Go Back   Rangefinderforum.com > Non Rangefinder Cameras > CSC : Digital Compact System Cameras - > Micro 4/3 Cameras

Micro 4/3 Cameras This forum is for all Micro 4/3 cameras of any camera make.

Closed Thread
 
Thread Tools Display Modes

crop factor
Old 07-08-2010   #1
hitmanh
dum de dum de doo
 
hitmanh's Avatar
 
hitmanh is offline
Join Date: Nov 2006
Location: Cambridge, UK
Posts: 195
crop factor

Can anyone tell what crop factors C mount and Oly Pen F lenses would have on a 4/3 camera?

Cheers

Matt
__________________
http://www.hitmanh.com

I don't care if you are afraid of shadows, diminishing MY rights because of your irrational fears is still wrong, will always be wrong, and always has been WRONG
 

Old 07-08-2010   #2
back alley
ɹoʇɐɹǝpoɯ moderator
 
back alley's Avatar
 
back alley is offline
Join Date: Jul 2003
Location: searching for the perfect bag!
Posts: 37,567
2x



.
__________________
heart soul & a camera

x-e1/23/56/16-50


http://crated.com/backalleyimages
 

Old 07-08-2010   #3
ferider
Registered User
 
ferider's Avatar
 
ferider is offline
Join Date: May 2005
Posts: 10,141
Should be sqrt(2) = 1.4...
__________________
50mm Project, => Vote Now
Smugmug
 

Old 07-08-2010   #4
back alley
ɹoʇɐɹǝpoɯ moderator
 
back alley's Avatar
 
back alley is offline
Join Date: Jul 2003
Location: searching for the perfect bag!
Posts: 37,567
isn't the crop factor dependent on the cmaera and not the lens used?

the m4/3 have a crop factor of 2. a 20 mm lens is a 40 on the m/43, no?
__________________
heart soul & a camera

x-e1/23/56/16-50


http://crated.com/backalleyimages
 

Old 07-08-2010   #5
rover
Moderator
 
rover's Avatar
 
rover is offline
Join Date: Jul 2003
Location: Connecticut
Age: 48
Posts: 13,941
I would have voted for 2x too, but I have a feeling Roland is going to lay down some serious education on us.

In the end a 20 does have a 40 fov, so I am just laying back on this one to see how folks get to that answer.
__________________
Dad with a Camera

Millennium M6TTL with Voigtlander 35/1.2 Nokton

rover's world at flickr
 

Old 07-08-2010   #6
hitmanh
dum de dum de doo
 
hitmanh's Avatar
 
hitmanh is offline
Join Date: Nov 2006
Location: Cambridge, UK
Posts: 195
Quote:
Originally Posted by back alley View Post
isn't the crop factor dependent on the cmaera and not the lens used?

the m4/3 have a crop factor of 2. a 20 mm lens is a 40 on the m/43, no?
True for a lens designed to cover a 35mm film plane, which the C mount and Pen F lenses are not as far as I know. I'm wondering if they will have less of a crop factor as they're design to cover a smaller film plane.

Cheers

Matt
__________________
http://www.hitmanh.com

I don't care if you are afraid of shadows, diminishing MY rights because of your irrational fears is still wrong, will always be wrong, and always has been WRONG
 

Old 07-08-2010   #7
back alley
ɹoʇɐɹǝpoɯ moderator
 
back alley's Avatar
 
back alley is offline
Join Date: Jul 2003
Location: searching for the perfect bag!
Posts: 37,567
so, it was a trick question...
__________________
heart soul & a camera

x-e1/23/56/16-50


http://crated.com/backalleyimages
 

Old 07-08-2010   #8
hitmanh
dum de dum de doo
 
hitmanh's Avatar
 
hitmanh is offline
Join Date: Nov 2006
Location: Cambridge, UK
Posts: 195
Quote:
Originally Posted by back alley View Post
so, it was a trick question...
hehe, not really, I was just wondering if anyone had worked it out. I'm considering a 4/3 camera but the 2x crop put me off a little. If using Pen F or C mount can reduce that somewhat, I'd be happier.
__________________
http://www.hitmanh.com

I don't care if you are afraid of shadows, diminishing MY rights because of your irrational fears is still wrong, will always be wrong, and always has been WRONG
 

Old 07-08-2010   #9
ferider
Registered User
 
ferider's Avatar
 
ferider is offline
Join Date: May 2005
Posts: 10,141
Compared to full format, C mount and Oly Pen F are designed for a crop factor of 1.4. At least that's the image circle that they cover. For example, my 38mm Pen FT lens has roughly the FOV of a 50mm on full format (53 actually).

When using on u4/3 you reduce the image and decrease the FOV by another factor 1.4. So, in total, when compared to full frame, you have a factor 1.4 * 1.4 = 2.

So a Pen F 38mm lens on u4/3 will have the same FOV as a 76mm lens on full frame.

The advantage of C-mount lenses on u4/3 is that you can get very fast, relatively wide lenses.

