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12-27-2020, 12:14 AM   #16
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QuoteOriginally posted by Benz3ne Quote
Excellent info above. I’ve also seen some mechanical trackers that look pretty nifty - no batteries required!
Pentax does lead the charge somewhat for amateur astro with the O-GPS1 however, as above.
Mechanical trackers? Interesting.

12-27-2020, 02:38 AM - 1 Like   #17
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QuoteOriginally posted by Reciprocity Quote
Mechanical trackers? Interesting.
Omegon Star Tracker Mini, I think.
Looks like an interesting contraption and seemingly well regarded.
12-28-2020, 12:43 AM - 1 Like   #18
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QuoteOriginally posted by Benz3ne Quote
Omegon Star Tracker Mini, I think.
Looks like an interesting contraption and seemingly well regarded.
Right! ...and now finding a place without light pollution.
12-28-2020, 09:46 AM - 1 Like   #19
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Notes on "star trackers":

When using the Pentax astrotracer functions, there are some limitations. Wide angle lenses will show some blurring of star images towards the outer field because the motion correction is being done on a flat plane in the camera by moving the sensor. This motion isn't correct for all of the stars in the field so the further the stars are from center field, the worse tracking will be. There are limitations on the time tracking can be done this way because the sensor can only move so much.

Using a tracking mount overcomes all the aforementioned issues because the entire camera is being moved in a circular fashion to track stars and sky objects. Widefield lenses can be used and will be sharp to the edges (within the lens IQ limits). Exposures can be much longer and are only limited by camera, batteries, mount calibration, weather, and how long it's dark. The downside of a tracking mount is its cost and the calibration it needs when setting it up. Of course, it also takes up additional space beyond that of just a camera and regular tripod. It also needs a good tripod so it can be extra vibration free and steady with the load. Tracking mounts are limited in what they can accommodate load-wise, but more $$ can get mounts with greater load capacity, right on up to world class telescope size

The choice depends a lot on what kind of sky shooting you want to do. After all, you can get some pretty neat looking pictures with no guiding - just long exposures and the right setting (star trails).

12-28-2020, 09:57 AM - 1 Like   #20
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QuoteOriginally posted by Reciprocity Quote
Mechanical trackers? Interesting.
Barn door trackers. Several users on this site have made them in the past.


Steve
12-28-2020, 08:40 PM   #21
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QuoteOriginally posted by Bob 256 Quote
Notes on "star trackers":

When using the Pentax astrotracer functions, there are some limitations. Wide angle lenses will show some blurring of star images towards the outer field because the motion correction is being done on a flat plane in the camera by moving the sensor. This motion isn't correct for all of the stars in the field so the further the stars are from center field, the worse tracking will be. There are limitations on the time tracking can be done this way because the sensor can only move so much.

Using a tracking mount overcomes all the aforementioned issues because the entire camera is being moved in a circular fashion to track stars and sky objects. Widefield lenses can be used and will be sharp to the edges (within the lens IQ limits). Exposures can be much longer and are only limited by camera, batteries, mount calibration, weather, and how long it's dark. The downside of a tracking mount is its cost and the calibration it needs when setting it up. Of course, it also takes up additional space beyond that of just a camera and regular tripod. It also needs a good tripod so it can be extra vibration free and steady with the load. Tracking mounts are limited in what they can accommodate load-wise, but more $$ can get mounts with greater load capacity, right on up to world class telescope size

The choice depends a lot on what kind of sky shooting you want to do. After all, you can get some pretty neat looking pictures with no guiding - just long exposures and the right setting (star trails).
Ok, I understand. I've read in the above mentioned information that with a certain exposure time (with analog film) you could have a reasonable result as well.
12-29-2020, 09:19 AM   #22
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QuoteOriginally posted by Reciprocity Quote
Ok, I understand. I've read in the above mentioned information that with a certain exposure time (with analog film) you could have a reasonable result as well.
Reasonable for sure - it was done for many, many years by observatories and non-professionals alike. It's just entails a lot more effort and has some disadvantages digital sensors minimize or do away with.

Film has one advantage and that is in large telescopes, large photographic plates can be had whereas sensors to cover images that size are harder to realize (think of observatory telescopes as really large lenses with pretty large images). I don't think that's an issue for most of us with camera lenses and smaller telescopes. Film, though, is really fun to experiment with and you should be able to get better than "reasonable" results with a little effort. Good shooting

12-29-2020, 11:57 PM   #23
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QuoteOriginally posted by Bob 256 Quote
Reasonable for sure - it was done for many, many years by observatories and non-professionals alike. It's just entails a lot more effort and has some disadvantages digital sensors minimize or do away with.

