Hi everyone.
Maybe one of you has a good explanation for why my image quality is very bad when I am shooting with a long focal length (300 mm APSC) while using a ND-filter. Please see example below:
Looks like (very slight) camera shake to me. Probably the tripod isn’t 100% stable.
Can you share a 100% crop covering the lighthouse and the pier? Both shots.
Sure. both crops are roughly 1920 pxls on the long side.
I’m pretty sure that it is indeed camera movement. Look at the upper platform and the white patch above the door. The platform is too thick and the patch too tall, suggesting vertical motion. The patch leans right and the platform also has an angled edge it shouldn’t have, which would be from horizontal movement.
Here’s a denoised version, where it’s a bit more obvious:
Thanks. This helps a lot for future projects.
Could it be the ibis trying to fix a non existent movement(because of the tripod)?
The lens says that it detects this situation and adapts accordingly. Never know if that is true.
It is unlikely to be the ND filter per se, but you can just take the same photo with and without it if you want to test that.
I would agree with @Donatzsky, it looks like camera shake.
What body and lens are you using?
It is a variable ND-filter … maybe that makes a difference.
I am using a Fuji X-S10 with the 70-300 lens. Here is the image without and with ND-filter (both cropped to 1920 pixls):
Did you have image stabilisation switched on?
Opinions differ, but the general advice seems to be to turn it off while your camera is on a tripod.
It was all turned on (IBIS and OIS). On the shorter focal length it worked well …
I wonder whether it is not kicking in with a short focal length, but something is forcing it to kick in (air movement?) at a longer focal length and the feedback is leading to blur.
I might just get my 200-500 out and try this out. I can’t put a filter on it, but I could wind the ISO rating right down.
How are you triggering the exposure?
The manual for your camera should describe if you should turn off the ibis in a tripod. Did you check?
Can the tripod/head handle the weight of the setup to avoid vibrations?
Yeah, one that I hadn’t considered. How is the support done? Is the camera screwed to the tripod, or the lens? If it is the former, then the turning force might cause the stabilisation to kick in.
EDIT: Having waxed eloquent elsewhere on science and theories, I seem to have got over-fond of my own hypothesis, that it is the stabilisation that is causing the problem.
I see a few tests that could help to diagnose the problem:
That’s a significant difference in shutter speed, so yes, it has a big impact.
Newer systems may well have it sorted (not sure), but for older systems the IS operates on the assumption that there will be movement and get confused when there isn’t.
Shorter/wider focal lengths are less likely to show camera shake. Nothing new there. As a rule of thumb, without IS, the slowest shutter speed you can use hand-held is the reciprocal of the focal length. So with a 35mm lens the slowest would be 1/35s and for a 300mm lens it would be 1/300s.
I haven’t read every word in this post so apologies if I repeat any suggestions here. But stabilisation is generally not needed with a steady tripod and there can be shake caused by mirror release. I would use a 2 sec delay to reduce the risk of this. Also if there was wind your tripod might not be as steady as you thought. A remote to trigger a tripod held camera is also a good idea. Touching the shutter button with your finger shakes a tripod. Your image looks like camera shake to me. But maybe mirror shake or image stabilisation shake (which I have definitely seen over the years). Good luck solving the issue.
3s at 300mm is really pushing it, even on a tripod. Any air current or even the earth’s rotation might cause blur at these settings.
The image looks like motion blur to me. I’d guess that the filter pushes you towards longer shutter speeds, and the longer shutter introduces more motion blur.
I agree it looks like motion blur.
Image stabilization may be better for low-frequency movement (eg hand-held) rather than high-frequency movement (eg on a vibrating tripod). I haven’t experimented with this.
How stable is the tripod on that particular ground? I often use a tripod on grassy ground. This is useful for keeping the camera in the same place, but isn’t good for long focal lengths and long exposures, because the tripod bounces on the ground.
And if you are on constructed ground with your tripod, don’t move during exposure of the photo.
Could well be blur, but anyway variable nd are two polarizer or something similar and i have always found them bad in term of image quality.
Also in my experience polarizers with longer focal lenghts tends to produce not so sharp images, especially cheap ones. For nd i use an haida 1000 that doesn’t seem that bad to me and at the times it was cheap enough.
A nice test would be to redo some shots with more light no wind and so on in order to better investigate the problem.
