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chrisv

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Everything posted by chrisv

  1. Nice image, the extra resolution pays off. I've tried using ASTAP for EAA, since that was the only option available in Astroberry by default. I was put off at first, because it doesn't do capture, but in the end, the workflow is not that bad. I've used EKOS to capture the images to a separate folder and configured ASTAP live stacking to read the images from the same folder. Whenever I changed targets, I had to manually change the folder in both places. It was my first try with ASTAP and I probably need to practice a bit more. Two nights ago I've also tried capturing using my Canon 80D, but 24 MP was too much too handle for the Raspberry PI - it crashed due to out of memory in the end. This reminded me that higher resolution, will require more processing power, hence a different setup is needed.
  2. I've had the chance to try the setup (AZ GTI, TS Optics 72/432 and ZWO ASI 120mm) for a night and the results were acceptable. Compared to the 120mm F5 achromat, the stars are sharper, but the overall image quality isn't that much better. The noise level is quite high and the resolution a bit too small. I've switched from Sharpcap to Astroberry (EKOS & ASTAP), hence it's a bit hard to compare the results, but the setup is very portable - I can keep everything assembled and just place it outside. I know that everyone recommends ZWO 290MM, but what about 178MM? It has higher resolution and sensor size, while the pixel size is in the same range. It does have slightly higher read noise, but it's also a bit cheaper at my local astro shop. Is it worth it? ZWO announced some new cameras which will be available later this year and 662MC got my attention - it's in the same price range, has lower read noise (at least on paper), but it's only available as color.
  3. Thanks Rob, those are some great images, way better than anything that I've taken with my previous setup ST120/600. I've decided to go with the small apo option, TS Optics 72 F6 together with AZ GTI. It was a hard decision, since a 10" inch dobsonian would have been great for visual as well, but at least it seems an approach that's more tried and tested.
  4. That was my concern as well. When I started EAA with my ST120/600 on EQ5, I had very good results, but also very bad ones. The small sensor ASI 120MM is very narrow, even for a 600mm focal length, and for a lot of targets, especially when using narrow band filters, there weren't enough stars for stacking. With a small APO on the AZ GTI, I was hoping to address this issue and to have an easier to use setup. Do you have any other scope suggestions, to complement a 72ED and get more resolution for smaller DSOs, without overloading the GTI mount (max 5kgs)? Would a different camera, maybe one with smaller pixels, help? Thank you.
  5. Thank you for your responses. I'm more inclined to go with the 72ED on AZ GTI, but there still is something holding me back. With the small APO I'm concerned that it will be very disappointing for visual use. My current ST 120/600 already provides good wide field views visually, but it's terrible at planets or high magnification, the same areas where 72ED doesn't shine. How much affect does the aperture have for EAA, especially under light pollution? From my understanding, for imaging the aperture will affect the resolution - how much detail you can get, e.g. if the aperture increases and the f-stop remains the same, the focal length will increase - which translates to higher magnification or resolution, depending on the camera sensor size. Is a 72ED APO enough as a main scope for EAA? Would there be a major difference between a 72ED and a 80ED, provided they have the same f-stop? Can you see more with a 72ED APO using EAA than with a 10" F5 Dobsonian visually?
  6. I've started EAA with Skywatcher ST120/600, mounted on an EQ5 (with a DIY goto) and with a ZWO 120MM-S camera. I was very pleased with it initially, since it opened a whole new world. Unfortunately nowadays I can only allocate 1-2 hours for my observing sessions and I find myself taking all the equipment outside less and less frequently. My main issues are, complicated setup - lots of parts, polar alignment, Onstep settings (used for my DIY goto), camera drivers, lots of cables the 600mm focal length is a bit too narrow for the ZWO 120MM-S camera; I wasn't able to observe some targets due to not enough stars, especially when using narrowband filters; I've tried a cheap focal reducer, but the results were very bad EQ GOTO - EQ5 is enough for my needs, but even if the setup only takes me 10 minutes, it's still a lot, if I only have 1 hour available chromatic aberrations - they are not that bad when using narrow band filters, but they are noticeable on bright stars, even in mono (bloated stars) Lately I've read more and more posts from people using small APOs on the AZ GIT mount - the mount is small enough (I could even try to leave everything assembled) and the setup doesn't seem to be that bad. If I can get it to work with Astroberry or Stellarmate, I could have something very light and portable, which could also be used remotely during the winter months. I was considering getting the TS Optics 72ED F6 APO together with the AZ GTI month, but after summing all costs, it's almost the same as getting a 10" Dobson together with an equatorial platform. Of course, it is a different style, but there are some success stories for this approach as well. The 10" Dobson would be a pleasure to use for visual, but it could also work for EAA (maybe with a focal reducer). I enjoy star hopping, but I have some challenges with targets from south, where there are some strong street lights. My observations will be from my backyard (I just need to take everything outside) or from the balcony. I'm concerned more about the setup time, rather than the weight, if I only have 1-2 hours available, I want to spend them observing and not setting things up. What do you think? Would a 10" Dobson on an equatorial platform take longer to carry / setup than a small APO on AZ GTI? Which option would be more versatile, easier to expand? Are there other options I should take into account in this budget? Thank you!
