endless-sky

Many people - and I am one of them - will tell you that for astrophotography a good mount is the most important thing. Everything rides on top of the mount and the best optics and camera would be useless if the mount wasn't able to handle the weight and track accurately. I would say HEQ5 Pro or similar is a good starting point. For astrophotography, you don't necessarily need a long focal length / big aperture telescope to get started. If you have any lens available for the Canon 600D, that would be a good starting point. In the future you can add a guide-scope and guide-camera to get longer exposures, but with short focal lenses (200-300mm or below) it's not really a starting necessity.

Then I would probably get this one: https://www.astroshop.eu/astromodified-dslrs/nikon-camera-dslr-d5600a/p,53133 Full range allows UV and IR to pass through, and that's not good for astrophotography: the lens will not focus all the light spectrum in the same focal plane and the further into the blue and red parts of the spectrum, the more this difference in focus will be noticed. If you cut those parts with a UV/IR cut filter, then you will not have problems reaching focus and the stars will not have a weird blue or purple halo around them. I would look in the used market, as well. I bought my D5300 used for 340 Euros and it only had 2000 shots taken (so basically new). The cost of astromodifying it in a shop, at least here in Italy, is around 200 Euros. So with 5-600 Euros you could have a fairly new, modified camera, instead of spending 1000+ for a completely new one.

I just checked the specs and compared it to the D5300. It looks like it is the exact same sensor, so the noise levels should be comparable to mine. If it is already modified (but with a UV/IR cut filter mounted, at least, not completely naked sensor), then I would buy it, if the price is good. Here is the link to the comparison: https://www.digicamdb.com/compare/nikon_d5600-vs-nikon_d5300/ EDIT: also, there are a lot of shops here in Italy that modify even Nikon cameras. I am sure you can find one where you live, too.

Hi, just like you, I started with a D90. Very old model, noisy, but that's what I had and I gave it a shot. After much researching and considering all the possible arguments between Canon vs Nikon, I decided to get still another Nikon: the D5300. The difference was night and day. Much, much less noisy, higher dynamic range, lighter. Beautiful images. I then astromodified it myself by removing the stock filter. I bought a 2" UV/IR cut filter and cut it to size, to prevent star bloating and I have been happy ever since. I would advice you to have it modified by a shop, though. Not much for the opening the camera and removing the stock filter, that was the easy part. The hard part was cutting the UV/IR filter to size, since I couldn't find any precut rectangular filters that would fit the original dimensions of the one I had to remove. Since you have a D90, I suppose you have already lenses that would fit a Nikon, so I would advice you to stick with Nikon. Most arguments pro Canon and against Nikon were about astrophotography software not supporting Nikon and similar. But with the newer Nikon models you have nothing to worry about. All the major, free astrophotography suites (AstroPhotography Tool, N.I.N.A., EKOS) work perfectly fine with my D5300. The D5500 could be another choice, but the sensor is exactly the same. The only differences are some added functions that are not really needed for astrophotography at all. Hope this helps!

Feel free to DM me, I don't mind helping if I can. I have gladly helped another guy with Astroberry. Whenever you need, I can point you to those threads, too, they have quite a lot of useful information and inputs from other users. Regarding plate-solving, yes, you can do it directly with the main scope and the ZWO camera that you will choose. You attach the camera to the telescope, slew the mount to an object, hit plate-solve and the software will do the rest for you. If you do it like this, the Starsense is completely unnecessary. Of course, it's not completely plug and play. You'll have to input some settings in EKOS for plate-solving to work (the dimensions of the sensor, pixel size and focal length of the telescope). You'll also have to download some map index files, if you want to do plate-solving offline (highly recommended and faster). But once you have done that and see your first plate-solving work, you'll never miss star alignment ever again. In fact, you don't need alignment at all - except for polar alignment, of course. The way I do it is like this: - polar align with the polar scope - slew to a bright star to focus (if the star is not in the field of view, plate-solve so that the mount can center it) - slew to the target that I want to image, plate-solve until the framing is exactly how I want it (also, I rotate the camera until framing is to my taste, at this point) - plan the sequence (number of exposures and exposure time) - enjoy the images as they are captured and shown on screen You only need two plate-solvings: one for the star that you are going to use for focusing and one for your target. The 3 / 5 star alignment is to get a better sky mapping, if you plan to do visual observation, but that's not really needed if you can go straight to the subject you are interested. If you want to image more than one target in the same session, then you can just slew to the next one and plate-solve again and repeat as necessary.

