All blurry shots...

mikebeecham

mikebeecham

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Hi guys,

So, I decided to take my shiny new 50mm 1.4 USM lens out for a trial today and took a shed load of snaps. The weather was great, bags of sunshine, blue sky etc...light was good.

Taking the shots was great. I set the camera to AV, ISO to 100, and opened up the aperture to the full 1.4 to get loads of lovely blurred background, but when I get the shots home, all but one of the shots was blurry in the foreground as well.

Any ideas why this might be? Was I simply in too much of a rush to take the shot and moved off too quick, or is something more fundamental taking place that I need to be mindful of?

Thanks for the help!
 
At f/1.4 of course you'd get both blurry foregrounds as well as backgrounds. Depth of field extends in front of the focused point, as well as behind it. Check it on this DoF calculator http://www.dofmaster.com/dofjs.html
 
Without opening these up large, I'm not sure that I can see the problem here. Other than the signpost shot (looks like focus was right on the end of the sign), they all appear to have a sharp subject and blurred background.
 
They look as I'd expect. The DOF is about 2mm at f/1.4. All shots have a 2mm or so sharp art and the rest is OOF as expected.

The focus isn't in the right place, but it is there.
 
Hi guys...so (apart from signpost) the others are probably more a case that I focussed in the wrong place? For example, I wanted more of the bench to be in focus, rather than the arm only...is this more about closing down the aperture a little, maybe to 3+?

Sorry, still all kinda new at this!
 
mikebeecham said:
Hi guys...so (apart from signpost) the others are probably more a case that I focussed in the wrong place? For example, I wanted more of the bench to be in focus, rather than the arm only...is this more about closing down the aperture a little, maybe to 3+?

Sorry, still all kinda new at this!
Click to expand...

Yep, pretty much. Closing the aperture down will increase the the depth of focus.
 
mikebeecham said:
Hi guys...so (apart from signpost) the others are probably more a case that I focussed in the wrong place? For example, I wanted more of the bench to be in focus, rather than the arm only...is this more about closing down the aperture a little, maybe to 3+?

Sorry, still all kinda new at this!
Click to expand...

Check your DoF on the calculator I linked to above.

Also, this good explanation of the concept of DoF was posted on another current thread http://photo.andysheen.co.uk/technical/depth-of-field-and-what-affects-it-explained/
 
Mike, assuming you were using autofocus and not manual, how were you setting the shots up?
Were you changing the AF point or using the centre point to focus and recompose?
 
mikebeecham said:
...is this more about closing down the aperture a little, maybe to 3+?
Click to expand...

When you say 3+, are you mistakenly meaning exposure compensation?

Instead of using f/1.4, set it to (for example) f/11 and there'll be less blur, assuming you keep the distance between you and the bench the same. Then go up really close and shoot it at f/11 and compare the amount of blur. Then read the links posted by Richard if you need to understand why the different amounts of blur can occur at f/11 whilst shooting the same subject.

Personally, I would only use f/1.4 if trying to be particularly creative or in low light situations, in all other situations I'd choose much narrower apertures.
 
f/1.4 and being close to subject is going to be pretty limiting, just because your lens has a large aperture doesn't mean you have to use it (realise you were playing with it so may not be relevant!)
However it is great if you still want low DoF but are not as close to the subject as other lenses won't be able to give you such 'lowness'
 
Wozzaaah said:
Mike, assuming you were using autofocus and not manual, how were you setting the shots up?
Were you changing the AF point or using the centre point to focus and recompose?
Click to expand...

Well, to be honest, I just took the camera out and thought I would try and just 'point and shoot'. So, really I just set the camera to AV, set the aperture to 1.4, then went in and took some shots of items of interest.

I didn't take tripod or anything like that.

Mentioned on here was the idea of setting the aperture to f11. If I understand it right, though, that means the shutter speed will be much slower and subject to shaking and blurring just because of me holding the camera?

If I understand that correctly?
 
mikebeecham said:
Mentioned on here was the idea of setting the aperture to f11. If I understand it right, though, that means the shutter speed will be much slower and subject to shaking and blurring just because of me holding the camera?

If I understand that correctly?
Click to expand...

more or less correct.

however, under direct sunlight, using Sunny 16 rule and considering this is winter in UK, I'd estimate f11 ISO100 1/100 will give you a good exposure. So shutter speed won't be much slower and still be okay to hand hold.
 
mikebeecham said:
Mentioned on here was the idea of setting the aperture to f11. If I understand it right, though, that means the shutter speed will be much slower and subject to shaking and blurring just because of me holding the camera?

If I understand that correctly?
Click to expand...

That is where ISO comes into play, if your shutter speed gets slower than 1/60 hand shooting then try upping the ISO to bring the shutter speed back down, but it all depends on how good the light is

But you should easily be able to shoot at mid range apertures in good light without needing to go to the extremes of f1.4

As said above, get a DoF calculator and work out how much of a particular shot is going to be in focus, you will soon learn to judge it for yourself
 
do a test on something similar to the bench focus in the middle and then take a seriesof shots starting at f1.4 all the way to f22 to see how the depth of field changes and there fore how that particular lens is affected by it.
 