  7. How about the secondary mirror, does it have any collimation screws?
  8. You should definitively do this before buying anything else - telescope or lens. I'm not a reflector user, but from what I've read a lot of people use a Cheshire collimator. It shouldn't be very expensive since it's quite simple to make (you can also 3D print one if you have a printer available). Keep in mind that a fast reflector, like yours, will probably be a bit more tricky to collimate, hence you should dedicate some time to it, especially at the beginning. As for the eyepieces, keep an eye on the used market - where I live, we don't have a big second hand market, but I was able to find a very good deal on an Explorer Scientific focal extender in a pristine condition. Examples that might be a good fit, without spending a lot: BST Starguider 18mm - https://www.firstlightoptics.com/bst-starguider-eyepieces/bst-starguider-60-18mm-ed-eyepiece.html Celestron X Cel LX - https://www.ozscopes.com.au/celestron-x-cel-lx-18mm-1-25-eyepiece.html Explore Scientific 62 or 82 You can also search the forum for other eyepiece recommendations for fast scopes. I think even a Plossl should be better than your current eyepieces. Try to get one for a focal length that you don't currently have (take into consideration the barlow as well), but try to stay on the low magnification side for now (18-25mm). Again, please wait with the purchase of the new scope until you're really certain that you cannot obtain more from your current scope. My guess is that it can offer you more at the moment.
  9. I wouldn't go for an EQ2 mount, the minimum would be an EQ3. An EQ mount is more complex than an AltAz mount, because of this it's usually more expensive. In order to provide a scope and an EQ mount at this price, a lot of corners need to be cut. EQ mount pros (for visual use): it's easier to manually track the object, once it's in sight, you only need to adjust the RA knob Cons: harder to setup: even though polar aligning is not that difficult, it still requires extra time; it's fun when you do it the first time, but you will need to do it (at least roughly) every time; since you're probably in the southern hemisphere, the process may be more difficult heavier: most EQ mounts use counterweights in order to balance the telescope; in practice, this means that you'll need to carry a counterweight almost equal to the weight of your telescope star hopping is more difficult: you cannot rotate the scope left, right, etc. - the movements need to be on the RA and DEC axes. This may not seem such a big deal, but it's not that intuitive to do in practice. Combining this with a prism/mirror diagonal which flips the image on the left/right axis, it will definitively complicate things. the EQ mount will rotate the tube when you move from one area to another; to avoid some odd angles for the eyepiece, you will need to rotate the diagonal or the entire tube itself (i.e. if you want the finder scope in a certain position) whenever you change targets As you can see, there aren't that many advantages of an EQ mount for visual use. Some EQ mounts can be upgraded with tracking motors and even goto, but I wouldn't invest more in an EQ2 mount. Now, as for the refractor choice: I know that getting a new scope may seem exciting (it definitively is for me!), but please bear in mind that it may not really be an upgrade in the first place. Your previous scope is a 114/500 reflector, it may not be the highest quality one, but it definitively has a bigger aperture than a 70 refractor (even if we take into consideration the central obstruction). And for visual use the aperture is one of the most important aspects. From the product images and reviews, the bundled eyepieces seem to be low quality. Have you tried a different eyepiece? If you don't have a better eyepiece, try to get one before getting an entire new scope. Maybe you can find a used one, at a bargain. You'll be able to use the eyepiece on the new scope as well (which most likely comes with very basic ones). Between these two scopes, I would choose the 90/900 one because it has a bigger aperture. If you can get it on an AltAz mount (even at the same price), it will be easier and more fun to use.