Save up on the Starsense and get the ZWO ASI 224MC, instead. The reason I suggest you to do this is because with the Astroberry package, you'll be able to do plate-solving and star alignment will be something that you'll never feel the need to do again. With plate-solving, all you have to do is take a picture of where the telescope is pointing (2-3 seconds is enough, just so that some stars are visible) and the software will calculate exactly where you are pointing at. From there, you can tell it to slew to an object, plate-solve again, and it will keep doing it until the object is within the specified tolerance away from the center of the frame (usually it takes 3-4 iterations). Save your money, let the software do the work for you!

Well, that's great to know! Right now I am not powering anything through the Pi, as everything has its own power supply (mount and DSLR, which is powered by a dummy battery). The only USB cables that go from the Pi to the mount and to the camera are for data transfer. So, it's good to know that if the only thing needing to draw power was the guide camera, the Pi would be good enough to handle it. Saves me from buying a powered hub, which I really don't have a need for, right now. Thanks for the input!

I just checked to make sure: if you register and log in, you can save all your favorite configurations for the FOV calculator!

Guiding is more of a necessity when longer exposure times are needed or when you use longer focal lengths (expecially when imaging DSOs, for planetary imaging is not much of a necessity). For example, I have been using a DSLR and a 300mm focal length lens for the past 6 months and the mount alone is good enough to track and give me round stars until 120s of exposure. But I am in the process of acquiring an 80mm f/6 refractor and even when reduced to f/4.8 (384mm focal length) I will definitely need guiding. Basically, you put a second small telescope or finder in parallel with your main imaging setup and you connect a camera (for example the ASI 120MM Mini or the 224MC discussed above) to it. The camera will loop a series of images (usually at 1 - 3s exposure) to a program (for example PHD2) made for the purpose of guiding. The program chooses a star in the field of view of the camera, calibrate the movements of your mount (AR and DEC), and then input corrections in AR and DEC to keep the chosen star centered in the cross-hairs. This way you can get much longer exposures without star trails. The ASI 224MC can definitely be used for guiding, also. These cameras all need power supplies of some sort, so I think you need a laptop or at least a powered USB hub. You also need a laptop to download the images, I don't think they have any internal memory. I personally use a Raspberry Pi 4 4GB to control my current equipment: a Sky-Watcher NEQ6 Pro mount and a Nikon D5300. Soon I'll add the ZWO ASI 224MC. There's a very nice pre-built suite, called Astroberry, that you can just install on an SD card, plug in into the Pi and you are basically ready to go. The suite comes with KStars (planetarium software to point the mount to the chosen objects) and EKOS (controller for all sort of devices: camera, guide camera, focuser, GPS, plate-solving, etc.) that also serves as planner for the imaging session.

I am glad you liked it! I also like all the customization that you can achieve using the filters and the options. And it's also nice that you can choose the objects based on a specified value of degrees over the horizon, for at least a certain amount of time. Another nice feature is the FOV calculator: you specify sensor dimensions and focal length and you see how big - or small - each object will look like on your photographs, for a given camera and lens/telescope combination.

I was undecided between the ZWO ASI 120MM Mini and the ASI 224MC as well. I wanted a camera that would be good for both guiding and planetary imaging. After some research, I decided to get the ASI 224MC. I read all sorts of problematic experiences with the 120MM Mini (others even with the 120MC-S), expecially under Linux/Raspberry (KStars and EKOS suite). Since I use a Raspberry to control my gear, I decided for the better camera. Even the dealer at the store where I ordered it from, without any negative input on my part, immediately suggested the 224MC for a more suitable camera, both for guiding and planetary imaging.

From my personal experience, I would start shooting only at astronomical darkness and when the object is at least 25° above the horizon (depending on the subject, of course, there might be objects that are never above 25°, but then are also limited by houses/trees). Here is a link to a good online planner: https://telescopius.com/ Enter your location and desired date and then click on "Targets" and "Deep Sky". It will tell you what will be available, when, and give you an altitude vs time curve for each object of interest. You can also filter the object list (object type, magnitude, size, etc.). I find it really useful!

Yes. Then I believe the box that needs to be checked is under the "Options..." (lower right of the screen) of the EKOS "Guide" tab, and it will be the first one ("Dither"). Then you need to specify how many pixels, how many frames to dither, etc. The box that you do not want to check, if dithering while guiding, is the one called "Non-Guide Dither Pulse". Hope this helps!

I use KStars as well! Are you using an auto-guiding setup? Because there are two settings for dithering, in EKOS: one for guided dithering and one for unguided dithering. Just make sure you select the correct one: I made the mistake of checking both of them, and the next time I tried opening EKOS it kept crashing. I had to manually edit the config file to remove one of the two settings (in my case, the guided dithering one, as I don't have a guiding camera, yet).

