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Everything posted by alacant
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A 2 hour gap in the persistent March cloud from about 04:00. Seeing Scorpio rise at this time of year gives similar feeling to seeing Orion in August. Noisy, but am going through a denoise-ruins-so-many-images stage, so it's likely to remain so! Thanks for looking. Has anyone else ventured this far south yet this year? 700d + 150 f8 Siril 1.1.0d StarTools 1.8.527
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Hi Indi control panel -> Canon 600D -> Options -> Upload -> sd card HTH
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StellaLyra 6" F/4 or SW 150PDS F/5?
alacant replied to Grant93's topic in Getting Started With Imaging
Spread the tube rings further apart on a ~40cm Losmandy plate. Turn the rings 180º so you can use readily available m6 bolts. Tie the top of the rings with a similar length of rigid aluminium box section. Mount the guide telescope to the latter. 1º mirror. Seal to the cell (to prevent lateral movement) using generous blobs of neutral silicone sealant to coincide with GSO's cork. Leave 24 hours on a level surface before refitting... 6 x 1.4mm wire springs. Three replacements and three passive over the locking screws. Leave the latter loose. Do not replace the mirror clips unless you are shipping. Replace the solid metal secondary support with a lightweight plastic equivalent. I think the 2 speed gso focuser is free of flex and rubber 'O' rings. If you go for the sw, you'll need to address that. A black shower cap. Conclusion. An astrograph worthy of the name which will hold collimation at all tube angles. Here is an example of a modified gso 203 f5. Without, we would not be able to use a separate guide telescope. HTH -
StellaLyra 6" F/4 or SW 150PDS F/5?
alacant replied to Grant93's topic in Getting Started With Imaging
Hi With a non reducing cc, no. There are however other modifications which are necessary/recommended. -
StellaLyra 6" F/4 or SW 150PDS F/5?
alacant replied to Grant93's topic in Getting Started With Imaging
We found that the springs needed upgrading and primary mirror lateral movement fixed as a very minimum. Ours too went back from whence it came. -
StellaLyra 6" F/4 or SW 150PDS F/5?
alacant replied to Grant93's topic in Getting Started With Imaging
Lower contrast and unecessary loss of light. I think it's an error. The 6" gso normally ships with a 50mm secondary. Cheers -
StellaLyra 6" F/4 or SW 150PDS F/5?
alacant replied to Grant93's topic in Getting Started With Imaging
Yes, that's it. That gives rise to another problem in that being so far from the tube end strengthening collar, tightening the secondary spider causes the tube to distort. The only route to a sensible retail 6" f4 seems to be the €1000 TS UNC or an eyewateringly priced made-to-your-specification ONTC. On the former, note the reasonable positioning of the focuser, still however with an enormous 70mm secondary. But hey, tell us otherwise. -
StellaLyra 6" F/4 or SW 150PDS F/5?
alacant replied to Grant93's topic in Getting Started With Imaging
Yes. Apart from the 63mm secondary, that's it. Check to see if that is a misprint. That's the one fitted to the 8" f5 and even there it's oversized. Well, unless you're 36x24 full frame I suppose. HTH -
StellaLyra 6" F/4 or SW 150PDS F/5?
alacant replied to Grant93's topic in Getting Started With Imaging
We'd choose the gso over the SW. TS and omegon resell them. Better focuser, build quality... But remember that at this end of the market, both would need -albeit simple- modifications to bring them up to reliable imaging standard. HTH -
StellaLyra 6" F/4 or SW 150PDS F/5?
alacant replied to Grant93's topic in Getting Started With Imaging
Maybe. According to this guy, the primary to secondary distance is estimated to be 330mm. We guesstimated less. Whatever it is, it was far too far out from the tube to reliably mount even a lightweight dslr, hence our recommendation. -
StellaLyra 6" F/4 or SW 150PDS F/5?