  10. To be honest, I would avoid both of them - the 70mm of aperture is quite small for visual use, you probably won't be able to see much besides planets from an urban region. Dark skies would probably help, but at 900mm focal length, it's not very portable (still doable though). At this price range, a pair of binoculars might be a better match - a lot more portable and you'll probably see the same things. If you're not set on refractors, I would also consider this one: https://www.ozscopes.com.au/skywatcher-heritage-5-dobsonian-telescope.html It's sold also as AWB OneSky and has very good reviews. If you're interested only in visual, it's probably the best choice in this price range. If you still want a refractor, I would consider an 80mm F5 refractor: https://www.ozscopes.com.au/skywatcher-80mm-refractor-altaz-telescope.html The aperture is a bit larger than your previous choices (although I don't think there will be a big difference), but the focal length will be a lot shorter - hence more portable. It will be better suited for wide field of views and has the advantage that you can mount it more easily on a motorized mount in the future (e.g. Skywatcher AZ GTi) and maybe even try adding a camera as well. It will have more CA aberrations than your other choices, but you'll see those mainly on planets and brighter starts. A fast achromat that's seeing the stars, even in a rainbow of colors, is more useful than a longer one that's staying at home :). Also, keep in mind that AZ3 is a very budget mount (in the bad sense). It's very light and easy to carry, but the altitude adjustments is really annoying (you have to push really hard on the scope). The tripod legs are flimsy (the thread on one of my locking bolts stripped in the first week of use) and it shakes a lot at higher magnifications (> 100x). It will probably come with a screwdriver and a wrench - you will definitively need those. With that being said, I don't think there any better options at this price range, unless you go for the reflector with the Dobsonian like mount (tabletop). Update: I forgot to mention the exit pupil which is affected by the aperture and total magnification (telescope focal length divided by eye piece focal length). With a 70/900mm scope and a 10mm eyepiece, you'll get 90x magnification with an exit pupil of 0.78mm. Looking through it will feel like looking through a very small hole, definitively not comfortable.
  11. I have the Startravel 120/600 and I'm very happy with it. Yes, it does show some CA, but I don't really find it that bad. Most of the times the atmospheric conditions and sky brightness are bigger problems than CA. There are a few ways to control CA, decreasing the aperture & filters, but all of them have some disadvantages. It's light, easy to carry and kind of easy to store - I'm not very comfortable storing it vertically, hence I always need to find a place to put it horizontally. I've also considered Evostar 120, but since I wanted to try to some imagining (especially EAA) with it, I've decided to go for the shorter focal length. If you're only interested in visual, Evostar 120/1000 should provide better image quality - but you'll lose the wide field of views that are possible with the 120/600. Some nights, when I'm tired and not in the mood to search for anything, I just love to cruise through the stars - even under medium light pollution (Bortle 4-5), you can still see some amazing views (Sagittarius, Scutum, Aquila are some great constellations to start with). If you're more interested in planets or smaller DSOs, a 127 Mak might also be an option. It has a longer focal length than the Evostar (1500 vs 1000), but it has no CA and is a lot smaller.
  12. I've looked at it as well, but the price difference between EQ3 and EQ5 didn't seem that big - between the GoTo versions it's 150 GBP, but EQ3 comes with an aluminium tripod. In terms of payload capacity, at least on paper, EQ3 seems very similar with AZ GTi, with a max payload of 5kg. Although EQ3 seems to be a bit more sturdy. Is there a bigger difference between them in real life? I do have some second thoughts about AZ GTi, I could get it for the price of the GoTo upgrade kit for EQ5. Or even less without the tripod, which doesn't seem that great. But I'm not sure how well ST120 would fare on it - it's not that heavy, but it's a bit long. Other than that, I should probably try to invest some time in making the OnStep goto kit for EQ5. @Surreydocker It's funny that you've mentioned the towel part, I've tried exactly that two nights ago. My best views are SW-W-NW, where the sky is quite dark, except for 2-3 street lights. I've managed to find a spot where they are blocked by vegetation, but it seems that they still create some diffuse light. The full moon definitively didn't help either, but I'm not sure how much from the light was from the full moon versus those street lights. Could you compare the 90 deg prism with the 45 amici one? Is there a big difference in terms of brightness and visual quality? How about the BST 18mm vs the bundled 25mm? It's probably harder to compare these, due to the different focal lengths, but did you notice any big differences? I'm still waiting for my 2" mirror diagonal, since it wasn't in stock. I've also ordered an S/H Explore Scientific 2x Focal Extender, just to try out some different focal lengths. On my last session I've tried to split Izar with the bundled 10mm eyepiece, but I wasn't even close. Later I've searched a bit and it seems that around 150x or more magnification is needed for it. I did manage to split Albireo which was really beautiful.