If you are undersampled, dithering certainly helps. It also helps with walking noise, so to me dithering is a win-win. If you use PixInsight for your pre and post-processing, you can process your dithered subs by checking "Generate drizzle data" in the StarAlignment process. This will create drizzle files, that then you will add to the regular ImageIntegration process: you integrate the image like you normally would, but click on "Add Drizzle Files" and check "Generate drizzle data" again, in the integration settings. Then, as a final step, you will use DrizzleIntegration process and select the drizzle files again and this will generate a final, drizzled image. Stars should appear a lot rounder in this image, with respect to the one that came out of the regular ImageIntegration.

Fantastic report! It's always nice when things go completely right, as they should, on some things like these. Unfortunately, spectacular comets like this one, and Hale-Bopp, the first one I have ever seen, feel too often like a "once in a lifetime opportunity", so when things DO go wrong, you feel like you missed out and inevitably wonder "will I ever get another chance?". I have a lot of beautiful - film - pictures of Hale-Bopp, and most of all, a great feel of wonder and magnificence etched in my memory, something that I am sure will stay with me throughout my lifetime, but not much to show regarding Neowise. I did wake up at 3 am a few days ago, when I finally had a clear morning, but things in the setup didn't quite work as planned and only manage to take a few shots between 4:15 and 4:30, when it was - sadly - starting to get too clear. So, I look at your - and other people's - experience with joy that everything worked out good, and - yes - even with a little bit of (friendly) envy.

Well, guiding certainly helps. For comparison, I have been using my NEQ6 Pro mount with the optics I currently have available: a 70-300mm lens (mostly at 300mm) and my Celestron C8 (both at native focal length and with a 0.63x reducer). I don't have an autoguiding setup, yet. But with the 300mm I have been able to take up to 2 minutes exposures without star trails, and that's all I need for a correct exposure, so I don't miss the autoguider, yet. But with the C8, even at 1280mm with the reducer, the highest exposure I can obtain is 30s (1/4 of 2 minutes), and that definitely is not long enough to expose much data. So, in this case, I do miss the autoguider. But, as I was saying, it also depends on the objects you are most interested in capturing, and for me it is the wide-field, beautiful nebulae. Galaxies and planetary nebulae can wait. So, 300mm is good enough. And the autoguider can wait. The comment about having a lot to learn was not meant personally to you. It was more of a general statement. I have been interested in Astronomy since my early childhood and the last time I did astrophotography was in 1997, when Hale-Bopp appeared. Back then I had a Celestar C8 and I was using a film camera, piggy backed on top of the C8, which I was using to guide, manually, with an illuminated reticule eye-piece. I considered that hard! I had to stay 10-15 minutes at a time, for every single photo, at the eye-piece, without touching anything, with a motor only in AR and the other hand on the micro-movement knob of DEC. I picked back up astrophotography in January of this year, after I saw some videos of what people are capable of capturing these days with a digital camera, some lenses, a good equatorial mount and digital post-processing. And with exposures lasting a mere 30 seconds or a couple of minutes, max! I was astonished and immediately hooked. Bought a used NEQ6 Pro and started imaging again with my Nikon D90 and a 70-300mm kit lens that I already had for terrestrial photography. I got to say it is probably harder now, than it was back then. At least, in the beginning. I had to deal with a GO-TO mount, software to control the mount, software to control the camera, all and every thing that can go wrong, with all these things communicating to each other. Learning to use the planetarium to slew the mount, learning to use the software to help me focus, plan the shot, learn plate solving, making all these things work. And then, learning to use the post-processing software, which accounts for 50% or more of the quality of the result. Learning all these things is hard, and with a very steep learning curve. But, man, when you get everything working, it's spectacular. You just sit at your laptop and watch the mount slew to the target. Take a test exposure with the Bahtinov mask, adjust focus till it's perfect. Plate solve and you know exactly where you are in the sky and how the object fits in your frame. Plan the sequence and start seeing the images getting downloaded to your screen. It's simply amazing and priceless and beautiful. I would never go back to how it was in the 90's. Not after I experienced all this. So, after all this rambling, the main thing I wanted to say was that with all those things to learn, adding an autoguider to the mix is just another layer of complexity, of things that can go wrong, of things to solve. So, that's why I suggested to start simple, which is mainly a reflection of what I have been doing. I have been imaging since January and I am now to a point that I feel comfortable enough with all the rest I mentioned to add an autoguider to the mix. I don't know if I would have been able to handle it from the start or how harder it would have made everything else. But with those short focal lengths, I really didn't need it right from the start, either.

