Charming Potato

Thank you for sharing your insight. Unfortunately, at this time I do not have the money to spend on this hobby. I guess I will stick to the easier targets for now and keep learning with what I have. Thank you!

Hello. Jupiter is visible at a favorable spot at night these days. I was wondering if it is possible to image it with a kit lens 50-250 @250mm F6.4 with a DSLR crop sensor (Nikon Z50, APS-C)? If so, what is the optimal way of doing so? Imaging? Video frames?

Is it required to take calibration frames for it for it? Specially flats since I have some smudges on my camera sensor and lens. What program is used for it? From what I have seen, all the images are taken as videos using a dedicated astro camera and some sort of scope. I found the following images where it was still shots stacked somehow?

I do have SA GTi mount.

Finally, after weeks of waiting, we had clear skies the other night and I was finally able to get out for imaging! Here's my first attempt at M31 from my backyard.

• Nikon Z50.
• 50-250mm kit lens at 135mm.
• 100 lights @90secs, 50 dark/bias/flat frames each.
• Star Adventurer GTi.
• Siril for stacking and processing.

I started the imaging session right as the sun set, so by the time I set up and finished polar alignment and connected everything, it was already dark. The first 15-20 shots were a bit bright for some reason, I don't know why that was the case (I started shooting 1 hour after sunset), but Siril took care of it in stacking compared to DSS which had a worse sort of result. I took 15 darks right after that since the temperature was going to drop by about 4-5 degrees Celsius, so I took these around the beginning of the session, and the rest at the end of the session. Was that a good thing to do or did I waste my time?

Also is there a way to go past 90-150 seconds of exposure with SA GTi, or do I definitely need a guide scope for that? I think my polar alignment was quite spot on, but when I was going through the pictures, I did notice that the center of the image has moved quite a bit in some of them. Which I'm guessing is tracking errors?

Thank you everyone! I had another go at the same target on a different night, but this time I went with 37x120 seconds exposures at 100mm F5 rather than 150mm. I used Siril to process the image this time and I am much happier with the result. I used Starnet to remove the background and for stars reduction, and it was much better! I did learn that this is not a very good target for unmodified camera in a light polluted area, so I'll try a different target next time, but overall I'm very happy with Siril.

Here is the stacked image of this new attempt: https://drive.google.com/file/d/1Veox_W6nJ9VU_MEnmZozeIl2Avygm5YG/view?usp=sharing

If someone can process it their way, I would like to see how my attempt compares to experts here so I can understand what I am missing.

I finally got the chance to test my mount. Unfortunately, I couldn't connect to my RPi because it wasn't connected to the WiFi and I didn't want to configure it to run its own hotspot again, so I decided to just go with the mount's (SA GTi) tracking. After polar alignment, I issued the goto for NGC7000, which seemed a little bit out of focus because I had the lens at 250mm. Ended up using 155mm, which was my first mistake; I believe it zoomed in WAY too much. Then halfway through clouds came so lost about 10 frames, and then lost about 30 frames because dew started forming on the lens and I didn't notice it and that was my second mistake.

Nikon Z50

Star Adventurer GTi

Nikon kit lens 50-250mm @ 5.3

132 x 30sec (including the frames blurred by dew)

39 flats, 20 dark, 92 bias frames

I'm also bad at post processing, so any help would be really appreciated as this is just my second picture (first with a tracker). This was shot from a Bortle 8 area.

26 minutes ago, Elp said:

1. Yes tighten the clutches, they don't need to be rock solid tight, just hand tight.

2. Home position is correct, when you're outside the front of the mount will be pointing to true north/Polaris, once polar aligned the camera will be centred on Polaris.

3. Wedge adjusted to your latitude, on some separate EQ wedges I've used their latitude scale has been backward (illogical so they were 90-latitude). You'll know when you're outside, looking down the side up at polaris you'll either be near or far.

4. Set up your counterweights as per Ra and Dec balancing. They may be on about so the weights do not hit your mount or tripod.

5. You can try the goto indoors if you point it to true north and have the altitude set correct, issue a goto and cross reference it's rough position to a star atlas like stellarium, just make sure the date time, daylight savings time, UTC time offset and location are correct (all these relate more to a traditional hand controller), I'm guessing it'll read your settings off your phone or something if you're using a phone app (not sure how you control it on a SAGTI).

