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Bruce's Photo Blog
Bruce Foreman | November 2013

Optical Viewfinder...Or Electronic Viewfinder?

For decades all we had were optical viewfinders whether they were direct view or reflex type (mirror between the lens and focusing screen).  Rangefinder type cameras like the Leica M series, the Nikon and Canon copies, and others like a Yashica I had were all the direct view kind.  Used primarily for framing and composition and sometimes there was a co-incident rangefinder image coupled for focusing.

Then with the advent of reflex cameras that incorporated a mirror and focusing screen we had a good way to begin to pre-visualize in the camera itself.  Early film SLRs (Single Lens Reflex) had a focusing screen on top of the camera with a folding hood to block out daylight to some extent.  Then along came the eye level prism finder, built in on some cameras, sliding into place on others.  TLRs (Twin Lens Reflex) had a lens above the actual taking lens that focused an image on a ground glass screen on the top of the camera and there was a folding hood with a flip up magnifier.  I had several by Yashica, Rollei, and Mamiya.

When digital technology came on the scene the major SLR manufacturers started out by simply replacing the film plane with the sensor (and necessary electronics) and everything else functioned the same.  The photographer looked through the eye level prism finder (or pentamirror setup) to view and focus, when the shutter release was pressed the mirror flipped up and cleared the light path to the sensor, the shutter opened and closed, and the mirror came back down. 

A few compact zoom cameras had an electronic viewfinder (EVF) but early models had a few minor problems.  Image lag, and image smearing were two.  My first serious digital camera was an HP 5MP model and the image lag problem caused me to spring the $999 the original Canon Digital Rebel cost at the time.

But the advent of the mirrorless interchangeble lens camera changed that.   Olympus brought the Pen series to market by going back to their half frame film camera design and bringing that basic concept into the digital age in Micro Four Thirds (MFT) form.  These had an LCD on the back as the main viewfinder and after the first model they incorporated a port that allowed use of an external EVF.  At about the same time frame Panasonic introduced their Lumix G series in MFT with a built in EVF, both systems enjoyed success.

My first experience with built in EVF was with the Panasonic lumix GH2 and I adapted to that easily (I'd already started using an Olympus Pen with an external EVF and that helped).  So which is better, the optical finder or the EVF?

Depends on the individual.  Some who've come up through the decades using traditional SLRs have become very used to dealing with a bright easy to see and focus image.  It's addictive.  But for me when the Rebels hit the market in digital form they switched from the bright prism finder to the pentamirror setup and suddenly the image I was used to in Nikon F series was not nearly as large and not as bright.  When I got into the MFT system with EVF I began to see a viewfinder image that gave me instant feedback on photo results without taking the camera down.  The image in the finder “froze” for 2 seconds (touching the release again cleared it before then if necessary) after taking the shot.  If  in Manual mode with the Lumix GH2 or GH3 I could generally see exposure effect before pushing the shutter release making previsualization much more effective.

People really used to the bright prism finder image may have a bit of trouble trying to adjust to an EVF image.  It has been no problem for me but then I've become more used to a leisurely approach to my photography and I enjoy the benefits of an EVF which gives me a better idea what my photo is going to look like.  Plus there is an added benefit of being able to see the image without having to fight what bright daylight and sunlight do to viewing on an LCD.

Where is this all going in the future?  Well, I think the future is mirrorless and when the mirror goes, there goes the optical finder.  Taking the mirror and mirror box out of the body design simplifies mechanisms, makes the whole camera somewhat less prone to mechanical malfunction.  Next thing to go will likely be the shutter, my current model (Lumix GH3) has a menu choice for quiet operation where the mechanical shutter is left open and and electronic shutter (sensor scan) is used instead.

Progress gets interesting...

— Bruce Foreman