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10-07-2014, 04:29 AM   #1
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Tamron 70-200mm and K-50

Hy there,

i just bought and Tamron 70-200mm SP AF F/2.8 Di LD IF MACRO to use with my Pentax k-50. Just read some reviews and saw some videos.. and there is a question i have .. is there any ajustment I have to make to the autofocus settings in the camera so the images taken with this lense will come out really sharpe?

Thankx you all

10-07-2014, 04:47 AM   #2
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Not necessarily, adjustments may only be needed if it is front or back focusing with your camera. Like most consumer zoom lenses, your particular lens will not be an extremely sharp lens across all of the focal lengths and apertures to begin with so you will need to practice with it and your camera to get the sharpest it is capable of achieving for each focal length and aperture you use then sharpen further through post processing. Remember though not all photos show well tack sharp.
10-07-2014, 05:32 AM   #3
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QuoteOriginally posted by absnig Quote
is there any ajustment I have to make to the autofocus settings in the camera so the images taken with this lense will come out really sharpe?
Your lens is a premium zoom* and should capable of very good results, though it may take practice. As noted above, there is a chance that you may have to do fine adjustments to the AF system, but I would hold off making any adjustments until you have enough experience shooting with it to determine whether it any are needed. Here are a few bullet points:
  • Your lens will be softer at its widest aperture (f/2.8)
  • Camera motion is a more common source of blurry images than missed focus. Pay attention to holding the camera/lens steady. The shake resistance (SR) feature of your camera works well in general, but is less effective at longer focal lengths.
  • Depth of Field (DOF) is very shallow at longer focal lengths and wider apertures.
  • There are limits to the ability of the AF system to consistently and accurately acquire focus. This is particularly noticeable when the DOF is shallow.
Should you decide to adjust the fine focus at some point, magnified live view is your friend. The same is true for the contrast detect auto focus (CDAF) in live view. Both are slow , but are more dependable for focus than the phase detect AF (PDAF) used by the viewfinder system. Use them to evaluate the PDAF system.


* Despite its moderate price point, I consider the Tamron 70-200/2.8 to be a premium optic based on its test results. Its main weakness is the lack of an in-body AF motor.
10-07-2014, 05:42 AM   #4
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Original Poster
Thankx guys ... will practise a lot...

10-07-2014, 06:05 AM   #5
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Put your lens on a tripod and shot with a remote on time delay to see the real performance of it. I have this lens and I know that is a little difficult to keep it stable at the beginning.
10-07-2014, 06:12 AM   #6
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good tip ... thankx... i suppose its weight its something i have to get used to
10-14-2014, 08:11 AM   #7
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so..the Tamron just arrived.. lets hope its a good investment..:d
10-14-2014, 09:01 AM   #8
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Enjoy your new lens! I got it a while ago and I'm still surprised by image quality every time I lug it with me.


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