Thank you so much! I will try adjusting to north inside see if goto is working as intended.

EDIT: I pointed it roughly towards true north, and now goto seems to be going in the right direction! I can't wait to try it out once this thunderstorm goes away! Thank you @Elp and everyone else here for all the help, I really appreciate it!

2 hours ago, Elp said:

The counterweight is to balance the RA. Typically you balance the RA first so it doesn't move when you have the RA axis loose and rotate your setup around the RA and let go. Once that's done you return the RA to home position (imaging load pointing front on top of mount in line with mount with counterweight shaft pointing perpendicular at the ground (with altitude angle)), tighten the RA clutch then loosen the Dec clutch and see how that moves. You usually need a longer dovetail bar to be able to move the imaging load forward or back to balance in Dec. If your load is wide you have to counterweight balance your equipment (as an example camera to one side, guidescope to the other) so when you rotate around the declination and the clutches as loose the load shouldn't move. Once done return back to home position and tighten declination clutch. You can check the Ra again but it's normally fine.

Congrats on the purchase.

Thank you! That helped and it seems to be balanced on both axis now! Luckily I got my portable power station as well today (Talentcell 72W 100WH as you suggested), so I was able to connect to test if everything works and it seems good to go! I tried going towards a target just to test, but the goto was WAY off of it, and I believe that is because I didn't polar align it yet? It's day time, and unfortunately there seems to be cloudy skies throughout the week, so won't be able to do anything this week, but just wanted to test.

Two things I wanted to confirm as I couldn't find them in the manual:

1. Do I need to tighten the RA/Dec clutches after they're balanced? Like tightened to the point where I cannot manually move them and let the motors do the work?

2. Attached picture is what I believe should be the "home" position of the mount. Is this correct?

EDIT: One more thing, let's say my latitude is 65.123123, that means I need to skew the polar wedge to 65 on the polar scale, right? If that is the case, is this considered a low or high altitude? Because it says to equip the counter weights in a different position if your latitude is low. I tried finding it out but couldn't understand it.

So I got my SA GTi today (yay). Now I tried assembling the mount with everything attached, and I am having trouble balancing it in DEC axis. In RA it is okay, but when I tilt the camera 90 degrees on the DEC, it becomes weight side heavy. I have tried making the weight go as far up as possible, but it doesn't have the capacity to go above 70% as then it starts to hit the polar alignment dial and the body of the mount.

I believe it might be the attachment I have for the camera to connect to the mount. I got this quick release plate: https://www.teleskop-express.de/shop/product_info.php/language/en/info/p9348 . It doesn't perfectly sit in the mount's mouth (?) and I think this might be the reason why I cannot get it to balance in the DEC axis? It is also too low so the camera body hits the tightening screw that holds the plate onto the mount, so I have to put the camera not parallel to the plate.

Maybe I am doing something else wrong?

EDIT: I read @Elp's comment after I had ordered everything, so I'm more and more certain it is the attachment that is holding the camera. If that is the case, is this a good dovtail plate? https://www.teleskop-express.de/shop/product_info.php/info/p237_TS-Optics-Dovetail-Mounting-Bar-Vixen-style---100-mm-slotted-hole-and-1-4--screw.html

2 minutes ago, iapa said:

PHD2 will send guide control via the usb port on the mount

Oh, I'm dumb. It was right in front of me and for some reason my brain decided to ignore it. Thank you so much! I think I will go ahead with this setup.

12 minutes ago, iapa said:

Pg 54 of manual says it is a high speed USB port.

Apparently Snapbridge can be used for shutter control: https://www.dpreview.com/forums/thread/4631473

 

That's perfect, thank you.

9 minutes ago, iapa said:

The mount is controlled via the USB port

Yo do not need the use the ST4 port for guiding. I believe AstroBerry support PHD2 for guiding.

So that means it can be done without the cable? Over WiFi I believe?

18 minutes ago, iapa said:

On pg4 of the user manual it states:

Fits standard 3/8 and 1/4 inch tripod/quick release brackets

 

I don't see that in the manual on page 4: https://inter-static.skywatcher.com/downloads/sagti_manual_rev8c.pdf

I believe my question wasn't clear. What I wanted to ask was that do I need a special plate/equipment to mount my camera to the head of the mount?