  13. Thank you very much David for the comprehensive post! And many thanks to everyone else that contributed to this thread. I was very close to ordering a 150P-DS and EQ5 Goto bundle but I stopped on the last step of the checkout process :). A big equatorial mount with a newtonian on top might be a good match for EAA and maybe even astrophotography, but it doesn't seem so great when there's finally a night with good seeing, during a work day when you only have 1 hour. Involving small children would also be hard, since they probably can't even reach the eyepiece of a newtonian on an EQ mount. I probably can't even reach the eyepiece when it's pointed at zenith either... With all that being considered, I decided to go for a slightly bigger refractor: Skywatcher Star Traveler 120/600 with an AZ3 mount. It sure gets it share of bashing due to the CA, but after using it for three nights (out of which only one was with decedent seeing, but with the full moon up) I really don't find the CA that bothering. Yes, you can see it when you push the scope to 60x on brighter targets - e.g. Jupiter, but it's not that bad - in fact, I don't even think someone that doesn't know much about CA will notice it. At 60x it goes away almost entirely if you stop the aperture with the provided cap. It probably is a bit harder to manage at higher magnifications, where CA will be stronger and stopping down the aperture might also cause a noticeable dim effect. The scope also comes with an amici prism, which I suspect also causes some CA of its own. The bundled 25mm eyepiece is decent, but it provides only about 24x magnification, almost the same as my binoculars. The 10mm eyepiece has a 60x magnification, but the eye relief is also quite short. For now, I've ordered a Skywatcher Deluxe 2" mirror diagonal which hopefully will also improve the image quality. I am a bit concerned about the lack of inwards focus that some users have reported when using 2" diagonals, let's see how it goes. As for the EAA, I've decided to take things slow. I've ordered a manual EQ5 together with the telescope, so that I can practice setting it up, polar aligning and maybe even switching to it instead of the humble AZ3 for visual. In terms of quality, even though EQ5 is still a cheap mount, it's definitively in a different class than AZ3 - the quality is much better and it seems more refined. But to be honest, I didn't even try it outside yet :). I was more interested in trying out the telescope than the mount. I'll probably try it out this week, if the weather permits, so that I can get a feel of the entire setup and how much time it would take. I do plan to upgrade EQ5 to goto, but now I'm trying to decide which approach to take: the SynScan GOTO kit seems like the simplest option, but paying 400 EUR for two stepper motors, a control box and a handset seems very expensive. You can get a decent 3D printer for half of that money, which has more parts than this kit (and some might even have better quality). I'm also a bit concerned about the noise, since it uses metal gears instead of belts and in most videos it sounds very noisy. The other approach would be an OnStep kit, which seems to be doable for 1/4 of the money. However it requires more time investment and considering the current world wide situation, it will probably be a bit harder to source some parts that are not available from Europe. I'm comfortable with electronics and it really seems like a great project to try on, but it will probably take me a few months to complete it. Overall, I'm quite happy with ST120. Its main down sides aren't that bad and the form factor is quite good. It's really a joy to be able to sit comfortably on chair and admire the views through it, something which is not really possible with other mounts and scope types. I do have to mention that the comfortable part applies only to targets between 10-45 degrees altitude. Higher targets are no fun at all, due to the 45 degree amici prism, but hopefully a proper mirror diagonal will fix this. My next steps would be to add goto to EQ5 and get a dedicated astro cam (I'm looking at ZWO ASI290 mono at the moment), but I'll probably take my time with these.
