Focus not catching...

RacingSnake

RacingSnake

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Gavin
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Hi guys, I've had a search on here, but couldn't see anything particularly relating.
had an odd, and annoying issue this morning.
We had 2 red kites sitting in our garden this morning, lovely light on them, but for the life of me it wouldn't focus.
Well, it looks like it would, but the pictures just weren't sharp, when similar distance/subject type shots in the past have come out fine.
Now I've downloaded and looked at the photos, I can see that no focus points are highlighted, but I cannot understand any reason for it.
Any ideas to check?
tripod mounted
Canon 1dx2
600f4 + 2x TC
1/1250 @ f8, Auto ISO
both centre spot or array focusing had the same result?

Even manual focus couldn't really sharpen it up?

Capture.jpg
 
My initial thought was how close were you in either circumstance?

The bare 600mm has a min focus distance of 4.5m/14.77ft though I could not readily find the figure for the lens with the X2 TC attached......but surmise that it could be at least double that for the bare lens.

As in all things, only when you can eliminate user error (camera settings and/or say too close to focus) think about equipment problems???
 
According to google maps 'measure', it'll be about 50m away.
I've taken similar shots many times, but this morning it would 'appear' to focus, but then be slightly off (which I couldn't refocus with manual).

I did have a similar experience the other night taking a photo of the moon, but that did 'finally' focus on it.
 
Box Brownie said:
My initial thought was how close were you in either circumstance?

The bare 600mm has a min focus distance of 4.5m/14.77ft though I could not readily find the figure for the lens with the X2 TC attached......but surmise that it could be at least double that for the bare lens.
Click to expand...
The minimum focus distance with a 2x TC is actually 50mm longer that that of the lens alone. The minimum 'working distance' (from the lens to subject) is unchanged and hence the MFD (sensor to subject) is increased by the physical length of the TC.
 
looking at you picture to me it looks as if there are too many focus points at different distances, so the camera has to take an average. This may easily be sorted by using spot focus instead
 
That's a tough one for any focusing system (Except manual obviously.:)) I would suggest single point focus, preferably the central one, and lock on the eye or which ever part is free of branches.

Edit. Good to see you got a good clean shot...I see loads of Red Kites when I see the in-laws in Chesham Bucks'.
 
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realspeed said:
looking at you picture to me it looks as if there are too many focus points at different distances, so the camera has to take an average. This may easily be sorted by using spot focus instead
Click to expand...
Graham W said:
That's a tough one for any focusing system (Except manual obviously.:)) I would suggest single point focus, preferably the central one, and lock on the eye or which ever part is free of branches.

Edit. Good to see you got a good clean shot...I see loads of Red Kites when I see the in-laws in Chesham Bucks'.
Click to expand...

@RacingSnake did say this in his OP
"both centre spot or array focusing had the same result?"
So it would seem he had tried the single central focusing 'spot' ;)
 
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Thanks guys, I'm heading out in a minute to do some more testing - maybe some less cluttered area.

but yes, I did do centre spot, bang in the middle of the bird and it just wouldn't lock on.


Capture2.JPG
 
It's quite possible that there's a spec of dust on the centre spot's focusing pair so worth trying one of the off-centre points to see if it locks on.
 
Canon Bob said:
It's quite possible that there's a spec of dust on the centre spot's focusing pair so worth trying one of the off-centre points to see if it locks on.
Click to expand...
Good plan, I tried without the converter, and it appeared to focus better, but the lighting was different, subject was closer etc.
I'll give this a go though, as the same bird in the tree a couple of weeks ago was fine :|

sk66 said:
Blow out the mirror box... in particular the floor where the AF module's field lenses are.
Click to expand...
Will do :)

Have also just updated the firmware (was way out of date), I know that won't explain an issue, but be interesting if it does anything!
 
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