You got what I'd expect to see, but when the DoF is that shallow, what you focus on is really important.

You can't really just point it at random subjects and expect to produce an interesting photograph. The object focussed on has to be the point of interest.

So; either these are all perfectly focussed images of badly chosen subjects, or badly focussed images. It really depends what it was you were focussing on?

And if you start using that lens at f11 (as some have suggested), you've completely missed the point of it. Because at f11 it won't give you a much better photo than your kit lens would at f11:cuckoo:
 
F/11 was suggested for comparison purposes only, use whatever setting gets you whatever shot you're after - be it 1.4 or 22.
 
Phil V said:
You got what I'd expect to see, but when the DoF is that shallow, what you focus on is really important.

You can't really just point it at random subjects and expect to produce an interesting photograph. The object focussed on has to be the point of interest.

So; either these are all perfectly focussed images of badly chosen subjects, or badly focussed images. It really depends what it was you were focussing on?

And if you start using that lens at f11 (as some have suggested), you've completely missed the point of it. Because at f11 it won't give you a much better photo than your kit lens would at f11:cuckoo:
Click to expand...

With regards to focussed subjects, the latter is case. For example, I was hoping to get as much of the bench in focus with the other benches out of focus. Clearly didnt happen. The signpost was supposed to be in focus (obviously!)

Thanks
 
mikebeecham said:
With regards to focussed subjects, the latter is case. For example, I was hoping to get as much of the bench in focus with the other benches out of focus. Clearly didnt happen. The signpost was supposed to be in focus (obviously!)

Thanks
Click to expand...

If it was obvious what you'd been trying to achieve, you wouldn't have a page of guesses as to what you might be trying to achieve;)

To achieve what you want, you'd need a smaller aperture, check what's in focus with the DoF preview button. It seems a bit old school, when everyone talks about DOF tables and stuff, but your camera was designed with everything you need. There's no need to be guessing it's either 1.4 or 11, it might be f2 or 2.8.

It looks like if you'd have focussed on the word 'walk' all the writing on that finger of that sign would have been within the DoF (ish), it looks like you focussed on the end of the sign.
 
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Phil V said:
If it was obvious what you'd been trying to achieve, you wouldn't have a page of guesses as to what you might be trying to achieve;)

To achieve what you want, you'd need a smaller aperture, check what's in focus with the DoF preview button. It seems a bit old school, when everyone talks about DOF tables and stuff, but your camera was designed with everything you need. There's no need to be guessing it's either 1.4 or 11, it might be f2 or 2.8.

It looks like if you'd have focussed on the word 'walk' all the writing on that finger of that sign would have been within the DoF (ish), it looks like you focussed on the end of the sign.
Click to expand...

That's not quite true Phil, at least not as far as the viewfinder is concerned. The DoF you see there is not accurate at low f/numbers and most standard focusing screens will not show anything lower than about f/5.6 (for complicated optical reasons) and at higher f/numbers the image gets so dark you can't see anything much at all.

However, live view comes to the rescue and that shows DoF exactly as in the final image, after pressing the lens stop-dwon button of course. Zoom in and scroll around to get a clearer look.
 
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There's nothing unexpected in these images. Everything is working properly, it's just the point of focus that you've got wrong. If you're using apertures as large as 1.4 you need to nail the focus and point of focus. Be specific and precise with what your focusing on.

To understand what's going on and how shallow the DOF is, get a 30cm ruler and lay it facing away from you (so the 1cm is close to you and the 30cm is far away). Take 2 steps back and focus on the 15cm mark. Then look at your image and see what's in focus and what isn't. You'll start to understand how it all works.
 
also at 1.4 you must move your focus points in the camera and do the smallest re composition possible.
 
Thanks for all the advice guys...seems I have much to learn and get to grips with.
 
To be honest in most of the photos the sharpest part of the image seems to be the one closest to the camera, for example in the wall shot where you do not want it to be.

This suggests to me that you are using all the AF points and the camera is deciding where to focus, if this is the case try setting the camera to use just the centre point and take charge of the focusing your self.
 
craftysnapper said:
To be honest in most of the photos the sharpest part of the image seems to be the one closest to the camera, for example in the wall shot where you do not want it to be.

This suggests to me that you are using all the AF points and the camera is deciding where to focus, if this is the case try setting the camera to use just the centre point and take charge of the focusing your self.
Click to expand...

Thanks for the suggestion Crafty. In fact, yes, I have it on all points, mostly because I dont know any better :). Would it be a case to have it on centre-point normally, unless you're looking to get more of the 'context' but keep the focus on another point other than centre?

Cheers.
 
