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04-16-2012, 08:36 AM   #1
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Focusing with the DA*200 f2.8

Hi all

Recently, and most probably due to the LBA I got one...
I am quite new at it and have a question to those who owns one.

I found that the lens, sometimes, has difficulty to focus where I want. This mainly in the 5 points mode. If I choose the spot on option it's fine so far.
Example if I shoot a bird on a tree that is beyond various branches sometimes in the 5 points mode the focus isn't quite right.
Often, the red dot (which I trust shows the exact focus point) is on the right or the left side, also sometime up, sometime down but never or not too often spot on.
Sometimes/rarely, it's all blurred. I haven't had that with any of my signature lenses

Is this a normal behaviour ?

Many thanks for you're help

04-16-2012, 08:53 AM - 1 Like   #2
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Yes, that is a problem with any and every lens/camera combo, since the camera sometimes thinks you want to focus on the branches. You selected one of the most difficult scenarios. Use spot mode.

Last edited by Giklab; 04-16-2012 at 12:42 PM.
04-16-2012, 08:59 AM   #3
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Plus 1

and also fine tune manually ( the DA*200 supports quick shift focus)
04-16-2012, 09:55 AM   #4
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Also be aware that the red AF focus points are a lot smaller then the area covered by the AF sensors. For instance, the center AF is a cross-type sensor with the + almost the same height/width as the Spot Meter circle. The other + sensors are similiarly sized.

Trying to pick and choose edges to focus on that overlap objects at different distances can get quite annoying...even without the camera trying to decide by choosing between numerous focus areas. As mentioned it is often easier to pick one sensor and compose around it.

04-16-2012, 11:47 PM   #5
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So apparently its normal.
I was just asking this because with none of the lens of my signature I had this kind of behaviour.
There all spot on while on the 5 points setting.
It might be due to the fact that the 200mm is much larger ?

Thank you all for you're feedbacks
04-17-2012, 03:20 AM   #6
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I recommend that you ditch the 5 points focus and use SINGLE in the case of this lens. It is likely that your subject will be some distance from you and you can point at what you want to focus on and then re-frame afterwards. It's unlikely that focus will change due to minute camera movements in this situation. Just make sure that you keep your finger depressing the shutter button 1/2 way whilst framing or the camera will refocus (if the shutter button is set to allow AF of course)
04-17-2012, 05:38 AM   #7
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Wilco to that Bossa and thanks for that suggestion
04-17-2012, 05:54 AM   #8
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QuoteOriginally posted by ide508 Quote
It might be due to the fact that the 200mm is much larger ?
No, as Giklab points out, it's the nature of the subject -- with a bird amongst branches there are too many potential focus targets. Take Bossa's suggestion and make a user mode with those settings so you can easily change back and forth. Also consider disabling the AF with the shutter release button in that mode, using the AF button instead.

04-17-2012, 07:18 AM   #9
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QuoteOriginally posted by ide508 Quote
So apparently its normal.
I was just asking this because with none of the lens of my signature I had this kind of behaviour.
There all spot on while on the 5 points setting.
It might be due to the fact that the 200mm is much larger ?

Thank you all for you're feedbacks
The issue increases with longer lenses because they have shallower depth of field. The intelligence ??? in the focusing system hunts for
a location where all the sensor spots are in focus---but no such place exists due to the shallow depth of field so it hunts for a while looking for what doesn't exist and then gives up. Longer and faster lenses need to be used in the spot mode.
04-17-2012, 07:48 AM   #10
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QuoteOriginally posted by rvannatta Quote
The issue increases with longer lenses because they have shallower depth of field.
The lens is a 200mm (FOV of a 300mm on your camera) AND an f/2.8.

QuoteQuote:
Longer and faster lenses need to be used in the spot mode.
Exactly. None of your other lenses have such shallow depth of field as this one, so for example with the 40mm 2.8 you could have the entire tree sharp in focus at (say) 30m or so.
04-17-2012, 11:44 AM   #11
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I agree, use single spot mode. I use a 200mm Vivitar daily and have no trouble. Mine is not autofocus, but the focus confirmation is very accurate set for single center spot, and when I was using the AF kit lens single seemed to work a lot better too. Using 5 or more it would "hunt" forever, using single it never gave me any trouble. So I don't even consider multiple spots any more, even for my point and shoot cameras. I keep everything set on single center spot.
04-17-2012, 11:55 AM   #12
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Thank you all of you for helping me getting the best of that great lens !
04-23-2012, 08:33 AM   #13
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Almost two weeks that I own this lens, lots of pictures (training phase) done, but one more question for the road...

Sometimes, rarelly, when I aim to another spot than the last shot, I can hear the AF / SDM hunts for the good focus but stop somewhere giving me an all blurred screen. I have to re press half way the button and it's then spot on.

Would this kind of behaviour be normal to you all ?

Thank you
04-23-2012, 09:10 AM   #14
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I've had that happen with other lenses occasionally (usually in lower light or where the focus point can be confused) Don't own the DA* 200 but i don't imagine it is exempt
04-23-2012, 11:07 PM   #15
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Thank you eddie for that return.
I feared that it "might" be a sign of SDM failure...
Cheers
Bernard
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