Shooting star trails

shniks

Hi guys,


Below is a shot of a star trail I had done a few weeks ago. I am planning on heading out tonight to shoot some more star trails. The last time round, I had used one 20 minute exposure to get the trails. However there is some noise (and I think amp glow, although I am not sure- could just be the the faint glow from some citylights...). FYI I did not have LENR as I did not want to spend double the time per exposure (for the dark frame subtraction). Tonight I am thinking of shooting multiple exposures of between 30secs to a minute each and then stacking them. My question is that isn't there any way I can enable multiple exposure and then use the intervalometer in my D300 to record successive exposures on the same frame? That way I can avoid stacking the exposures later. The D300 is limits the number of multiple exposures to 10 per frame- so maybe I can take them at shutter speeds of say 2 minutes to 3 minutes. Then i could take an 11th exposure (single) with the lens cap on for the dark frame subtraction. Will that work? If so, should I shoot RAW or just go JPEG fine? My concern with RAW is that there might be too much delay between the time the shutter closes and reopens for the next shot.






Any thoughts on this? Is it feasible and if not, what is the downside?


Cheers,

HFMarshburnJR

Nikhil -

I use the MC 36 external intervalometer with my D3, and I shoot my star trails in raw with a 1 second delay between exposures and I have never had an issue. I have not tried to use the internal intervalometer (which I believe is the same as on the D300) in the fashion that you are describing, but it should work. Give it a try...what does it cost?

As for stacking, I use Image Stacker for this kind of photography. It is the best $20 I have ever spent. I have stacked up to 100 images into a single stack with this tool, and I have never seen the procss take more than 5 minutes. It is worth a look.

HFM

shniks

HFMarshburnJR wrote:

Nikhil -

I use the MC 36 external intervalometer with my D3, and I shoot my star trails in raw with a 1 second delay between exposures and I have never had an issue. I have not tried to use the internal intervalometer (which I believe is the same as on the D300) in the fashion that you are describing, but it should work. Give it a try...what does it cost?

As for stacking, I use Image Stacker for this kind of photography. It is the best $20 I have ever spent. I have stacked up to 100 images into a single stack with this tool, and I have never seen the procss take more than 5 minutes. It is worth a look.

HFM

Awesome Howard- really appreciate your input... My only concern about using the intervalometer was that the 1s delay would cause the star trails to be disjointed and not smooth.

HFMarshburnJR

shniks wrote:

Awesome Howard- really appreciate your input... My only concern about using the intervalometer was that the 1s delay would cause the star trails to be disjointed and not smooth.

Nikolai -

I am not going to say that it couldn't happen, but that has not been my experience. The only gaps that exist in the image I posted above were caused by the 30+ seconds between taking and evaluating my final (test shot before I set the intervalometer on auto pilot. My research has told me that there is only appreciable star movement after about 20 seconds at the aperatures I am shooting. Of course, your experience may vary.

HFM

shniks

HFMarshburnJR wrote:

Nikolai -

I am not going to say that it couldn't happen, but that has not been my experience. The only gaps that exist in the image I posted above were caused by the 30+ seconds between taking and evaluating my final (test shot before I set the intervalometer on auto pilot. My research has told me that there is only appreciable star movement after about 20 seconds at the aperatures I am shooting. Of course, your experience may vary.

HFM

That's a pretty good shot Howard. I am curious-is it a multiple exposure or were you just lucky that the North Star was just in tandem with the windmill (or structure- not sure what it is)...



Cheers,

HFMarshburnJR

shniks wrote:

That's a pretty good shot Howard. I am curious-is it a multiple exposure or were you just lucky that the North Star was just in tandem with the windmill (or structure- not sure what it is)...



Cheers,

Nikhil -

I actually planned the shot that way . I was able to locate Polaris and I set the tripod up such that it was blocked by the tip of the center spoke of the windmill. This is a stack of images that add up to an exposure time of approximately 1-1/2 hours. The windmill was light painted using a small flashlight with a tight beam from a position approximately 45 degrees to camera right. I painted during approximately 6 of the exposures.

That said, luck usually favors the prepared soul!!!

Thanks for the compliment.

HFM

shniks

HFMarshburnJR wrote:

Nikhil -

I actually planned the shot that way . I...
HFM

Woohoo... well done then....great eye to have seen that picture. I like it a lot..:D