Long Shutter Speed Interval Shooting?

[Brad Ede Photo]

Hi all I have a delema I was planing on shooting a star trail on my Pentax K1 mkii Full Frame with a Pentax 15-30mm Lens -

Camera Settings are as follows

Interval Composite - Interval is set to 2 seconds - Number of shots was 25 (but could be 80)

Start Interval with either timer or remote (I get the same result)

Composite Mode Average but doesnt matter if it is Average or Bright

Save Process is unchecked

Now my question is when shooting at anything longer than 0.8" I cannot capture the number of shots I have set i.e 25 it shoots one or two depending on the shutter speed before showing on the screen as "Interval Shooting Complete'.

Am I missing something in my settings or is it just a limitation of the camera?

Thanks in advance

Brad

 

[kypfer]

Yes, you're missing something

The interval time must include the exposure time PLUS the interim processing and saving time.

Try 30 second exposures with a 35 second interval, then if that's still too short either shorten the exposure time or extend the interval time 'till you get a satisfactory result.

Do note, saving RAW takes more time than JPG, as does any in-camera noise reduction induced by high ISO or long exposure and even possibly any processing overhead from the Astrophoto (NOT Astrotracer) in-camera setting. Depending on what you've got already, a faster card may also help with the write times.

Notes I've made for my own reference are as follows :-

Kiron 28mm f/2
Manual Mode - 30sec @ ISO 400 - wide open
~120 exposures - approx 1hr
Interval drive mode - interval 35 sec
Interval Composite "Bright" - Save Process

From memory, these were used either with my K-70 or KP ... higher ISO gave better exposure details but also introduced greater inter-exposure lag. It's all a bit of a compromise between detail and gaps in the trails ... the wider aperture lens the better. I've yet to try out my recently acquired Sigma 35mm f/1.4.

Do note, these are statements of facts from my experiences in my local environment, not recommendations for equipment or best practice.

Good luck.

 

[pvanni23]

You must count also the NR for long exposure if activated