You don't need a telescope

Scrumhalf wrote in post #18450366
Pagman, I would recommend breaking this learning process into two pieces.

You've got hardware, and you've got post processing, both of which can pose challenges for the beginner. I would put the hardware off for now and focus just on the processing.

First, put a wide angle lens on your camera so that you don't need a tracking mount. You can take relatively long shots without getting star trails if you have a wide angle lens. Take several such shots, take darks, etc. and then learn how to stack shots, deal with noise and light pollution, etc. The advantages of doing this is that a) you don't have to muck around with expensive mounts, learning how to polar align, etc. and just stick with your tripod, and b) you don't really need to find your way around the sky, which can be a learning process in itself, unless you are an experienced visual stargazer, in which case this does not apply to you. All you've got to do is to find a relatively dark place, point the camera at a relatively rich part of the sky and shoot away.

Once you've figured out how to do the processing and are getting good at taking shots of star fields, then you can focus on getting a better mount so that you can take shots of deep sky objects with your 300mm. You also would need to get reasonably good at finding things in the sky (or you can get a go-to mount, in which case you basically punch in the name or Messier/NGC number of your object and the mount does the finding for you).

Hiya sam, thanks for explaining all the above, to be honest I'm not in a position to buy anything at the moment, I am interested to know how I can make the most out of what I have -
My Nikon D7100 is fine as its good with noise and very adjustable.
My Nikkor 300 f4 IF ED is one of the sharp 300mm lenses, but I am focal limited to just that.

I havn't done bad with Jupiter and his moons, but I was hoping to get more color from constelations etc.

Here is one of my Jupiter shots with my gear.

P.

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I really like these. Good work.

Pagman wrote in post #18449299
Is there an easy way to get better detail like those above but without needing a tracker, I have decent gear D7100 with my 300 f4 so the equipment is probably upto the job, my tripod is just about ok, but how can I get several exposures plus darks if I do not use a tracker?

Any ideas how to get near to this without tracking equipment etc?


P.

You can certainly try with very bright DSO targets like the Andromeda Galaxy or Orion Nebula, short exposures (say ~0.25-0.5 second) at an ISO of 1600 might yield enough signal with the f4 aperture, you will need to stack A LOT of exposures (think: 100+ if not more) and you'll only be getting the core of those objects. Try it and see, try to not overdo the processing, just focus on getting good detail in the core of those objects.

pdxbenedetti wrote in post #18477181
You can certainly try with very bright DSO targets like the Andromeda Galaxy or Orion Nebula, short exposures (say ~0.25-0.5 second) at an ISO of 1600 might yield enough signal with the f4 aperture, you will need to stack A LOT of exposures (think: 100+ if not more) and you'll only be getting the core of those objects. Try it and see, try to not overdo the processing, just focus on getting good detail in the core of those objects.

Would the same thing follow for photographing Pleiades?

P.

Pagman wrote in post #18477186
Would the same thing follow for photographing Pleiades?

P.

What he said..... The amount of color you can get in any DSO will depend a great deal on how much light pollution you have to contend with. Recently, I stacked 62 images of the Andromeda Galaxy, and managed to get the brighter central area, but without much color. But the Orion Nebula is brighter and the colors are more pronounced, so I managed to get a bit of color in the picture I took of it in a single exposure at 600mm, 10 Seconds, f:6.3, and ISO 800. By increasing the ISO to 1600, and the aperture to f:4.0, you should be able to shorten the exposure if you notice star trails, or just get more light and color on the sensor if star trails aren't much of a problem, and your atmosphere allows. It costs you nothing but some time to experiment with different exposures and subjects. Just set up and start experimenting to see what you can do.

Here are two versions of the Orion Nebula I took - one just as it came from the camera (but reduced) and the other after I adjusted the color, gamma, and contrast to bring out the colors. These are single exposures, but I took 101 exposures and stacked them. I'll add another post to show you what stacking did for the image. It improved the image, but the really faint colors still won't overcome the light pollution.

I tried and tried to get the blue filaments around the Pleiades, without any luck. I need a darker site to get anything that faint.

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Pagman wrote in post #18477186
Would the same thing follow for photographing Pleiades?

P.

Pagman, this is the result of stacking 101 images like the one I posted a couple of minutes ago. I had the camera on my Orion tracker, but if you're careful to realign it after every 4 or 5 shots, you should be able to stack some images, too... it'll just be a more tedious procedure. And a lens with a shorter focal length would decrease the need to be so meticulous. I've used my kit lenses for a lot of the things I've photographed, with fairly good results. The best image I've produced of the Andromeda Galaxy, so far, was with my 55-200mm kit lens.

Again, this is a stack of 101 images - 600mm, 10 Seconds, f:6.3, ISO 800, WB = Daylight

The colorful ones I posted are in .bmp format. As you know, .jpg compresses the image, and loses some information during the compression. The first data that's lost is the color saturation! But the .bmp files are over 4 times the size of the .jpg files.

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While I'm here....

Quite a while ago, I tried to take some astro-photos with my 50 year-old, 50mm, f:1.4 lens that came with my Nikon FTn camera, without much luck. The coma, CR, and other distortions were pretty bad. But the other day, I decided to try it again, but stopped down, this time. At f:2.8, it amazed me how sharp it was. I think it's as sharp as any lens I have, and better than a lot of them.

This is the Orion constellation, full-frame in the first one, and cropped to show only the belt in the second.

