hello all. Still new to night photography, this is really only my second attempt. There was a good ISS pass this morning, beginning 1 hr before local sunrise, coming in from the NNW and peaking at 68 degrees, so a good chance to get a long streak. I had previously tried an Interval Composite, with no success, so decided to try a conventional interval and stack the results in PS. Something else i am new to. From my one previous experience, I knew the camera would do 25 sec exposures at 5 sec intervals, so i just assumed it would do 30 sec exposures at 2 second ( the minimum) interval. Carefully set up, did a couple of test exposures @ 30 secs just before the pass, settled on Is-SO 800 and F5.6. I started the sequence just as it came into view, it did 2 exposures then got a message of Interval Sequence Complete. WT? Quickly started again, same result, and again, to cover the pass. So it is a bit gappy.
When I layered the six exposures the result was as below, after doing some corrections in LR first, and syncing al the changes..
Obviously over-exposed, I should have made the adjustments on the last shot, and synced backwards. So I tried this but not much change. But what is the odd effect around the larger stars, lower in thee more exposed art of the finished composition? They look like dimples-- part of the layering? The layering hasn't worked for the stars, giving that stuttering look. After some adjustment.
Still not good, the only way I could be rid of it was to darken it overall, as below.
So now the stars simply look like I have had camera shake.
The last shot is one of the interval pictures.
So my next attempt in two days time will be a Bulb shot. At least I will have star tracks rather than stutter. My IR remote has chosen a bad time to fail so I will be using the Ricoh Image Capture app on my phone to trigger Bulb. After 30 secs @ F5.6 and ISO 800 gave me a fairly good exposure, and this pass will be across the western sky at the same time, I will be trying 420secs at F.8 and ISO 200. Do my maths add up?