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Posts posted by Leonard Abu-Saa
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On 25/01/2022 at 01:41, rickwayne said:
I'm with Olly on this one. You've got terrific optics in that 135; going for more reach may be very frustrating from the start. It is best to start with the simplest thing that could possibly work, and get your whole workflow going. This includes polar alignment, focusing, getting calibration frames, and very importantly, processing.
Is that what I did? <Hollow laughter> No, no it was not. I spent a lot of time dinking around with all the complex bits wishing I'd started more simply.
Thanks Rick, this is my intent too. But first, I want to understand HOW it works and the necessary bits and pieces for the 'simple' work :D. With AP, it's never easy :)) As I mentioned, I am complete beginner in AP, and a bit confused.
Thank you and everyone for your suggestions, it really helped me a lot to make an idea of what's going on.
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20 hours ago, ollypenrice said:
Although this may be counter intuitive, an imaging rig must be built from the mount up. Once you have a sufficiently accurate and stable mount, autoguided, you have a platform which can take deep sky photos. I would advise you to forget working unguided, it is not the way forward. If you got a guided HEQ5 going you could really see what your Samyang 135 can do. It is a superb lens.
At some point you could consider a telescope as well. The humble 130PDS gives great results provided you sort out the collimation. If this worries you, a refractor is easier.
Reality check: galaxies, apart from M31, M33, M101 and the tricky IC342, are small targets needing longer focal lengths, meaning a bigger scope and, probably, an EQ6 rather than an EQ5. However, there are galaxy groups which look good in shorter focal lengths.
Olly
Thanks Olly. It may be counter intuitive if you come from the photography field, but what you said makes sense. For starters I want to reach 1-2 minutes exposures so auto guided camera I guess can wait a few more months.
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20 hours ago, ONIKKINEN said:
If im not mistaken your Omegon 130/650 has a 1.25 inch focuser? If thats the case its not that well suited for astrophotography since coma correctors require a 2 inch focuser, and vignetting would be an unnecessarily big issue if you use your DSLR.
HEQ5 is most commonly recommended for a good entry level astrophotography mount and fits your budget nicely and leaves some money left for necessary accessories. Dont skimp on the mount, so try to resist the temptation to buy a cheaper mount to leave money for other things, the mount is the heart of the operation!
So an HEQ5 + Skywatcher 130PDS + TSGPU coma corrector (https://www.teleskop-express.de/shop/product_info.php/info/p6706_TS-Optics-NEWTON-Coma-Corrector-1-0x-TSGPU-Superflat---4-element---2--connection.html) would be around 1800e. There is a very long thread here on SGL where people image with this kind of setup and many pictures turn out fantastic:
Without guiding you will be limited in the exposure time you can use, and there will be other nuisances you will have to tend to manually like dithering, framing, finding the target etc. All doable but much easier with guiding in the mix. But this would definitely get you started nicely and get good results already.
For guiding there are options depending on whether you have some of the stuff already. If you have a laptop you could use with the scope you will save a fair bit of money, if not you will go over budget for now. If you do have a laptop you only need a guide cam and a guide scope.
Something like the very simple but effective ZWO 120MM. This is conveniently sold as a package with a simple 50mm guidescope: https://www.teleskop-express.de/shop/product_info.php/info/p10396_TS-Optics-Guiding-Set-50-mm-Mini-Guide-Scope-and-ASI120MM-Mini-guiding-camera.html
Guide scopes can vary in price but the differences are in the focusing mechanism. The above model focuses by rotating the lens cell, which could be annoying to do. More expensive models have a non rotating focuser. But focusing a guidescope is not really that important, it just needs to be good enough and you may find it doesn't bother you.
If you dont have a laptop you can spare, you would need to have some kind of computer on the scopeside. Either a used laptop which can be very cheap, a ZWO ASIAIR which is expensive and only allows you to use ZWO products and some DSLRs, a Raspberry PI running stellarmate software, a stellarmate (same as previous), or the best combination of all of these: a windows 10 mini-pc. Prices with these vary but expect to spend around 300 euros or more.
Without the computer you would be right around your budget with the HEQ5+130PDS+TSGPU+120MMguider package, but there will be additional costs, there always is. You'll need an adapter or two for the coma corrector, you would probably want to invest in some collimation equipment like a TS concenter eyepiece, you might need to buy a power adapter or if imaging in a remote location a battery of sorts to power everything. So maybe drop the guiding for now and stay within budget would be a good route to go.
Thank you for the detailed explanation. Yes indeed, my omegon has 1,25” focuser and tbh, not very smooth. I also read a lot from the thread you mentioned, seems the right approach for the moment. Many thnaks
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1 hour ago, bobro said:
It does look as though the Omegon 130/650 has been designed for DSLR photography. The scope has an unusual focuser that is shown on the store website with a DSLR attached. It looks as though a couple of adapters have been removed from the focuser, allowing the camera sensor to come closer to the mirror to achieve focus.
In any case, the OP's camera is mirrorless and has a flange to sensor distance of only 18mm (rather than a typical 44mm mirror DSLR). Bringing the camera to focus should be no problem.