This is also the third time I've loaded them... In the first two attempts, posting them caused them to lose almost all the color, and in the originals, the stars were very colorful. Why does posting them wipe out all the color? I went back and increased the saturation a LOT for this attempt, but they still lost a lot of color.

(POTN doesn't even list any prime lenses for Nikon, much less the old one that I used. So I selected a zoom lens I own to have the postings listed in my gallery.)

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Roy A. Rust wrote in post #18478170
(POTN doesn't even list any prime lenses for Nikon, much less the old one that I used. So I selected a zoom lens I own to have the postings listed in my gallery.)

Roy,

Go to AMASS Forum Software Talk then create a thread asking Pekka to put into AMASS! the lenses you have found that are not included.

Those are amazing shots roy great detail and love that color, how can you do multiple shots for stacking without a tracker, I assume each shot needs to be the same for stacking? just think it would be a difficult task to keep moving the camera on a tripod for 100 or so shots of the same galaxy etc.

P.

Pagman wrote in post #18478264
Those are amazing shots roy great detail and love that color, how can you do multiple shots for stacking without a tracker, I assume each shot needs to be the same for stacking? just think it would be a difficult task to keep moving the camera on a tripod for 100 or so shots of the same galaxy etc.

P.

Thanks...

Since you asked..... The individual shots don't have to be perfectly aligned to stack. The first thing Deep Sky Stacker does is register the stars in the frame to locate their positions. Then when stacking them, it shifts and rotates each image to align the stars in each shot with the reference light frame it creates. And you don't need to stack very many at first. Just try stacking a few at a time, until you learn a bit more about the program and what it will do before trying to stack a lot of images. Stacking 10 or 15 shots will make a lot of difference in the image. I've stacked as few as 4 shots and liked the results (from a dark site).

With the short exposures you will be limited to without creating star trails, you should be able to get 4 or 5 shots of an object before you have to reposition the camera a tiny bit for the next few shots. Pick out a point in the image to center the shot, and each time you shift the camera, re-center the object to start another series of shots. Deep Sky Stacker will align all the shots, and produce a composite. Then you have to learn a lot about post-processing the image that Deep Sky Stacker comes up with. Usually, mine are nothing but a blank, bright screen, and I have to adjust the histogram peak on the curve to bring out any image. It'll take a lot of trial and error to figure out how to adjust it so it suits you. There will be a lot of different edges apparent around the edges where the individual frames don't overlap. Just crop the edges to get the final image that contains the stars from all the shots.

The only way to figure it out, is to experiment with it. Give it a try with a few shots at first, and then add more as you get the hang of it. Good luck! Oh, you should start out with a wider-angle lens and get comfortable with it before attempting it with your long lens. Hope this helped, and isn't too confusing.

This captured image from Deep Sky Stacker shows how misaligned images can be stacked.

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Thank you so much for all that ron, I am gagging to get out with clear skies and have a go, I did some research on the subject and understand a good starting point to avoid star trails with my 300mm on my crop frame, is no more than 2sec exposures, do I need to do some darks frames also, would a good sequence be - 1600Iso, f4, 2sec - 10 frames then put the lens cover on and another 10 frames, then opened in Deep sky stacker?

P.

Pagman wrote in post #18479037
Thank you so much for all that Roy, I am gagging to get out with clear skies and have a go, I did some research on the subject and understand a good starting point to avoid star trails with my 300mm on my crop frame, is no more than 2sec exposures, do I need to do some darks frames also, would a good sequence be - 1600Iso, f4, 2sec - 10 frames then put the lens cover on and another 10 frames, then opened in Deep sky stacker?

P.

Fixed it for you P.

Inspeqtor wrote in post #18479055
Fixed it for you P.

Thank you charles and appologies roy

P.

First attempt at shooting the Orion nebula! Not as good as some of the other shots on here but I'm happy with it.

16x1 second frames unguided at ISO 12800.
Cropped from 200mm @ f/2.8 on a 6D


Also I know it's kind of a weird crop, as it's kind of just there on the right, but I liked how it looked so I left it.

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Pagman wrote in post #18479037
Thank you so much for all that ron, I am gagging to get out with clear skies and have a go, I did some research on the subject and understand a good starting point to avoid star trails with my 300mm on my crop frame, is no more than 2sec exposures, do I need to do some darks frames also, would a good sequence be - 1600Iso, f4, 2sec - 10 frames then put the lens cover on and another 10 frames, then opened in Deep sky stacker?

P.

Pagman... I don't know how long an exposure you can get with a 300mm lens without star trails, but I went out tonight to take some with my newly-discovered OLD 50mm, f:1.4 lens. I just had the camera mounted on a standard tripod, and didn't realign it at all during the 16 and 10 minutes it took to take over a hundred shots for each of these images. I still think you should start with a shorter focal length lens to learn how stacking works. But, whatever floats your boat is fine - might be a bit more frustrating to start with the 300mm though.

I used a remote trigger to take these so I wouldn't shake the camera. 104 shots of the Andromeda and Triangulum Galaxies, taken at 6 seconds each, f:2.8, ISO 3200, with a Red Intensifier Filter to reduce the effects of light pollution. The image of the Pleiades is from stacking 101 shots, at 4 seconds each, f:2.8, ISO 3200, with the filter. The dark margins on these are due to the shifting Deep Sky Stacker has to do to align the images. I didn't crop them, to show you how DSS shifts the images for alignment.

(And again, posting them significantly reduced the amount of color saturation that each image had in it.)

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