6 minutes ago, iapa said:

I see it has a USB port. 

With my Nikon D90 I used an application called BackYard Nikon, it’s windows only, but if the USB is there it may be possible - I don’t know Astroberry at all I’m sorry.

I'm not sure if it transmits data over that port. I've tried looking into the manual but can't find any info. Searching through internet I couldn't find anyone who uses it with a cable. I guess I'll just have to figure out a way to connect it somehow through Bluetooth or Wifi.

Thank you everyone for the great suggestions. At this point, I'm thinking I will go with the SA GTi. The kit comes with a tripod and pier extension. And I feel like this is a very good investment that will last me a while, and it is much easier to operate (from watching the YouTube videos at least) and offers a lot of features out of the box. There are a few things that I wanted to clarify if possible:

1. I use Nikon Z50, and apparently it is a very bad camera in terms of connectivity. It doesn't even feature external intervalometer (at least the wired ones), so there is no way to connect it to a computer or mount to increase the exposure times from 30 seconds. Is there a way I could connect it to a computer/mount to increase the exposure time? I have a RPi 4, and I was planning to connect everything with it using Astroberry, but this seems to be the only problem I am facing. There are no cables available for it as far as I can see.

2. SA GTi does not come with any sort of plate (I don't know what it is called) to attach the camera with, would it be possible if someone can help me understand what exactly do I need to buy for it? Something from here would be nice just to give me an idea: https://www.astroshop.eu/mountings-accessories/mounting-plates-and-rails/15_55_50?page=1

3. What other cables would I need other than a USB -> RJ12 to connect the mount to a computer?

4. Would I need to invest in a portable power bank other than the one I have (https://www.anker.com/eu-en/products/a1268?variant=41510216335550)?

I'm sorry for all these questions, but looking at all the options, I don't understand what to get and what not to get.

Thank you everyone for such great input. I do want to mention that I do not know what future has in store for me, but for now I am very much invested in this, and hopefully will be in the future as well. When I was a kid, I saw milky way patch/belt one summer night when I was visiting the country side, and it was etched into my memory until recently I was able to see it again, and that is when my interest in this hobby developed. It was a Bortle class 3 area, and I wanted to capture what I was seeing. I started getting more and more interested the deeper I went into research for that.

Anyway, so reading through all the great suggestions, this is what I have understood:

1. AZ-GTi mount is a good portable mount that can later be converted into an EQ mount by using some add on accessories. It is going to be better in long term compared to Star Adventurer 2i.

2. Star Adventurer GTi is an alternative of 1, except it is dual axis tracker, and goto capability out of the box, but does not have the expandability route that mount 1 has.

Did I understand that correctly? If not, please correct me. Otherwise I have the following questions if you guys don't mind:

1. Is AZ-GTi out of the box a better option than SA 2i? Like this one for example: https://www.astroshop.eu/alt-azimuth-with-goto/skywatcher-mount-az-gti-goto-wifi-with-tripod/p,55177

2. Since SA GTi is an EQ mount, do I need to have a computer and/or guide camera to track on the second axis? If yes then it means without a computer and/or guiding, it will only track on one axis and there is not much difference between this and 2i?

To be honest, AZ-GTi seems like a lot of work to make it function like the SA GTi. If that is the case then I'm more between SA GTi and 2i. Otherwise please correct me if I am wrong. 

6 minutes ago, iapa said:

It has input for 12V power. The power banks for phones tend to be 5V.

I got the pro kit which included a wedge to all it to be used as an equatorial go to mount, there were other bits too. 

There’s generally a number of options on vendor sites, a basic mount only, up to one with everything e.g. https://www.firstlightoptics.com/skywatcher-star-adventurer/skywatcher-star-adventurer.html And https://www.firstlightoptics.com/skywatcher-star-adventurer/skywatcher-star-adventurer-astronomy-bundle.html which just needs your camera and tripod. Can run with AA batteries.

Common comments are around the battery compartment which isn’t the most secure it seems.

Other manufacturers have their own bundles.

