topic 70D Does Not Focus Properly in Single Point AF (Center Square) Viewfinder only in EOS DSLR & Mirrorless Cameras

70D Does Not Focus Properly in Single Point AF (Center Square) Viewfinder only

ddgtr — Tue, 06 May 2014 00:34:12 GMT

I suspected I had small focus problems with my 70D. So I thought I would thoroughly research it.

Last night I downloaded the test chart and procedure from Jeffrey Friedl's Blog (Thank you Jeffrey!) at http://regex.info/blog/photo-tech/focus-chart

I also downloaded another test chart from here:

http://photographylife.com/wp-content/uploads/2012/07/Focus-Test-Chart.pdf

And a third, from here http://cameralightlens.com/newsblog/?p=264 (thanks Scott!)

I followed his directions precisely, I also added another requirement of my own: in addition to being on a tripod and shooting in PLENTY of daylight at shutter speeds over 900, I also set the camera to fire in self timer mode, 2 seconds. This way I eliminated completely any possibility of me moving the camera while pressing the button.

I used two lenses:

EF 35mm f/2 IS USM

EF-S 18-135mm 1:3.5-5.6 IS STM

Two test charts, two techniques: Jeffrey's had to be shot at a 45 degree angle. The other one from photographylife had to be taped to a wall and shot at a 90 degree angle.

I must have shot at least 500 shots: from wide open f2 to f/5.6. One shot single focus point, to AI Servo multiple selections. Viewfinder shots and LiveView shots. 100% of the shots were in focus! The 35mm lens was a bit softer wide open at f2, but nothing blurry or anything drastic. Normal for this lens.

Now, this only covered focus at CLOSE distances. I then tried 20+ feet away and the results varied!! The LiveView was tack sharp even at f2! The viewfinder, however, was way blurry at f2. f2.8 was tons better, but NOT quite as sharp as LiveView at f2!! It was f4.5 that caught up with LiveView at f2! Same lighting, tripod, self timer mode, zero camera shake

Can any Canon technicians weigh in and let us know if this can be fixed with either a firmware update or a mechanical intervention?

Re: 70D Does Not Focus Properly in Single Point AF (Center Square) Viewfinder only

Mykolas — Wed, 07 May 2014 13:31:52 GMT

Hi ddgtr!

Thanks for posting.

Due to the wide variety of variables that can affect focus, it's going to be quite difficult to troubleshoot without getting our hands on your gear. I recommend that you give the technicians at our Factory Service Center the chance to perform detailed tests to determine if the camera and lenses are working properly or if re-calibration is necessary. To start your repair process, you'll need to complete a Repair Request on our website. You should include your camera, lenses, and sample images of the focus tests.

This didn't answer your question? Find more help at Contact Us.

Re: 70D Does Not Focus Properly in Single Point AF (Center Square) Viewfinder only

macdaddy — Sun, 25 Jan 2015 22:45:06 GMT

I recently sent my 70D in due to wildly horrific focus issues when using single shot manual point AF via the viewfinder. It is on it's way back to me with the notation that the engineers could find no issue and effected no repair. I get it back in two days and will try again but it simply blows me away that using the 70D the EXACT SAME WAY as you would any other camera is attributed to "user error" with regard to focus accuracy issues.

While the dual pixel AF feature is all great and perfect when using the LCD, it is simply inexcusable that the standard contrast detection (with enhanced cross-point, no less) sucks so horribly. And it boggles my mind that certain people blame the user on this but absolutely NONE of those same people can define the exact settings you need to use to get the single point AF to work as precisely as all the other cameras I've used in the past have been able to do.

Sadly, I'm about to run out of my return timeframe for the camera and need to make a quick decision to keep it or return it and switch to Nikon (I just switched to Canon from Pentax in order to enjoy the better AF and image output). To say I am worried is one thing. To say I am setting up to be sorely disappointed would be accurate.

I'm crossing my fingers that I find the magic bullet in two days. Otherwise, I will be a very unhappy Canon customer.