The GetDPI Photography Forum

Great to see you here. Join our insightful photographic forum today and start tapping into a huge wealth of photographic knowledge. Completing our simple registration process will allow you to gain access to exclusive content, add your own topics and posts, share your work and connect with other members through your own private inbox! And don’t forget to say hi!

More then I bargained for

P

pieter

Guest
I shot a couple of pictures on the 1st of a small clump of Iris reticulata we have in our front yard, using my 45-200 and was not overly thrilled with the sharpness I saw, or rather didn't see. Then it dawned on me that I had overlooked to switch off the IS on the lens and figured I'd better do another couple of shots the next morning. Not only was the overall sharpness substantially better, I also got the bonus of some fresh precipitation on them. This was shot on an old Minolta TR1 table top tripod at about F11 and manual focus, using a quick conversion of the RAW file in Silkypix and knock back the exposure value by about 2/3 of stop to increase the overall colour saturation.

 

Tullio

New member
...Then it dawned on me that I had overlooked to switch off the IS on the lens...
I'm not sure I understand your comment. Are you saying that once you switched OFF the OIS you obtained a sharper image? If so, it does not make much sense as the IS should help with image sharpness, not hurt. Just curious.
 

Arjuna

Member
I believe that the picture was taken on a tripod, and as I understand it, if you are shooting on a tripod, IS should be turned off, as otherwise it degrades the image.
 

Pelao

New member
I don't have a Panasonic lens with IS, but since he was using a tripod, perhaps it is better to have the IS off? This is the case with the IS for some other brands.
 

Tullio

New member
I always failed to understand that concept. Why would the IS affect the image if the camera is on a tripod? The camera should be very steady on a tripod and that should be no different than having very steady hands when shooting hand held. The way I see it, the OIS compensates for camera shake. If there is no shake, the OIS should do nothing because there is no need to compensate for anything. Why would it degrade the image in terms of sharpness? A lot of times I position myself in ways that it's almost like having the camera on a tripod, so steady it is. Should I switch the OIS OFF in those instances? Just trying to understand the rational behind it.
 

photoSmart42

New member
I always failed to understand that concept. Why would the IS affect the image if the camera is on a tripod?
As I see it, the OIS isn't perfect, and it's designed to compensate for actual movement characterized by someone holding the camera in their hand. Because it's not infinitely capable of compensating for very small changes, it tends to over-compensate for small movement with larger adjustments. So with the IS set on a 'stable' platform, you end up with the IS itself causing distortions because it's over-compensating for whatever small movement exists in the tripod.

Ideally you'd have a noise threshhold in the motion detector to ignore small movement beyond what the IS can compensate for, and it's possible that newer cameras have something like that, but the old conventional wisdom stuck based on early experiences with IS and tripods.

Look at it this way. Let's say the IS can compensate for movement in 0.2 mm increments (it's a digital system). For movements greater then the 0.2 mm, the IS can deal with it effectively. For movements smaller than 0.2 mm, the IS sees those and thinks it needs to compensate, but it can still only make corrections in 0.2 mm increments. So your 0.01 mm movement perceived b your camera sitting on a tripod now turns into a 0.2 mm oscillation as the IS tries to and fails to compensate for the smaller movement.
 

Tullio

New member
Interesting...thanks for the explanation. At least it makes a bit more sense now. Cheers.
 

vincechu

New member
I shot a couple of pictures on the 1st of a small clump of Iris reticulata we have in our front yard, using my 45-200 and was not overly thrilled with the sharpness I saw, or rather didn't see. Then it dawned on me that I had overlooked to switch off the IS on the lens and figured I'd better do another couple of shots the next morning. Not only was the overall sharpness substantially better, I also got the bonus of some fresh precipitation on them. This was shot on an old Minolta TR1 table top tripod at about F11 and manual focus, using a quick conversion of the RAW file in Silkypix and knock back the exposure value by about 2/3 of stop to increase the overall colour saturation.


Wow what an amazing image, it makes me wonder if I should have bought the 45-200mm to go with my G1 instead of the more expensive 14-140mm lol
 
P

pieter

Guest
I'm not sure I understand your comment. Are you saying that once you switched OFF the OIS you obtained a sharper image? If so, it does not make much sense as the IS should help with image sharpness, not hurt. Just curious.
You'll find when you check the manual that it is recommended to TURN OFF IS when using a tripod :).
 
Top