I always shoot centre point mode, and use the "shoot recompose" methed in 90% of my hand held shots, but for extreme short DoF like with your 1.4 set at 1.4 then you should probably be selecting the appropriate focus point as using the focus recompose method the focal plane may shift during the recompose

IMO all points mode is for point and shoot cameras (or if you are letting someone else use your camera who is used to point and shoots :lol:)
 
rpsmith79 said:
I always shoot centre point mode, and use the "shoot recompose" methed in 90% of my hand held shots, but for extreme short DoF like with your 1.4 set at 1.4 then you should probably be selecting the appropriate focus point as using the focus recompose method the focal plane may shift during the recompose

IMO all points mode is for point and shoot cameras (or if you are letting someone else use your camera who is used to point and shoots :lol:)
Click to expand...

Hi mate! Not sure I'm familiar on the 'shoot recompose' method. Is there a link I can look at for this?

Thanks

(I'm all about the learning!!)
 
wuyanxu said:
The technique:
http://photo.tutsplus.com/articles/theory/mastering-two-alternate-focus-techniques/

The possible problem, with a 1.4 lens
http://digital-photography-school.com/the-problem-with-the-focus-recompose-method

Unless I am shooting 85mm f1.8, I always focus-recompose. with the 85/1.8, I move focus point to avoid being out of focus
Click to expand...

Great tutorials the explain both sides of the argument. I guess the obvious thing is to try it and see what works! Since i've just bought this 50mm 1.4, I'm going to be pretty much using this all the time since I wont be able to afford another lens for a while to come....might as well get used to it ;)

It looks as though there's some wisdom in also bringing the focus to a back button instead of a half-press shutter. Also wondering whether metering lock on the shutter is a good idea or not.
 
Definitely take control of which focus point to use.

Back button focus is a must for me, its the only way I feel in control of the camera.

Whether or not to use exp lock depends on circumstances, I use it most of the time but switch it off sometimes for Motorsport.
 
Phil V said:
Definitely take control of which focus point to use.

Back button focus is a must for me, its the only way I feel in control of the camera.

Whether or not to use exp lock depends on circumstances, I use it most of the time but switch it off sometimes for Motorsport.
Click to expand...

I tried out the back button today and YES! It feels like you get much more control of the camera. Been reading the 'focus and recompose' article but can't get my head round the fact that the focus remain on the focal point while you recompose, despite having taken your finger off the focus button.
 
mikebeecham said:
I tried out the back button today and YES! It feels like you get much more control of the camera. Been reading the 'focus and recompose' article but can't get my head round the fact that the focus remain on the focal point while you recompose, despite having taken your finger off the focus button.
Click to expand...
haha, same.

I've set back focus button to be AF-stop instead. shutter button works like before, but if I want it to stop hunting, I can hold the AF-stop button to stop AF.

I focus-recompose most of the time, just flick, half press and then flick to shoot. Once you get used to it, it's almost second nature.

But do aware of the change in focal plane when shooting at f1.4.
 
wuyanxu said:
The technique:
http://photo.tutsplus.com/articles/theory/mastering-two-alternate-focus-techniques/

The possible problem, with a 1.4 lens
http://digital-photography-school.com/the-problem-with-the-focus-recompose-method

Unless I am shooting 85mm f1.8, I always focus-recompose. with the 85/1.8, I move focus point to avoid being out of focus
Click to expand...

The potential problem with focus-recompose technique certainly exists, in theory, but is generally greatly exagerated. In that link above, the example given is daft and the maths is way out - it's actually a fraction of the focus shift quoted.

Focus-recompose is only a problem when a) you are shooting very close, b) the sharp zone needed is a long way off-centre - these two factors combine to create a large angle of movement when recompsoing. And c) when you're at a very low f/number and DoF is super-shallow. Even then when all three factors are present, the most usual cause of focus shift is camera or subject movement between focusing and shooting.

mikebeecham said:
Great tutorials the explain both sides of the argument. I guess the obvious thing is to try it and see what works! Since i've just bought this 50mm 1.4, I'm going to be pretty much using this all the time since I wont be able to afford another lens for a while to come....might as well get used to it ;)

It looks as though there's some wisdom in also bringing the focus to a back button instead of a half-press shutter. Also wondering whether metering lock on the shutter is a good idea or not.
Click to expand...

With all AF points active, the focus will always go to the one at closest distance, as it has done with the shot of the signpost. Not always what you want ;)
 
Does OP remember exactly where he was focusing in these images? Because unless you really don't know your camera's focus points, you were probably on point, where you wanted to be, but the lens may well be heavily front focusing!

I don't get why people start recommending back button focus and all that, there's nothing wrong with straight forward half shutter press to focus - I've been doing it years.

Anyway, I just sent back a lens that was missing focus too, also a 1.4, and I know it's nothing to do with my technique as I've also ran tests on a tripod with still targets. Don't take the chance that it might not be the lens, if it's missing focus all the time it probably is. Better to change it now.
 
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