More aperture is always nice, but for astrophotography you should really consider focal length, sensor size and the resulting field of view. What objects are you more interested in capturing? Also, shorter focal length is easier to guide, maybe for the HEQ5 the smaller telescope would be better suited. As for your other question, you'll eventually want both the coma corrector and the guiding setup. 650mm and 750mm are not going to give you very long exposure times, unguided. But without a coma corrector you most likely will not like the shape of the stars. I probably would get the coma corrector first, as you will have a lot of things on your plate to learn, solve, master. And add the autoguiding setup later, when you feel comfortable enough with the other steps of your setup. Good luck and clear skies!

I was going to suggest DeepSkyStacker, since AutoStakkert! is more for videos, but since you said it doesn't work on your computer... I really don't know what else you could use. Neowise should be well within the reach of your camera. It doesn't have H-alpha, so it shouldn't matter if your camera is modified or not. Same general tips as for the Milky Way: detach histogram from the left and keep exposure short enough to avoid star trails. Comets don't have the same apparent motion of stars, but for short exposure times it shouldn't matter if you are imaging from a still tripod.

Yes, the second option will give you better results for sure. 1/30th of a second is not enough to expose for the Milky Way. Generally, like happy-kat said, when shooting for deep sky astrophotography, you should try to get the histogram to move enough from the left side such that you are not clipping any data, but the exposure short enough that you don't get star trails. Experiment with the exposure time / ISO settings combination that gives you the best result in regard to these two ideal scenarios, and you should get a good starting point. Then it's all a matter of stacking images. The more, the better (up to a point of diminishing returns).

I think the reason it works on the Moon or the brighter and bigger planets (Jupiter, Saturn, Mars, Venus) is because these objects are already really bright and only require short exposures to show on the image. Shooting a video at 25 frames per second is equivalent to saying that each image is 1/25th of a second of exposure. If you tried that on Milky Way shots or DSOs, 1/25th of a second will not be high enough to record any data, I am afraid - maybe only the brightest stars would show, but nothing much in terms of dimmer nebulosity. With your setup, without an equatorial tracking device, you could still try to do some widefiled images of the Milky Way, maybe with a short lens (18mm or 35mm, for example) and set the exposure to 10-20s (experiment with the exposure length until is the longest one you can accept with little to no star trails) and then stack a lot of images. The video technique is more suitable for the Moon or the major planets. EDIT: also, I tried loading more than one video and it doesn't seem to work, so I guess you can only process and integrate one video at a time, unfortunately.

I don't think it would work if the Moon is not in the frame for the whole duration of the video, otherwise you would only get a partial result, equal to the smallest part that's in common with all the "single images". I think you should put the full disc of the Moon on the side of the framing and let the video run until just before the Moon goes out of the framing on the other side. I haven't tried doing more than one video at the same time, so I don't know if it works. I'll give it a try with a couple of videos tomorrow and then let you know if I could get it to work.

When AutoStakkert! analyses the video, it presents you with what it thinks it's the best frame. Then you place the grid, manually or automatically, select the number of pictures to stack (as a percentage or as a number chosen by you) and it then aligns and stacks the best frames (percentage or number, accordingly to what you chose).

Hi, the picture looks pretty good, maybe I would brighten it up just a touch. Another thing you could try doing, instead of taking still photographs, is record a video (if your camera has the function), this way you should be able to get 25-30 frames per second. Take a video of two / three minutes and then you will have a couple of thousands of frames to pick from and integrate. Then use AutoStakkert! to choose say the best 10-20% (will still be a few hundred images) and the results will definitely improve: more pictures, better SNR. You could even go for longer videos, to have more data to play with. The Moon - unlike for example Jupiter - doesn't rotate in such a short period of time, so you don't have to limit the length of the video to just a couple of minutes. Another benefit of the video is that the shutter won't keep opening and closing, creating unwanted vibrations that could ruin the single shot exposures.

Hi, in order to calculate the FOV of your imaging lens / camera combination, you do not need to enter the aperture. All the program (Cartes du Ciel, Stellarium, etc.) needs is focal length and sensor dimensions. Since in most cases the "real" focal length is not always exactly equal to the "nominal" focal length, to get the exact field of view you could also plate-solve an image of the night sky you took with that camera / lens combination (it doesn't need to be an extremely long exposure, a few seconds at high ISO is good enoug: the program just needs a few stars to be visible in the picture). This is an online solver that you could use: https://nova.astrometry.net/upload Choose the image file from the location of the PC where you saved it and click "Upload". Wait a few minutes and you will get the exact results of your camera / lens FOV. Then you can input that in the planetarium software you use and have a perfectly matched FOV to your camera / lens.