02-19-2011, 09:22 AM
[quote name='miro' timestamp='1298043880' post='6225']
Hello PZners,
As already motioned in several treads I have bought Tamron 70-300 VC EF mount.
It is my first telephoto lens and even more It is my first IS/VC lens.
The new focal length opens the new photographic opportunity.
After few weeks of learning I can make some decent shoots. Not toppers but just good enough for beginner.
But I have one technical problem with this Tamron 70-300 VC.
1. I cannot take pin-sharp images handheld with VC enabled. Even at S= 1/200sec
2. I can make pin-sharp images handheld with VC disabled and speed S=1/200sec
I examine the images the RAW images from my 50d at 100%view.
The images with VC are sharp but I have blur = less than 1 pixel in any direction. It worns me that this is VC blur. The handheld blur at S=1/200 must be only in one direction.
I have several technical questions.
1. Is it normal that I cannot take an even one single image with VC, that is as sharp as image taken at tripod + MLU? - Keep in mind that I can take some pin-sharp images handheld with VC-off.
2. What are the tolerances for motion blur introduced by VC/ IS?
3. In which situation I have to switch off the VC?
- Tripod is one of them.
- what about monopod?
- what about holding the lens with hand against three or wall?
- what about holding the lens on top of your backpack or ground.
…………
4. Do I need to switch the VC at higher shooter speeds e.g S=1/1000sec?
Thanks in advance,
Miro
[/quote]
Hello Miro,
1. It is not normal to take blurry images all the time with VC on. If you have a steady hands the VC will create a blur (like on tripod). If S-1/200 can freeze the motion of your object why not compensate for your little hand movement. Have you tried the VC with even slower shooter speeds? and do you use singe focus point in your testing?
4. Basically if the shooter speed exceeds the sampling rate of your VC sensor you don't need VC on. For VR system it sampling is rate 500Hz, so I don't think the VC is much different here.
I hope this is helpful
Kind regard,
Boris
Hello PZners,
As already motioned in several treads I have bought Tamron 70-300 VC EF mount.
It is my first telephoto lens and even more It is my first IS/VC lens.
The new focal length opens the new photographic opportunity.
After few weeks of learning I can make some decent shoots. Not toppers but just good enough for beginner.
But I have one technical problem with this Tamron 70-300 VC.
1. I cannot take pin-sharp images handheld with VC enabled. Even at S= 1/200sec
2. I can make pin-sharp images handheld with VC disabled and speed S=1/200sec
I examine the images the RAW images from my 50d at 100%view.
The images with VC are sharp but I have blur = less than 1 pixel in any direction. It worns me that this is VC blur. The handheld blur at S=1/200 must be only in one direction.
I have several technical questions.
1. Is it normal that I cannot take an even one single image with VC, that is as sharp as image taken at tripod + MLU? - Keep in mind that I can take some pin-sharp images handheld with VC-off.
2. What are the tolerances for motion blur introduced by VC/ IS?
3. In which situation I have to switch off the VC?
- Tripod is one of them.
- what about monopod?
- what about holding the lens with hand against three or wall?
- what about holding the lens on top of your backpack or ground.
…………
4. Do I need to switch the VC at higher shooter speeds e.g S=1/1000sec?
Thanks in advance,
Miro
[/quote]
Hello Miro,
1. It is not normal to take blurry images all the time with VC on. If you have a steady hands the VC will create a blur (like on tripod). If S-1/200 can freeze the motion of your object why not compensate for your little hand movement. Have you tried the VC with even slower shooter speeds? and do you use singe focus point in your testing?
4. Basically if the shooter speed exceeds the sampling rate of your VC sensor you don't need VC on. For VR system it sampling is rate 500Hz, so I don't think the VC is much different here.
I hope this is helpful
Kind regard,
Boris