Yesterday I had a chance to try for the first time the Haida ND 3.0 filter I bought on Amazon with my filter holder. This is this filter:
Haida ND 3.0 HD2505D: http://www.amazon.com/gp/product/B00JAKQ3K2
Sadly all photos I took were not sharp at all when zooming at 100%. I am wondering if I did something wrong or if it might be caused by a defective filter. Here is what I tested:
First I do as if I take a normal shot. It is during the day. I take a test shot in manual mode, auto focus: it is super sharp when zooming 100%. I use a remote shutter release with electronic front curtain and mirror up, just to be sure to exclude all possible cause of blur. There is no wind.
Here is the photo 1: http://i.imgur.com/JXUAnta.jpg
Exposure time: 1/6 sec
Then I switch from Auto Focus to Manual Focus on my D810 body. I place the filter holder on the ring. The Haida filter was already installed on the filter holder. I do this carefully to be sure the camera does not move at all. I run another test shot this time more than 1 min. as you can see, the photo is blurred as if something moved during the shot when you look at the rocks.
Here is the photo 2: https://i.stack.imgur.com/LirnK.jpg
Exposure time: 49 sec
Then I just remove the filter holder, and do not touch to any other button or settings. So my focus is still manual. I take another shot (same time as in step 1) with my remote shutter release. The photo is 100% sharp when looking at the rocks.
Here is the photo 3: http://i.imgur.com/flEtDPp.jpg
Exposure time: 1/6 sec
What I do not understand is that all my photos taken with the Haida filter (as in step 2) are all blurred as if the tripod moved during the shot. When zooming to 100%, both photos from test 1 and 3 are sharp but not the ones from step 2. So it is not an issue on the camera or the focus since with the test 3 I am sure that the camera and its focus did not moved / changed. Also, there was no wind at all.
Do you think I do something wrong ? Or it might be a defective filter ? It is the first time I am using it.
Thanks a lot for your help!
Gear: Nikon D810 with Tamron 24-70 at 70mm
NB: sorry for not including photos directly and better links: Stack Exchange does not allowed me to :-(
All photos have been taken at F8.0 / ISO 100.
Added exposure times for each shot.