCav View Post
It's a crutch because it lets you understand how the angle of view changes with the size of the image sensor. The focal length doesn't change. The "35mm equivalent focal length" changes. But the "35mm equivalent focal length" is a crutch for people that use different size image sensors. If someone only uses an APS-C image sensor, they don't need the crutch. When you explain something to them by invoking that "35mm equivalent focal length" by referring to it as the "focal length", it only serves to throw a monkey wrench into their understanding of it.

You use the crutch, and that's ok. That's how you understand it. But they don't need the crutch. This topic was started because FaithfulPastor thought he needed the crutch, because someone else explained something to him using the crutch, and he's been carrying that crutch around with him ever since.
You consider it a crutch because its not the way you choose to explain it. I understand completely what is happening with crop factor bodies, because I choose to explain or give examples that are not technical does not make them a crutch. A technical response is not always necessary.. maybe not seeing that is your crutch.
Widowmaker is offline   Reply With Quote
Old Apr 2, 2010, 1:35 PM   #19
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,544
Default

Without getting technical, the angle of view changes from 74 to 47.

What's wrong with saying it like that instead? It's correct, and it doesn't invoke anything that might be misinterpreted.
__________________
  • The lens is the thing.
  • 'Full Frame' is the new 'Medium Format'.
  • "One good test is worth a thousand expert opinions." - Tex Johnston, Boeing 707 test pilot.
TCav is offline   Reply With Quote
Old Apr 2, 2010, 1:48 PM   #20
Senior Member
 
Widowmaker's Avatar
 
Join Date: Jul 2003
Location: Bakersfield, CA
Posts: 851
Default

Quote:
Originally Posted by TCav View Post
Without getting technical, the angle of view changes from 74 to 47.

What's wrong with saying it like that instead? It's correct, and it doesn't invoke anything that might be misinterpreted.
Whats ? just kidding.
Widowmaker is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 11:34 PM.