What went wrong

[Leo.G (Leo)]

https://i.postimg.cc/Zn4Y1k6T/Birthd...-5903x3942.jpg


20 frames, 16 seconds f2,8 - Nikon D810, Rokinon 14mm f2.8-ED.
50 dark frames, no vignetting frames

Manfrotto tripod, intervalometer, mirror locked up to prevent shutter shock.


The issue (unless I went to warp one without knowing it) is I usually use 30 -35 second exposures with the same set up and do not get the streaks clearly visible in the outer areas of the image. It was also a rare, windless night so it's not a breeze shaking the set-up.
It was below 0c and I had a warming ring on the lens to stop it icing up, a set-up I've used many times.


I'm guessing somehow I've shifted the focus just slightly at some point in the set up, just off the focal point.

My lens has been tested and clearly marked for best focal point at infinity for the night sky (tens of hours and too many shots to count).

I'm hating that green hue from the new LED street lighting!


Oh, this streaking is in the individual raw frames so it's not a stacking issue (for which I used and love Sequator)


Thanks!

[JA]

Hi Leo,

Just also check- In Sequator are you sure you set /masked the stationary foreground correctly? The blurred house chimney/antenna area suggests you may not have set the foreground correctly. Try it again just in case. From memory there is also a wide / tele setting for some function/s (I don't recall which, possibly light pollution??)

Best
JA

[Leo.G (Leo)]

Thanks JA, I did check the settings in Sequator but the streaking is also in the raw images untouched. That's why I'm thinking it may be a focus problem.
An admission, my heater band fell down the lens and I slid it back into place in the dark (not shooting at the time) and I think I could have thrown the focus off by just a small amount.
I do know I get minimal drift at 30 seconds so at 16 there should have been absolutely none. Otherwise the focus doesn't look that bad to my bad eyes.

Hmm, I didn't even look at the antenna, maybe I had the smallest amount of shake on the tripod. I haven't noticed any shake with it previously and I don't touch any of the equipment while it's shooting, I walk away and have a smoke or a coffee usually.
In saying that I may have not secured the tilt locking on the tripod so it could have possibly crept down the smallest amount during shooting. Because of the position of the night sky (the earth) I was shooting at an alignment point I've not done before and had to have the tilt lock knob out in front of the camera to get the near vertical angle rather than how I usually set up. I may not have tightened it securely, not wanting to bump my alignment.

It was my sons birthday, I'd had a very long 2 days ( I make him a 3 sponge black forest cake which is hard when room temperature eggs are required for good sponge cakes and my kitchen temperature mid August is usually lower than my refrigerator temperature-That's where a rack mount server vent holes and a couple of steamer pots bolted back to back come in VERY handy) and didn't even get out to shoot a birthday sky image till 1:30AM, after his actual birthday.

It's just a silly thing I do most years, weather permitting.