It looks as though the focuser has a standard 42mm thread for a T-ring. Assuming this is the case, a T-ring to Sony E-Mount adapter like this one would be required to attach the camera: https://www.celestron.com/products/sony-e-mount-t-ring
Although the mount looks light and is likely to be a weak point, an RA tracking motor is available for the mount https://www.omegon.eu/drive-motors/omegon-eq-320-tracking-motor-set/p,65804, which should allow exposures of around 30 seconds to be achieved. This would be a useful way of seeing how well the scope performs before upgrading the mount and adding guiding/goto.
Yes, I do have a T ring for my camera and the focuser is with with red dot. If I get 30 seconds exposures for now I will be more than happy. Being a complet newbie I tend to compensate tha lack of knowledge with better equipment
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1 hour ago, malc-c said:
With precise polar alignment the HEQ5 will track for a few minutes before things like backlash and periodic error will cause the stars to drift, so for any serious DSO imaging guiding is a must have option. How you guide is down to you and your budget and methodology. You can get an all-in-one guide camera that you attach to a guidescope. It has the ability to process the image it sees and send corrections to the mount without the need for a computer of some description. An alternative is to use a 9x50 finder scope and attach a camera to it and then use some form pf computer with free software to control the mount and handle the guiding. The subject of what options are available are very well documented in similar threads so I won't repeat myself here. It's worth browsing the forum and reading up on whats available. Whether you opt for an all in one, or a computer based system, budget around £200 - £350 for the guidescope & camera / or scope & autoguider options.
Thanks again for the input. I would very much like first to get to those few minutes of tracking :). So I guess that heq5 for the start will get me started at least.
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3 hours ago, malc-c said:
The HEQ5 has been the popular mount for serious imagers for some years. It's a great mount, and is well suited to all the scopes you mentioned. Whilst you save a small amount purchasing a complete combo of mount and ota together, I would suggest you just purchase the HEQ5 and try it with your existing 130 aperture f5 scope. This would give you an insight into imaging without spending too much money. If you later found the scope under performing for your needs then look at upgrading the ota at a late date. If you want more light gathering for fainter objects then the 150 / 750 here would be my choice, mainly as it to is an f5 so any accessories such as a coma corrector should work with either scope. The f4 154/600 might be too fast, and could need special correctors to give a flat field across the whole image.
Personally, an f5 scope is a nice sweet spot, ideal for DSO imaging. Longer focal lengths, typically associated with SCT's or Refractors are more suited for planetary work, although with reducers they can take stunning DSO images.
Thank you Malcolm for your suggestions. If I stick with my current 130/650 and upgrade my mount to heq5, do I need also an auto cam guider and focuser?
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1 hour ago, Grant93 said:
May I ask why your current telescope isnt suited for AP?
Only things I can spot is you may need to change out the focuser, and you may need to shift the mirror up the tube (Not sure on that one). Just because a telescope isn't advertised as being suited for AP, doesn't mean it isnt Obviously you would still need the HEQ5 or equivalent.
I could be wrong though!
Thanks for the suggestion Grant. I could get the HEQ-5 mount, but I’m not sure about the scope. However, I am unwilling to tweak my current 130/650 because I just don’t know how and what amount of tuning would be ‘enough’. Also, I didn’t find any images posted with this scope compared to the SW 130/150. Assuming I stick with this scope, what focuser and auto guider would you recommend?
Thanks a lot for your input.
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Hi guys, I’m Leo, I’m new to astrophotography and I am looking for advice since I have a lot of questions and a big dilema. I want to build an AP kit and I’m not sure which combination to choose or should I upgrade my existing one?
My current setup consists of:
DSLR: Sony a6600 (APSC) + Samyang 135mm f2 + Star Adeveturer Pro
Telescope: Omegon 130/650 with EQ-320 (https://www.omegon.eu/telescopes/omegon-advanced-telescope-130-650-eq-320/p,61022#tab_bar_3_select). I bought this telescope just to figure out if I would like it without spending too much money, but is not suited for AP.
My interest is in photography of DSO, so I did some research on scopes that would get some nice results and I have a budget of 2000 euro (all accessories should be included).
My options so far:
SW 130PDS https://www.astroshop.eu/telescopes/skywatcher-telescope-n-130-650-explorer-130pds-ota/p,25455 + HEQ5 mount (or even 150PDS?)
Omegon pro astrograph 154/600 https://www.astroshop.eu/telescopes/omegon-telescope-pro-astrograph-154-600-ota/p,54739 + HEQ5 mount. I also don’t know what other accessories like cam guider and filters should be included in the kit for either of the scopes. 🙈
OR
I should buy a longer focal length lens for my camera and stick with that?
I am completly lost and your advice would be greatly appreciated. How would you build your kit in that budget?
Thank you very much, Leo.
Starter kit for AP - telescope + goto vs dslr + star tracker?
in Getting Started With Imaging
Posted · Edited by Leonard Abu-Saa
Thanks Malcolm So first step is learn to align properly
My first attempt on Orion Nebula and Orion's Belt with Sony a6600 + Samyang 135mm + Start Adventurer. 30x15" lights f4, iso 1000; 100 bias; 40 darks. Stacked in DSS and processed in LR + PS.
I live in bortle 6 area, between flats so I can't see Polaris and align properly. I used an app 'PS Align Pro', but with more than 15 seconds exposure I already got trails which tells me that my alignment was extremely poor. Also my editing skills are not that good but I want to improve. If anyone wants to try and get more out of the .tiff file, I can provide a link