 

Are you sure it is 12V and not 5V?

https://www.astroshop.de/fotomontierungen/skywatcher-montierung-star-adventurer-2i-wi-fi-photo-set/p,68887

According to this, it requires a 5V power input. Plesse correct me if I am wrong.

This is the power bank I have:

https://ankerbd.com/product/anker-powercore-select-20000mah-18w-fast-charge-power-bank/

It seems to provide 5V and 9V, and 12V at lower Ampere. Do you reckon this would be enough to power it up? 

Thank you for your input, I really appreciate it! 

Star adventurer sounds like a very good option. A question I have is, can it be run through a generic power bank? I have one that I use to charge my phone, I believe it is around 16000 Ah, will that work? What other accessories should I be looking for? Or does it work out of the box and I only need a tripod and a camera? 

I have a generic tripod for DSLR camera. I am not sure if it can handle the weight these mounts. 

Edit: this is the tripod I have: https://www.amazon.de/Neewer-Camera-Tripod-Aluminium-Cameras/dp/B07N9YY8SM/

Hello. I only have a DSLR camera with kit lens. I've been advised to get a mount so I can get longer exposure pictures. I'm mostly interested in DSO's. I don't want to spend TOO much, but I want to get something that will give me a little room to grow in terms of equipment. 

If the mount has tracking with goto, that would be ideal. And something around 500eur would be ideal. Here are some of the mounts I looked at so far:

The reviews for this one aren't nice, seems to be buggy with it's tracking:

https://www.astroshop.eu/equatorial-with-goto/explore-scientific-mount-iexos-100-pmc-8-wi-fi-goto/p,61886

Skywatcher EQ3: I've read some good things about this one. The only big con being the weight limit:

https://www.astroshop.eu/equatorial-with-goto/skywatcher-mount-eq3-pro-synscan-goto/p,11663

Here are some other mounts:

https://www.astroshop.eu/mountings-accessories/mountings/equatorial-with-goto/15_55_10_40?sort=1#pagination-top

I can get Eq5 listed there, but it is way too expensive. If I don't have to, I'd avoid spending that much on it. But if the difference between the first two mounts and eq5 is huge, I'd consider getting it. But as it is 1k, and with other equipment I need to get it with like battery pack, cables etc it would go way above my budget. I don't want to spend more than 1k. The less the better. I live in Germany, and I couldn't find anything in the used market so far. 

Which ones of the listed mounts would be better for DSO's astrophotography with room for upgrade? 

P. S. Portability would be nice as I don't have a car, and not everything is visible from my backyard due to it being surrounded by houses. 

22 hours ago, imakebeer said:

@Charming Potato

I'm still new to AP only having started in Oct 2022 so feel free to take this with a large pinch of salt, but I have a slightly different view..... When I was starting out I asked for advice which you can read in this thread here.....

To sum up, I don't think you need longer individual light frames - what you need is longer TOTAL integration time, i.e. the TOTAL time the shutter is open, summed up over ALL your exposures (as well as light frames you'll also need to take a smaller number of dark, bias and flat frames, explained here http://deepskystacker.free.fr/english/faq.htm )

To a first approximation at least, and as far as I've understood it, whether you do 1 x 600s exposure or 600 x 1s exposures it doesn't really matter. Longer exposures save disk space, but it's 2023 not 1993 and storage is cheap. I do have a tracking mount now but so far I'm still only using 60s exposures.

A tracking mount is desirable, but no reason you shouldn't continue to work with the gear you already have and improve on your current (and not bad at all!) image while you consider upgrades. For one thing there's plenty you can learn about the post-processing side along the way. However, one thing a static mount won't deal with is field rotation, i.e. your target appears to rotate as it moves across the sky. To some degree your stacking software might be able to deal with this.

I started off with a Nikon D5500 + 18-300mm Nikkor zoom lens, all mounted on my wobbly 20 quid Amazon tripod, and using a manual remote shutter release. I think I was using a FL around 100-200mm, individual exposures up to about 5s long and ISO 1000. Since my tripod doesn't track I recall nudging it round every so often to keep my target centred in the view! I had another play along these lines just recently actually, wide angle at 18mm FL, ISO 400 and 15s exposures.