Film has one advantage and that is in large telescopes, large photographic plates can be had whereas sensors to cover images that size are harder to realize (think of observatory telescopes as really large lenses with pretty large images). I don't think that's an issue for most of us with camera lenses and smaller telescopes. Film, though, is really fun to experiment with and you should be able to get better than "reasonable" results with a little effort. Good shooting
Thank you very much Bob!
12-30-2020, 02:35 AM - 2 Likes   #24
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My minimal equipment is a Pentax K50 (not modified), a skywatcher star adventurer and a rollei c5i tripod.

The picture of the orion nebula M42 was taken with a 10$ ebay auto-revuenon 300mm f5.6, 45x140 seconds iso 200. Stacked in SiriL with flats and bias. Moon was about 65% this night, so there aren't much details.
Theres a 6kg weight in the bag because normal photo tripods aren't very good for astro photography. The lense warmer was a 20$ amazon buy and is doing it's job pretty well.

This setup is far from perfect and i need some rails to balance lense and camera a little better. if you want to go deeper into astrophotography you nood some better equipment. Most important is the mount.

---------- Post added 12-30-20 at 03:28 AM ----------

QuoteOriginally posted by CharlySchramm Quote
My minimal equipment is a Pentax K50 (not modified), a skywatcher star adventurer and a rollei c5i tripod.

The picture of the orion nebula M42 was taken with a 10$ ebay auto-revuenon 300mm f5.6, 45x140 seconds iso 200. Stacked in SiriL with flats and bias. Moon was about 65% this night, so there aren't much details.
Theres a 6kg weight in the bag because normal photo tripods aren't very good for astro photography. The lense warmer was a 20$ amazon buy and is doing it's job pretty well.

This setup is far from perfect and i need some rails to balance lense and camera a little better. if you want to go deeper into astrophotography you nood some better equipment. Most important is the mount.
I forgot something... you will need an intervalometer. Bought im from amazon too. I'm using the one from hahnel for about 80 bugs... there are some cheaper ones too.
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12-30-2020, 10:55 PM   #25
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QuoteOriginally posted by CharlySchramm Quote
My minimal equipment is a Pentax K50 (not modified), a skywatcher star adventurer and a rollei c5i tripod.

The picture of the orion nebula M42 was taken with a 10$ ebay auto-revuenon 300mm f5.6, 45x140 seconds iso 200. Stacked in SiriL with flats and bias. Moon was about 65% this night, so there aren't much details.
Theres a 6kg weight in the bag because normal photo tripods aren't very good for astro photography. The lense warmer was a 20$ amazon buy and is doing it's job pretty well.

This setup is far from perfect and i need some rails to balance lense and camera a little better. if you want to go deeper into astrophotography you nood some better equipment. Most important is the mount.

---------- Post added 12-30-20 at 03:28 AM ----------


I forgot something... you will need an intervalometer. Bought im from amazon too. I'm using the one from hahnel for about 80 bugs... there are some cheaper ones too.
Very nice picture, thank you again for all the information. And a happy new year as well!
12-31-2020, 04:09 PM - 1 Like   #26
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QuoteOriginally posted by CharlySchramm Quote
The picture of the orion nebula M42 was taken with a 10$ ebay auto-revuenon 300mm f5.6, 45x140 seconds iso 200.
At 90+ minutes of exposure there is still likely a lot more in the details that can be pulled out of that shot unless you are in a very light polluted area.
12-31-2020, 08:32 PM - 1 Like   #27
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QuoteOriginally posted by CharlySchramm Quote
The lense warmer was a 20$ amazon buy and is doing it's job pretty well.
Welcome to the Pentax Forums! That is a nice setup and a great photo. Do you happen to have a link or product name for the lens warmer?


Steve
01-01-2021, 11:15 AM   #28
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QuoteOriginally posted by stevebrot Quote
Welcome to the Pentax Forums! That is a nice setup and a great photo. Do you happen to have a link or product name for the lens warmer?


Steve
It’s the COOWOO lens warmer. It has the „Amazon Choice“ label.

---------- Post added 01-01-21 at 11:18 AM ----------

QuoteOriginally posted by MossyRocks Quote
At 90+ minutes of exposure there is still likely a lot more in the details that can be pulled out of that shot unless you are in a very light polluted area.
The moon was about 68% this night and it was close to Orion. Guess that’s why there are details missing.
01-01-2021, 12:06 PM   #29
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May I suggest you take a look at weatherspark.com or some such site to see the annual cloud cover at your intended location.
This is one reason I don't get out to do much astro, combine this with opportunity and moon position / phase and the number of chances can reduce drastically.
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