The Canon EOS and Photography Forums

Photography Forums => The Canon EOS Forum => Topic started by: mike_tee_vee on March 01, 2009, 08:44:11 AM



Title: Viewfinder magnification
Post by: mike_tee_vee on March 01, 2009, 08:44:11 AM
Is there anything that prevents autofocus SLRs from having larger magnifications?  When picking up old Contax RTS and Nikon FE bodies, the first thing I notice is that the viewfinders size dwarfs any modern day full frame SLR viewfinder. 

Is there any technical limitation to having a 0.88x viewfinder in a modern DSLR?


Title: Re: Viewfinder magnification
Post by: Bob Atkins on March 01, 2009, 11:34:14 AM
The higher the magnification, the dimmer the viewfinder image will be, so while there is no technical reason why you couldn't have a higher magnification, there are some practical reasons. This especially applies to crop sensor cameras, where to get a viewfinder image as large as that from a full frame camera, you need higher magnification. With low end cameras (Digital Rebels) there's an additional factor becaus they use a "pentamirror" system (to save weight and cost) and that in itself makes the viewfinder image dimmer.

There's also another factor, eye relief. This is the distance from the viewfinder at which you can still see all the image. Most cameras have an eye relief of around 20mm or more, so that you can still see the viewfinder image if you are wearing glasses. One easy way to get good eye relief is to make the magnification smaller.


Title: Re: Viewfinder magnification
Post by: klindup on March 01, 2009, 04:38:20 PM
Could not the eye relief be deallt with by the design of the lens in the eyepiece.  I assume that there is some relationship between magnification, the focal length of the eyepiece and the focal length of the camera lens.  I realise that the eyepiece lens in a camera is orders of magnitude lower than say a radian eyepiece from Al Naglar.

Ken Lindup


Title: Re: Viewfinder magnification
Post by: Bob Atkins on March 01, 2009, 05:52:15 PM
I'm sure it could be done, but since there is no critical demand by consumers for a larger viewfinder, it's not high priority. Basically, it wouldn't sell more cameras.

Most photographers are now used to smaller viewfinders. You do hear compaints from old dinosaurs (like me) who can remember a few cameras with 1x viewfinders - in fact I think I still have an old Yashica body with a 1x viewfinder - but most current photographers have no experience of large, high magnification viewfinders. Even I'm OK with current DSLR viewfinders. I'm used to the 40D and 5D now.

So I think 1x viewfinders are a thing of the past. If Canon (and Nikon etc.) are going to put money into R&D it will probably go to adding video to DSLRs, lowering noise, increasing ISO, increasing pixel count etc., not making the viewfinder bigger or brighter.


Title: Re: Viewfinder magnification
Post by: KeithB on March 02, 2009, 10:40:55 AM
Good Reliable Autofocus killed the big finder.  You don't need a big finder if it is strictly a composing tool.  If focusing is critical (like for macro), you can get a magnifiying eyepiece that will let you see a magnified chunk of the middle of the frame...


Title: Re: Viewfinder magnification
Post by: mike_tee_vee on March 05, 2009, 08:19:45 AM
I do realize that smaller viewfinders have become the norm, but it does seem strange how there hasn't been much demand to increase magnification.

No new cameras ship with a 1.8" LCD any more, and 15" computer monitors are virtually extinct.  With an aging population, bigger visuals appear to be in higher demand.

LCDs on cameras have progressed to 3.0" VGA resolutions, and I just wonder why viewfinder technology hasn't shown the same progress.  We typically spend at least as much time peering through a viewfinder as we do a rear screen.

End of rant ;)


Title: Re: Viewfinder magnification
Post by: Bob Atkins on March 05, 2009, 12:08:14 PM
Perphaps people just don't know any better! Yesterday I was shooting in a studio and switching rapidly between a 5D and a 40D (with different lenses). While I don't normally notice the smaller viewfinder of the 40D, when rapisly switching between the two cameras it was quite evident that the 5D had the larger, clearer viewfinder.

As for LCD screen, 1.5" was to small and an obvious problem at the outset. I simply couldn't read text on a 1.5" screen without reading glasses. With a 3" screen I can read the text, so it's a 1000% improvement for me. Sinc ethe viewfinders have a diopter correction built in, I can see both a small and large screen equally clearly. It's mainly just an aiming device for AF cameras, so you really don't need it to be big.