  14. I agree about the goto mount. It's something that I'd like to get from the beginning, or definitively as the next step if the budget doesn't allow. My main concern was that most budget friendly Alt AZ goto mounts have a max payload of 5kg, which limits the scopes that they can be used for. The next options with higher capacity would be cheap EQ mounts that can be upgraded to goto (EQ3, EQM35 or EQ5), but they require more time to setup. Celestron SE line was on my list, but I dismissed them due to the price and high focal lengths. For the price of a Celestron 5SE, I could get an 80ED APO with an AZ Gti mount (goto). For visual, 5SE might have an edge due to the large aperture, but how would they compare for EAA (deep space)? I've also considered a goto Mak 127/1500, which is a lot cheaper than a 5SE ($690 vs $1263) locally, but I dismissed it due to the long focal range.
  15. I've spent the past few weeks trying to decide on an EAA setup that could be started with a lower budget and upgraded without throwing everything away. I feel that I've reached a standstill at the moment and it would be great if I could get some advice, just to be sure that I'm going in the right direction. My goals are, - Focus mainly on DSOs. - While the main focus should be for EAA, I would like to also involve my two daughters (my oldest one is 5 years old), preferably for visual. They probably won't have enough patience to wait until I polar align and star hop, although we could work something out. - I don't have any plans for astrophotography at the moment. I do have a DSLR, but I'll probably get a dedicated CCD/CMOS camera. - It will be more fun if it involves some technical aspects, that's one of the main reasons why I would like to focus mainly on EAA. I don't mind the technical complexities, but I'm not much into repetitive work. - I'm not that much into buying and selling used, hence I'd like a more versatile setup, where each piece could be upgraded individually, or repurposed. - Besides the electronic parts, it should be something long lasting. Besides this, my main constraints would be: - Since most of my EAA sessions will take place when I'm tired from the day, it would be more appealing if I don't have to lug around a heavy Dobsonian mount. My main observing location will be from my backyard (Bortle 6) - Budget for the scope and mount around $700 USD. For the CCD, I was thinking at ZWO224MC or something in its price range. I am also open for mono, maybe ZWO290MM, although after reading a bit more, I'm not so sure about the advantages. - I already have a laptop and since I'll be observing from my garden, I should be able to power everything. At the moment, I have the following options: Mount: AZ GTi or EQ5 (without Goto in the first stage). Since my budget won't allow for an EQ mount with Goto, I'll probably focus more on visual at the beginning. I will add a Goto upgrade kit later, but I'd like to test the waters first. AZ GTi has max payload of 5 kgs, unfortunately I can't find any other cheap AZ mounts with a higher payload. EQ5 seems nice, solid and I'd love to learn to polar align, but I'm afraid that it may become tedious, especially when I'll have less than 1 hour observing time. It's also seems a bit bulky and I'll need to figure out a way to store it. HEQ5 is too expensive at this stage and I can't find a manual version that can be upgraded to goto later. Scopes: Skywatcher Startraveler 102/500 I've seen it recommended a couple of times, although I'm not sure how usable it is for EAA due to the CA. It may be a bit at the limit for AZ GTi. Skywatcher Evostar 72ED Small for visual, but it's probably better suited for a light goto mount, such as AZ GTI. It comes in a bare kit, after adding all the accessories (diagonal, finder, eyepiece), the price is close to the next option on the list. Skywatcher Evostar 80ED It seems like a great option, although I won't have any budget for a mount. Even though I wanted something that could be upgraded individually, I doubt it will be of much use if I need to hand hold it. I could try to extend a bit the budget to cover an AZ GTi mount, but I'm also a bit worried about the weight. Also, this would bring the budget to over $1000, which also bring other options available. I've added 80ED to my list after seeing how great it looked in a review. I've seen a cheaper version without a microfocuser and accessories (I could get some cheaper ones), but I'm not sure if it's a good idea. Skywatcher 130/650PDS Probably a bit heavy for the AZ GTi mount, hence I'll need to go for an EQ5. Collimation seems something interesting to do, but it's not something that I'd like to do very often, especially when I have only 1-2 hours of observing time. I've read that it might be a bit more tricky to do at lower focal ratios, hence it may require extra equipment with an extra cost. Bulky to setup, especially if I need to mount it on an EQ5. I've read that mirrors need to be recoated after a while (> 8-10 years). Small Newtonians (< 130mm) Most models seem to be of cheap quality, with too many compromises. What are your recommendations? I know that my budget is very limited, but I'd like to be more conservative at the beginning. I'm not much interested in visual, my seeing conditions are not that great and I also have a light astigmatism which is more bothersome when I'm tired. Thank you
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