Newbie feeling very deflated focussing issues

[Phil V]

This wasn't using back button focus. I followed to the letter what someone had suggested earlier and used a tripod so should be no user error. Following the instructions I focused on one area on the text. Using live view the text is clear when viewed at 100%. Using the viewfinder at same aperture when zoomed in this isn't as clear therefore I was told it is the relationship between camera and lens?

I completely understand your frustration, however you're posting an example to 'prove' it's not focussed where it's supposed to have, but only you know the bit of text on which you focussed

I'm not saying you're incorrect, I'm saying how would anyone else verify?

If the lens is out slightly (not unknown) then Canon will fix it (for a fee) on bodies where you can't do it yourself.

But the fact that they build bodies with these adjustments tells us that manufacturing tolerances mean that there'll be 'bad' matches between a camera and lens.

Some people have a history of lots of 'bad' lenses, others are either less picky or very lucky depending on your world view.

In my experience, I've had too many EOS lenses to count and over 20 Canon cameras (8 digital), and just one lens* that misbehaved on 2 different bodies, but was perfect on 2 others.

*it didn't help that it was my 17-55 everyday workhorse lens

 

[Katie Skelton]

Apologies - the focus point was on the line underneath the red subheading where the word 'depth' was. It has come out clear (it looks to me) using the live view but not (as clear) using the viewfinder. It was not moved or refocused at all.

 

[the black fox]

My post wasn't intended to cast doubts on your abilities ,but your initial posts come across as a you being a complete beginner ,and to introduce things such as BBF coupled with a short lens imho is not the way to progress .so apologies if taken the wrong way it was not intended to sound like that .
It's extremely hard to gauge someone's skill level via a forum .so I'll now withdraw from this thread

 

[Katie Skelton]

No sorry I'm not a 'complete' beginner but I am getting frustrated in this lens or what I could be doing wrong. However just followed step by step advice from someone else to check it which didn't involve my eyesight really....

 

[drounding]

Just my opinion, although I'm no pro mind...

It is very difficult to get perfect focus every time with such a shallow depth of field, even though you have the camera on a tripod. There are differences in the focus methods between live view and through the viewfinder. Live view is usually more accurate but slower and you can zoom, using the viewfinder is faster but possibly less accurate - just what you are experiencing. I think (although I stand corrected by those that may know better) that live view uses the sensor to focus rather than phase detection, as it is through the viewfinder. It is common to see differences, especially with shallow depth of fields.

The fix would have been to try micro adjustments but as that's not available on your camera then personally I would accept it and move on, there's so much more to taking a great portrait than just perfect focus. Try separating the subject further from the background to keep the background blur, up the f stop to increase the depth of field and get a better probability of catching focus, keep the shutter speed quite high to help minimise the influence of your own movement, and increase your iso if you need more light.

Most importantly take lots of photos and view the images with an artistic eye rather than a technical one. A picture needs to tell a story not just show the sharpness of the eyes.

 

[CraigDHD]

Hi Katie it sounds like there probably is a variance between the lens and body. In this instance though the way you've set that test up may present problems as the book is not flat so you can see falloff across the page of text. As Phil has stated the AF module used through your viewfinder is not as precise as it sometimes presents itself in the viewfindel at looks at an area around that spot for the highest area contrast and locks on to that. As the page is not flat with the sensor here it may be just locking on to a different point from the live view. There's some great guides online on how to calibrate your lens follow one of those to the letter and it will show whether your lens needs calibrated or not.

If your lens is out the next ideal step would be to test some other lenses, if you know anyone else who has a canon camera see if you can borrow some other large apperture lenses and test the same way. If all the lenses have issues there's possibly an issue with your camera, if it's under warranty contact canon and they may be able to fix it. If it's out of warranty again as Phil advised repair centres can calibrate your body and lens for a fee.

If it's just your lens that is out there's a few things you can do next, the not ideal but simplest solution is find the minimum apperture that gives you reliable depth of field and live with it 1.8 looks great for a while but for shooting kids it's unreliable and is always gonna lead to a lot of missed shots even when it is accurate so a slightly smaller apperture can be a good idea anyway. If the lens was bought new send it back for a replacement. If the lens is not new trade it for a different lens. Alternatively if shooting wide is going to be a real priority a body upgrade may be worth considering, that doesn't mean you need the newest most expensive body but trading in your current body for a slightly older more capable one with the features you need might be a good option as if you are going to be using fast lenses wide open a lot will benefit from fine tuning .

 

[seriousrikk]

OK, my first suggestion is to stop using back button focus.

It is no more accurate that using the half press of the shutter in your situation, but could very well introduce other issues.

I know on my cameras if I use the back button to focus I have to specifically uncouple focussing from the shutter half press. Have you / can you do this on yours already? It could be that the half press is still engaging focus even though you had already focused with the back button, causing a slight movement.

Also, and this is just my opinion, but the ergonomics of using back button focus on a camera without a dedicated button is pretty awful. Don't rule out the possibility that this is also having a bit of an impact.

 

[ABTog]

Lots has been said about technique and possible issues with gear.... but I think what you've got is actually a pretty good photo.

This one you've shot is good. The composition is good, the light is good, the child has given you a good expression, the depth of field (and bokeh/blurry background) is very nice.

2 by Katie Skelton on Talk Photography

Don't beat yourself up about it not being completely sharp. In this digital age, people are obsessed with sharpness, don't get drawn into that. It doesn't need to be completely razor sharp and if it did need to be that sharp, you'd shoot at f4.
Take a read of this article:
http://mikeonthestreet.com/2015/07/19/3-reasons-sharpness-doesnt-matter-in-photography/

I don't think back button focus is the problem (though I don't use it myself). If you use focus-recompose (whether using BBF or not) then by it's very nature you're moving the camera between when you focus and when you taken the picture. In that small space of time the camera has moved and it's quite possible that your subject has leaned a centimetre back or forward, as will you, particularly if you're crouching (like this shot, I imagine). That centimetre change in distance from camera to focus point can, at f1.8 or f2 be enough to put the image very slightly out of focus.
This is one reason I use focus point selection, rather than focus recompose. That way I'm not moving the camera in between focussing and shooting.

Frankly kids move, a lot and getting a camera to focus on a moving target is tricky, (this was the reason I got a DSLR in the first place as a bridge camera wasn't cutting it.) if you are using the Canon 50mm f1.8 Mk2, then the focus motor is really slow, so it's not a great lens for following moving objects. The newest version of this lens, the f1.8 STM is much faster at focussing. I upgraded to the 50mm f1.4 partly due to the fact that the focus motor was much faster (the STM lens wasn't out at that time).

So
1) don't beat yourself up about sharpness
2) quit pixel peeping (zooming to 100% and more),
3) look at the image as a whole, not just a tiny zoomed segment and ask, does the image work? does it capture a moment?
4) try not to use focus/recompose, see if that helps
5) take more photos, enjoy it
6) learn stuff, try new ideas,
7) repeat step 5

I would also suggest you get yourself started on editing software of some sort, but be aware of not overdoing the editing, don't over blow the saturation, vibrant or sharpening, going too far only looks weird.

You're doing fine, enjoy photographing your kids.