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

Thread Tools Search this Thread
Old May 15, 2005, 10:38 PM   #1
Join Date: May 2005
Posts: 84

Like will objects be twice as large as normal in a 200mm lens? Three times? And what about other lenths? 400mm? 600mm?

Is there an easy equation to figure this out?
crash331 is offline   Reply With Quote
Sponsored Links
Old May 23, 2005, 10:59 PM   #2
Join Date: Apr 2005
Posts: 52

What ever the factor is, it will stay the same no matter what focal lenght you use. For a Dig rebel, 20D it is 1.6 so a 100 mm will become an effective 1.6*100 or 160mm. Same for a 200mm lens 200*1.6=320mm
miatapaul is offline   Reply With Quote
Old May 23, 2005, 11:50 PM   #3
Senior Member
rob_strain's Avatar
Join Date: Jul 2004
Location: Fort Knox, Ky.
Posts: 282

You cant think in terms of magnification. Think in terms of field of view. I can't find the equivalent field of view for each length of lens, but I'm sure someone else here can point you in the right direction.
rob_strain is offline   Reply With Quote
Old May 24, 2005, 6:37 AM   #4
Senior Member
mactek's Avatar
Join Date: Jun 2004
Posts: 347

I could be wrong, but I think the question being asked has to do with consumer cameras having, say, 3x optical zoom, as an example. As far as I can tell, all of the consumer cameras take their longest focal length equivalent and divide by 35mm, so a camera with an equivalent of at least a 105mm lens is a 3x optical zoom camera.

For instance, my old Nikon CP5700 had a 9-72mm Zoom-Nikkor (equivalent to 35-280mm in 35mm photography). They divided 280mm by 35mm to get 8x optical zoom.

mactek is offline   Reply With Quote
Old May 24, 2005, 3:10 PM   #5
Senior Member
NHL's Avatar
Join Date: Jun 2002
Location: 39.18776, -77.311353333333
Posts: 11,567

In 35mm parlance a standard lens is around ~50mm, a normal person Field Of View (FOV). A 200mm is then 200/50 = 4x time the normal FOV while a 400mm is 400/50 = 8x the regular FOV.

If you get a 50-500mm zoom then the zoom ratio is 10x, and the FOV is 1x to 10x...

However if you get a 35-350mm zoom instead, the zoom ratio is still 10x, but the FOV is now 0.7x to 7x, i.e. it goes a little wider, but has less magnification at the long
NHL is offline   Reply With Quote

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 6:24 AM.