Sony SEL 50F18 on APS-C vs. FF camera
Old 09-23-2016   #1
MIkhail
Registered User
 
MIkhail's Avatar
 
MIkhail is offline
Join Date: Nov 2005
Location: Detroit, Michigan
Posts: 844
Sony SEL 50F18 on APS-C vs. FF camera

I have a quick question.

The Sony SEL 50F18 lens (which is 50mm) gives an equivalent of 75mm on APS-C sensor camera, like NEX6, for example. Well, not really a 75mm but a crop equal a picture from 75mm lens. I know that.
Question is- on FF camera like for example Sony a7, will the picture still be equivalent of 75mm as far as width, or is it becomes true 50mm width picture?

Thank you.
  Reply With Quote

Old 09-23-2016   #2
jarski
Registered User
 
jarski is offline
Join Date: Jan 2007
Posts: 2,300
Quote:
Originally Posted by MIkhail View Post
Question is- on FF camera like for example Sony a7, will the picture still be equivalent of 75mm as far as width, or is it becomes true 50mm width picture?
Image circle of that lens does not cover full frame sensor. Either A7 recognize this and turns to crop mode (75mm), or you will get 50mm image with dark corners.
  Reply With Quote

Old 09-23-2016   #3
MIkhail
Registered User
 
MIkhail's Avatar
 
MIkhail is offline
Join Date: Nov 2005
Location: Detroit, Michigan
Posts: 844
Quote:
Originally Posted by jarski View Post
Image circle of that lens does not cover full frame sensor. Either A7 recognize this and turns to crop mode (75mm), or you will get 50mm image with dark corners.

Thanks for answering.
So do I get it right that if the a7 does not do automatic cropping you would get true 50mm except with dark corners?
  Reply With Quote

Old 09-23-2016   #4
peterm1
Registered User
 
peterm1's Avatar
 
peterm1 is offline
Join Date: May 2006
Posts: 3,971
Quote:
Originally Posted by MIkhail View Post
Thanks for answering.
So do I get it right that if the a7 does not do automatic cropping you would get true 50mm except with dark corners?
As I understand it the Sony full frame camera software automatically recognizes that a crop sensor Sony lens has been mounted and automatically switches to crop sensor mode. But this can also be turned off in the camera's settings if you want to. This is how Nikon full frame cameras work.

You may be confused about what people mean when they talk about a 50mm crop sensor lens being like a 75mm lens. This lens is always 50mm lens no matter what camera it is mounted on. This never changes. But if mounted on a camera with a smaller sensor (one with a crop sensor - which it was designed for) only the middle of its image gets recorded because that sensor is smaller. This makes the final image look like it was taken by a 75mm lens (in this case) as it seems to give a closer view just like a "true" 75mm lens would on a full frame camera.

But lenses designed for crop sensor cameras are not designed to "throw" an image circle big enough to cover a full frame sized sensor (which is why they tend to be smaller than full frame lenses which usually have bigger optics inside them). So if you mount it on a Sony full frame camera you will get a black area around the image recorded on the full frame sensor (called vignetting) or the image has to be cropped to get rid of this. Usually this can be done automatically inside the camera by its firmware which discards the black part of the image which did not receive any light from the lens. Or you can turn this feature off in firmware and do it manually afterwards using photo shop etc.
  Reply With Quote

Old 09-23-2016   #5
MIkhail
Registered User
 
MIkhail's Avatar
 
MIkhail is offline
Join Date: Nov 2005
Location: Detroit, Michigan
Posts: 844
Quote:
Originally Posted by peterm1 View Post
As I understand it the Sony full frame camera software automatically recognizes that a crop sensor Sony lens has been mounted and automatically switches to crop sensor mode. But this can also be turned off in the camera's settings if you want to. This is how Nikon full frame cameras work.

You may be confused about what people mean when they talk about a 50mm crop sensor lens being like a 75mm lens. This lens is always 50mm lens no matter what camera it is mounted on. This never changes. But if mounted on a camera with a smaller sensor (one with a crop sensor - which it was designed for) only the middle of its image gets recorded because that sensor is smaller. This makes the final image look like it was taken by a 75mm lens (in this case) as it seems to give a closer view just like a "true" 75mm lens would on a full frame camera.

But lenses designed for crop sensor cameras are not designed to "throw" an image circle big enough to cover a full frame sized sensor (which is why they tend to be smaller than full frame lenses which usually have bigger optics inside them). So if you mount it on a Sony full frame camera you will get a black area around the image recorded on the full frame sensor (called vignetting) or the image has to be cropped to get rid of this. Usually this can be done automatically inside the camera by its firmware which discards the black part of the image which did not receive any light from the lens. Or you can turn this feature off in firmware and do it manually afterwards using photo shop etc.

Thank you.
That's what I figured.
Makes sense.
  Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -8. The time now is 14:47.


vBulletin skin developed by: eXtremepixels
Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

All content on this site is Copyright Protected and owned by its respective owner. You may link to content on this site but you may not reproduce any of it in whole or part without written consent from its owner.