| Joined: | Mon Apr 2nd, 2012 |
| Location: | South Lakeland, UK |
| Posts: | 4066 |
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Personally I dont like the star trails as it makes the highlights distracting, which is why I asked about the single exposure shot.
My experience of this is with the Fuji. Shooting with the camera at ISO1600 for 20-40secs at f2.8
If you make a polar mount then be sure to document it well. I would attempt to make one here.
OK no problem, I accept the stare trails can be distracting, I just feel they add an unusual dimension to the image and have novelty value purely from a pictorial point of view. I have shown people both and they usually react with more interest and enthusiasm to the star trail images than the plain star image single exposure. I also feel they allow the range of colours to be more visible, rather than just white dots.
I have found you can extract a great deal more detail from each exposure but of course it also tends to increase noise perhaps internal camera noise and light pollution, it also seems to cause a lack of contrast due to the noise. More work needed... Maybe the NIK filters have a role here?
The single shot is a bit more demanding in a way because it needs to be as short as possible exposure to reduce the elongation of the stars on the periphery of the radius from Polaris. 30 seconds is way too long if it's to be used for a single image mid radius I guess it at least double the diameter to streak length. There are chart's and calculators out there which give the ideal combination of shutter speed/focal length/minimum aperture.
Yes, I will make lots of photo's of a polar mount. Changing tack slightly, I noted with interest in the D850 brochure some illustrations of the D850 mounted on a slide rig formed with a tripod and a large rock! I am trying to devise a slide rig to add linear motion to time lapse photography. Getting slow, smooth controllable linear motion is a bit of a challenge. I was interested to note that the rig in the D850 brochure appears to have wheels running on tube rails for the mount to slide along. I envisage adapting a cross cut saw slide mechanism with longer rails... The cost of this gear to buy 'the proper thing' is colossal. I'm sure it can be created from skip salvage bits and pieces. A car window winder motor would provide a simple motor which could be driven with a timer pulse feed to inch the head along the tracery slowly over some hours.
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Robert.