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DPChallenge Forums >> Hardware and Software >> Testing camera for focus issue
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08/22/2016 11:49:14 AM · #1
I have noticed recently a lot of my photos taken with my Canon 70D seem to completely missing focus. My first thought was it is just my own technical errors but I am now wondering if there is a possibility that my camera is misbehaving.

For example this image completely missed focusing on the pony and I am sure I used a single focus point.



I really am getting a lot of photos with the subject not in focus and hope it is not just human error.

Any suggestions on how to narrow down the issue much appreciated.

I am thinking of upgrading to either a 5D Mark ii or 6D but if it is human error I think I need to perfect my skills first.

Edited to add another example:



Message edited by author 2016-08-22 11:52:23.
08/22/2016 11:59:19 AM · #2
Your 7D has "Microfocus adjustment" that allows you to adjust front- or back-focus issues for each lens paired with the camera. It looks as if you DO have a front-focus issue based on what you've said and what you have shown us, but you can adjust for that yourself. Check your manual or google for help. It would be worth checking if the issue is present with other lenses as well, since both images you showed us are with the 17-55mm f/2.8 lens...
08/22/2016 12:19:58 PM · #3
Thanks Robert - I will look into that.

Here is one with a similar issue taken with the 85mm



I am not discounting the issue may be just me but just seems to be happening a lot recently and it is disheartening thinking I have a great subject and getting lousy results

I was thinking there may be some tests I could do with the camera on a tripod to try and confirm if there is an issue with the camera or not. I did read of issues with AF on the 70D but this problem only seems to have raised its ugly head relatively recently

08/22/2016 12:38:24 PM · #4
Because of the way PDAF focusing works there can be error in the focusing, that's why the manufactures have included a way to make small adjustment to the focusing. These adjustments are lens specific and the camera should allow for adjustment for each lens you attach and store those results (as well as based on a TC attached). I use The Focus Tune System for my adjustments and have found it very easy to use, I purchased both the software and target and I am glad that I did. You can do it without this system but it really is hit or miss. You can focus on the same thing over and over and the camera will focus a little different each time, it is just a flaw in how PDAF focusing works. The software will average out those small changes and give you the optimal setting for the lens. It takes me about 20 minutes to do a prime lens and double for a zoom (you do both wide and tele end of a zoom so twice the work). This is not something that is one and done as things change in the lens (the gears do wear some and it can cause changes in the focusing). I do this every October and April which works perfectly for me as one is before the airshow and the other is before spring. I also check it before any big photo specific trips.

While the system is a few hundred dollars, that amount pales in comparison to the money spent on gear or money spent traveling to places to shoot. I spend thousands of dollars every year traveling around just to take photographs, a few hundred to ensure my gear is at optimal performance is really nothing.
08/22/2016 04:42:25 PM · #5
Camera Lens Calibration

How to Calibrate your lens

I recently saw an article about this...never thought about it but it makes sense...I've ordered the focusing paper. I'm sure you could print one off from a computer but I'm lazy and just ordered it.

I'll be curious if it helps you out or not and if anyone else has ever done this....
08/23/2016 01:56:32 AM · #6
have you tried the live view or viewfinder test?
There were known issues with the 70D when they released it 3 years ago.
But only with lenses under f2.0 I use the same lens as yours ,85mm 1.8 and had this problem. Not with my pancake 40mm 2.8 or other lenses.
I adjusted my camera in the local shop here and after their micro adjustments all works fine.
08/23/2016 03:20:40 AM · #7
Thank you for the advice. I knew I could rely on you guys for sound advice on this matter. I will try these suggestions.

@GeorgesBogaert - I have had this camera since 2014 and I have only really noticed this issue fairly recently. I have also read of the known issues but as far as I can understand these issues would have been present from the outset. I am pretty sure I did not experience these issues before.

I don't want to start making adjustments until I am sure what the issue is but guess I can always reset the camera if I balls it up:)

I am keen to upgrade to full frame very soon but if I sell the 70D I want to ensure I am not selling a lemon to any prospective buyer.
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