You can certainly use the 500 rule as a guide, but it is just a guide. You'll need to experiment in practice to figure out what exposure length you can get away with in practice for a given FL.

Once you've done that you can play around with the ISO to get the histogram in the right place - you want the peak around 1/4 to 1/3 of the way from the left hand end. As long as it's not bunched up all the way to the left (or right) then you should have enough wiggle room left when it comes to post-processing in GIMP. Remember higher ISO = more noise so lower ISO is better in this regard.

Something else useful is having something to control your camera to take all these multiple pictures. Your Nikon might have something built-in - mine does but it seems a bit hit and miss. An alternative is a programmable intervalometer remote shutter release, or a laptop running some software such as BackYard Nikon. At minimum you need someway to trigger the camera without touching it, otherwise it'll wobble.

For stacking, you mentioned DSS - I've never used it but it seems popular. Siril is also free and very powerful but as long as you have light, dark, bias and flat frames it's quite easy to use the pre-supplied script for stacking and then follow the tutorial and do some initial post-processing.

For further tweaking, you mentioned GIMP - I haven't needed to go much beyond this yet. I found this video very helpful to get me started:

 

 

Thank you for your input! The skies are clear tonight so I'm planning to go to a nearby park to get something easy to capture. Andromeda is in a really bad spot to catch, so I'll refrain from that, but I'll try a star cluster or a nebula. I'll play around with the settings as you mentioned. Z50 does have a built in intervalometer and that's what I used, as using an external one isn't as simple as plug and play for this camera.

I really want to have a mount, but being a student, no job and 2 terminally sick cats who have very high vet bills, I have decided not to go through with the mount for now. I'll keep doing what I can with what I have, and I really enjoyed doing it. Once I hit the limit of what I can do with this equipment, hopefully I'll have a job by then 😂. 

Thank you for the tip for choosing the ISO. I did not know that was possible (I'm not very familiar with my camera, or any sort of cameras). I'm planning to go out tonight as it seems like it will be a clear sky tonight. Hopefully I'll have good luck again 🤞. 

21 hours ago, Paul M said:

It's a great start. There is much to like about that image. Nice sharp stars, good colour, you got your target plus the bonus prize of a S/N, the background is natural...

Bigger and brighter targets will respond to your "lucky imaging" approach much better than M101, keep at it and hone your skills. And most importantly enjoy this phase of your imaging career! It isn't a contest and it's great that allcomers can share their efforts. 

Find your own niche, this might be it but as already noted by others, a basic tracking mount is almost essential for DSO imaging going forward.

I'm still posting junk, that's my niche! 🤣

Alyn Wallace has done some stunning images with a DSLR and tracking mount: https://www.youtube.com/@AlynWallace

Peter Zelinka has put a lot of time into his tracking mount guides and how his imaging progressed in recent years: 

 

I have been looking into trackers, and I was able to identify difference between azimuth and EQ mounts. I'd rather just spend on an EQ mount than a star tracker so I don't have to worry about the mount for an unforeseeable future (I know nothing is future proof).

Speaking of which, I found this deal: https://www.astroshop.eu/equatorial-without-goto/omegon-mount-eq-500-x-set-with-tracking-motor-polar-finder/p,78169

Is this a good mount? It is in my budget, and I feel like it is much better priced for all the features it has. It even has a GoTo mechanism. Is it bad for me to use GoTo at this point?

38 minutes ago, jjohnson3803 said:

That's a pretty darn good image for your first attempt.  I think you should be proud of your accomplishment.

Thank you! I'm very happy with the results! 🙈

On 05/06/2023 at 15:01, Elp said:

Most of the interesting targets you have to wait until Sept through to winter (northern), and longer nights you'll have no issues getting Andromeda and Orion. At the time being try closed and open clusters which are essentially just stars so will pick up okay.

Iso depends on the camera, it doesn't really do much but increase noise levels the higher up you go.

Regarding time, just try it, you'll see if the stars start to trail quite easily.

Your main issue is:

A. Short exposure decreases the probability of a photon being registered on a pixel (creating the pixel signal response), by exposing longer you increase this photon collection and hence signal. Some DSLRs even have noise algorithms which remove faint signal from the photo when saving (Sony are notorious for this). Your short exposure is also fighting atmospheric seeing, if it's high moisture or temperature the view will be wobbling (like how you see the background shimmer just above hot road surfaces), long exposure will kind of average this seeing out per exposure.