Hope that makes sense,

Roland.
__________________
50mm Project, => Vote Now
Smugmug
 

Old 07-08-2010   #10
rover
Moderator
 
rover's Avatar
 
rover is offline
Join Date: Jul 2003
Location: Connecticut
Age: 48
Posts: 13,941
38x2=76

Yup, same answer, different algebra
__________________
Dad with a Camera

Millennium M6TTL with Voigtlander 35/1.2 Nokton

rover's world at flickr
 

Old 07-08-2010   #11
hitmanh
dum de dum de doo
 
hitmanh's Avatar
 
hitmanh is offline
Join Date: Nov 2006
Location: Cambridge, UK
Posts: 195
Quote:
Originally Posted by ferider View Post
Compared to full format, C mount and Oly Pen F are designed for a crop factor of 1.4. At least that's the image circle that they cover. For example, my 38mm Pen FT lens has roughly the FOV of a 50mm on full format (53 actually).

When using on u4/3 you reduce the image and decrease the FOV by another factor 1.4. So, in total, when compared to full frame, you have a factor 1.4 * 1.4 = 2.

So a Pen F 38mm lens on u4/3 will have the same FOV as a 76mm lens on full frame.

The advantage of C-mount lenses on u4/3 is that you can get very fast, relatively wide lenses.

Hope that makes sense,

Roland.
Lovely, just what I wanted to know!

Thanks

Matt
__________________
http://www.hitmanh.com

I don't care if you are afraid of shadows, diminishing MY rights because of your irrational fears is still wrong, will always be wrong, and always has been WRONG
 

Old 07-08-2010   #12
back alley
ɹoʇɐɹǝpoɯ moderator
 
back alley's Avatar
 
back alley is offline
Join Date: Jul 2003
Location: searching for the perfect bag!
Posts: 37,567
headache....alert...
__________________
heart soul & a camera

x-e1/23/56/16-50


http://crated.com/backalleyimages
 

Old 07-08-2010   #13
back alley
ɹoʇɐɹǝpoɯ moderator
 
back alley's Avatar
 
back alley is offline
Join Date: Jul 2003
Location: searching for the perfect bag!
Posts: 37,567
Quote:
Originally Posted by FrankS View Post
Oh, measured with tactical lasers.
i have a piece of string...
__________________
heart soul & a camera

x-e1/23/56/16-50


http://crated.com/backalleyimages
 

Old 07-08-2010   #14
ferider
Registered User
 
ferider's Avatar
 
ferider is offline
Join Date: May 2005
Posts: 10,141
Quote:
Originally Posted by back alley View Post
i have a piece of string...
Can I use it as a garrote ?
__________________
50mm Project, => Vote Now
Smugmug
 

Old 07-08-2010   #15
hitmanh
dum de dum de doo
 
hitmanh's Avatar
 
hitmanh is offline
Join Date: Nov 2006
Location: Cambridge, UK
Posts: 195
Lol, sometimes I wish I kept my mouth shut ^^
__________________
http://www.hitmanh.com

I don't care if you are afraid of shadows, diminishing MY rights because of your irrational fears is still wrong, will always be wrong, and always has been WRONG
 

Old 07-08-2010   #16
Brian Sweeney
Registered User
 
Brian Sweeney's Avatar
 
Brian Sweeney is offline
Join Date: Jan 2004
Posts: 14,897
C-Mount lenses are made for different size sensors. The "closest" that you will find for u4/3rds camera are the lenses made for a 1" sensor. For that format, a 25mm lens is the normal for the C-Mount and is normal for the u4/3rds. I am waiting for a C-Mount adapter to try my Kowa 12.5mm F1.4 lens made for a 1" Vidicon.

As far as a lot of algebra and opinions, the term "close-enough" applies here.

You guys don't pronounce "LASERS" correctly, and do not have one that would have just melted the lens.

Last edited by Brian Sweeney : 07-08-2010 at 15:54.
 

Old 07-08-2010   #17
Brian Sweeney
Registered User
 
Brian Sweeney's Avatar
 
Brian Sweeney is offline
Join Date: Jan 2004
Posts: 14,897
This thread has gone off on a tangent that is far from the simple question asked by the OP.

A simple question was asked, and some simple answers were given.

If you want to get off on this overly-technical debate, take it to another thread.

This one is going to get turned into a simple answer to a simple question very soon.

Last edited by Brian Sweeney : 07-08-2010 at 17:15.
 

Old 07-08-2010   #18
gdi
Registered User
 
gdi is offline
Join Date: Nov 2006
Location: West-Central Connecticut
Posts: 2,370
Quote:
Originally Posted by Brian Sweeney View Post
This thread has gone off on a tangent that is far from the simple question asked by the OP.

A simple question was asked, and some simple answers were given.

If you want to get off on this overly-technical debate, take it to another thread.

This one is going to get turned into a simple answer to a simple question very soon.
"the gad-fly cometh, it cometh from the"... Left Coast
 

Old 07-08-2010   #19
Brian Sweeney
Registered User
 
Brian Sweeney's Avatar
 
Brian Sweeney is offline
Join Date: Jan 2004
Posts: 14,897
Okay. The OP asked a simple question, and had his thread Trolled.

Start this Tangential discussion elsewhere.

You made the OP wish he had not asked the question.

That is NOT what RFF is about.

This thread has been edited to filter out the tangential discussion, hopefully allow the answers to the question to come through, and not make anyone want to choke another RFF member with a garrote.

Last edited by Brian Sweeney : 07-08-2010 at 17:46.
 
Closed Thread


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

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



All times are GMT -8. The time now is 05:31.


vBulletin skin developed by: eXtremepixels
Powered by vBulletin® Version 3.6.8
Copyright ©2000 - 2014, 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.