What have I done here

[matt34]

Hi All

I was out taking some night shots 2 nights ago about 9pm and was madly snapping away before the clouds came rolling in. When I got home I spotted this shot, this is staright of ot the camera just used Lightroom to resize for here. Not sure what I've done any ideas?

Canon 6D Samyang 14mm f2.8 ISO6400 for 20 seconds

- may have bumped the camera but thought it would have effected the whole shot not just the bright stars
- condensation, but this is the only shot effected shots either side dont have the same thing, shot within minutes of this one.
- the only conclusion I've made is that its some internal reflection in the lens/angle (from memory the lens would have been looking almost straight up) I had the lens caused the bright stars to streak.

Any one have any ideas?

Cheers

Matt

[killswitch]

You bumped it at the start of the exposure, likely when pressing the shutter.

The fainter stars take much longer to register/appear in the exposure, so only the brighter stars streaked. After the shake stabilized the fainter stars had the rest of the exposure to appear normally.

[iceman]

It's a pretty large bump if it was a bump!
And if the tripod wasn't secure and the camera dropped, I would also expect it to affect more stars.

[pmrid]

That hazy appearance suggests the clouds beat you. The streaks are too long to be explained by a simple bump. Must have been some kind of instability in your tripod.

Peter

[matt34]

Thanks for the idea Ed, potentially shutter bump but have the camera on 2 sec delay timer when not using the cable release, I think this was just a timer shot.

It was near a road and there were cars going past not sure if one went past while the shutter was open.



Its a pretty solid tripod, manfrotto 055 with a stable head. I think if it was a bump it should have blurred the rest of the image. at 100% I cant see any blur in the smaller stars (taken M8 (I think) as an example) or milky way dust clouds however at full zoom there are more effected than can be seen in the IIS version

[rogerg]

At some time during the exposure the camera has drifted steadily in one direction. The drift would have occurred reasonably quickly (over a short period of time - guess a few seconds) such that only bright stars have been recorded in the drift. The stars appear to trail slightly different directions only because of the lens distortion. I've seen this kind of thing quite a bit, usually it's because of some movement in the tripod or head (leg sunk, head tilted, quick release plate slipped).

The light patches could be from condensation, cloud, nearby lights, torch/head torch, etc. It's something like that :) Very small chance it could be light leaking in through the view finder if you had bright lights behind the camera.

[killswitch]

Only brightest stars will be captured the first couple of seconds of an exposure, thats when it was probably bumped or a tripod leg sank. The smaller stars are fine because they take a very long time to expose and the camera has stabilized by the time they are even exposed to visibility. Thin streaks suggest it was a quick movement during the exposure. This (http://farm9.staticflickr.com/8540/9005975760_9ac2e64dcb_c.jpg) might look sort of familiar

Either that or theres mini comets everywhere :eyepop:

[matt34]

Maybe there was some instability of the tripod initially that seems like a logical explanation and reminded me of an issue I came across on my NZ trip see attached its a lot less pronounced in the more recent shot so I didnt put 2 and 2 together. The attached was with the 24mm lens so less distortion on the corner shots but my tripod head ball joint has come loose.

What your saying Ed makes sense it most likely occurred early in the exposure meaning only the brightest parts where effected.

Thanks for the thoughts/suggestions everyone, off to ensure the ball joint is nice and tight again.

[matt34]

Yeah Peter I was flighting a loosing battle as the clouds came in quickly from the South West

[Octane]

Are you sure the lens wasn't fogged over or there wasn't high thin cloud?

I've had similar artifacts before but it was due to high thin cloud.

H

[matt34]

There was definitely high cloud rolling in, dont think it was fogged up lens as a shot taken about 25 seconds prior and about 45 seconds after dont have any sign of condensation.