B. DSLRs also tend to have a low quantum efficiency response compared to astro cameras, they also have blocking filters on top of the sensor lowering your ability to capture faint signal, it's why many people with DSLRs use modded ones though this only really helps with emission nebulae.

To capture the faint stuff you really do need tracking, if budget is an issue at the moment you can try diy-ing a barn door tracker, or one of the cheapest ones which work at shortish focal lengths is an Omegon LX.

I am trying to look into used EQ mounts, but I haven't been able to find anything used so far for a good price (or something good in my range). I want to get something that will last me a good while as I want to get some sort of telescope or lens designed for astrophotography later on, so maybe something that can handle a good amount of weight? I've been trying to look for a EQ5 mount as you suggested in my other post earlier this week.

22 hours ago, wesdon1 said:

Maybe try a widefield shot of the night sky? They're very doable with just a tripod and dslr camera. Have you heard of the "500 rule"? Basically, it goes like this...

Divide 500 by the focal length of your camera lens, and the answer you get is roughly how long you can image night sky with just a stationary tripod, without suffering star trails in your images. So for example, I have a 55mm Canon lens, and want to image with it, so I divide 500 by 55, and get 9.09, rounded off to 9. So that means I can image night sky for roughly 9 seconds before I suffer star trails. So you could get, say, 50 x 9 second exposures of night sky, and stack them all in Deep Sky Stacker. Personally, I always knock 1 or 2 seconds off the answer, just to be sure I get nice apparently round stars. 

You could use this easy technique for a while to get some experience in astrophotography, and go from there.

Hope this helps! 

Wes

So I used the NPF rule for calculating this; one online and one in Photopills app. And both of them gave me exposure time of about 2-2.5 according to 100mm lens and that is what I rounded down to 2. I do have another lens which is 15-50mm @ 3.5-6.3 aperture, and this lens' lowest focal point is at 50mm at 4.5 aperture. I'll try both of them next time and see how it goes. Thank you for the suggestion!

I have also did the post processing again for the image, did I do it too much this time? I have played around with levels and curves, and added a little bit of saturation.

9 minutes ago, carastro said:

North America Nebula (this will be a better FOV for your camera), Hercules Globular Cluster (This will be small but doable), Andromeda galaxy when it is up.  Butterfly nebula  IC1319in Cygnus.  The Crescent in Cygnus (NGC6888), NGC6914 if you camera is modified for Astro,  Veil nebula complex maybe, Elephant's trunk nebula IC1396. 

But 2 secs is going to be pushing it for anything. 

Carole 

 

Is it better to use the entire 250mm of zoom on the lens and have higher aperture of 6-6.5 or around 70mm with 4.5? Also I had read in one blog that for untracked photography, it is better to go with higher ISOs compared to lower as it is usually recommended? I believe I can increase my exposure time to 3 or 4 seconds if I play arihnd with the lens. How big of an impact would it be going from 2 to 3-4 seconds? 

12 minutes ago, carastro said:

M101 is very faint, and 2secs won't cut it, especially from a Bortle 7 - 8 location.  You might be able to get some of the brighter targets but tracking, guiding and long exposure is really needed for DSOs.    

The good news is that your stars are nicely in focus, and you have done the right thing with calibration (especially flats) and lots of subs.  

A but of post processing would bring it out a bit more:

Wow. May I ask what did you use to bring these colors out? I'm new to post processing and photo editing in general, so I just followed a YouTube video that showed how to post process galaxy a little bit. What exactly did you change/add to make it like that? 

Unfortunately Andromeda is not visible from my backyard until very late night due to houses in the way. This seemed like an easy target as this was straight up above. Is there anything else you'd reckon be an easy target for me? I have the following targets I can see in Stellarium that are straight up or close to straight up these days: 

North America Nebula, Messier 5, Herculeas Globular Cluster, M94 galaxy are amoung the few. Maybe if there is something else you know that is an easy target? I live in Germany so there is no Orion here these days, which I believe is the easiest target?