alacant replied to Grant93's topic in Getting Started With Imaging
Hi F4 telescopes used to have a bad press but even bottom of the range telescopes such as the ones you cite these days are easily brought up to imaging standard. The main problem with the re-badged GSO f4 is not the difficulty in collimation, nor the larger central obstruction, rather the silly focal plane position which is further from the secondary than the primary to secondary distance. This not only makes balance almost impossible, but leads to tilt which no amount of fiddling will solve. Hence, reluctantly, of the two, we have to recommend the f5. The GSO f5, which has a far more reasonable focal plane around 7cm from the mouth of the focuser, even better. Just our hands on experience, but HTH anyway. Cheers -
Hi The OP was asking how to disable backlash compensation in the mount. This is a prerequisite before setting up the PHD2 algorithm. Cheers
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n00b question #3: Very uneven tracking with star adventurer
alacant replied to GazK's topic in Getting Started With Imaging
Hi Given the zoom lens' astigmatism and that you are not guiding, the processed image looks good. If you want more good frames, the next step would be to dismantle clean, lubricate and adjust the mechanisms. It's quite simple. HTH -
On GS as @scotty38 On indi-eqmod, in the Telescope control panel, here: On a windows box running eqascom, here:
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n00b question #3: Very uneven tracking with star adventurer
alacant replied to GazK's topic in Getting Started With Imaging
Hi Assuming the drive is meshing correctly and you do not plan to employ autoguiding... What did the processed image look like? Not sure what you're expecting. Guess: the stars remain in the same position from one frame to the next? You really don't want that. Do you have the mirror locked up? Unless you have a very solid mounting, at 200mm, the return of the reflex mirror with a cheepo lens on a DSLR is enough to shift a sa as your gif suggests. Free dither:) Otherwise, soft ground, wind, inadequate mounting, something loose, poor balance... Maybe a photo of your setup along single acceptable and trailed frames would help us if you want to diagnose further. Cheers -
Like it. Nice job. You're almost there... Top rail, seal mirror to cell, relocation of guide telescope, eq6 and a black shower cap are all that is missing. Oh, and tighten those mirror cell screws to get more effect from the springs. That's the tube done. You then have only the focuser and camera connection to go. Unless you plan to sit by the telescope throughout the session, automatic meridian flips are not really optional;) Cheers
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First night out with the EQ6 - R Pro (Star trail diagnosis)
alacant replied to Iem1's topic in Getting Started With Imaging
Hi The connection between the dovetail and the mount could be improved. Maybe consider fitting a longer plate that it be held adequately, so eliminating a source of flex. If you don't plan to use autoguiding and have the patience, you could train the mount to reduce PE. Cheers -
Hi Yes, that's what would happen. The cc throws the focus over 5cm further out from where it was without the cc, so your observations of not being able to focus without removing spacers is correct. So that the cc corrects, you need to leave the 75mm intact and add spacers to move the whole assembly further out. But hey, I doubt you'll need a cc with the 224 anyway. Cheers and HTH.
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Hi Make sure you have the latest stellarsolver. kstars 1.5.8 **EDIT: kstars 3.5.8 will get you there. Slew to somewhere in e.g. ursa major: Capture and Solve -> Sync Now slew back to Polaris and go again. With a 203mm f5 under indi-eqmod, the closest we can get to Polaris is around 50 arc seconds. Make sure your accuracy isn't set too low:
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Imaging Galaxies - get rid of 400/500 fl OTAs???
alacant replied to iapa's topic in Getting Started With Imaging
+1, or lest we forget that the OP has something even better, his 10" f4. We're dslr only. 1000mm is the maximum we've found usable on a regular basis, although at this time of year, the simplicity of our 6" f8s -without the need for any corrector- make them difficult to resist at 1200mm. Throw as many seconds per pixel or resolving inches at us as you like -interesting though that may be on cloudy nights-, our just-get-out-and-do-it approach suggests that the seeing is the biggest (only?) factor in determining how good an image you'll get. What we certainly do not find is that enlarging an image of m101 taken with say a 130pds gets anywhere like the quality of the same target with a 200pds [1] Cheers [1] I've just been nudged. No, it's true. We don't use a 200pds, we use a 203mm f5 from Taiwan, However I don't think the difference between a 200mm and 203mm mirror would make any difference. -
I'm not sure what model you have, but we couldn't get anywhere with a DSLR and this model. We got the impression that for deep sky objects you'd need a well guided equatorial mount. It wouldn't hold focus and didn't follow objects accurately enough. Almost certainly our lack of understanding of this type of telescope though. But hey, with a zwo, you could be talking of an ideal combination for stuff like the ring nebula and other small stuff like globular clusters. Perhaps best not to invest at this stage but instead take it along to an astro club, hook up a zwo and see for yourself. Cheers and HTH
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The most expensive item by far is the dovetail plate which retails at €silly for what is simply a length of rectangular aluminium. A 500x100x15 lump and an angle grinder is all you need. Your local window frame supplier will sort you. Claim a 500mm length of profile for the top of the rings from his scrap bin. 1.6mm springs on AliExpress are around €3 per box of 10. Silicone sealant, even cheaper. Cheers
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Hi If you've somewhere permanent to leave the monochrome attached and loadsa clear nights, then maybe. If you've ever seen anyone setting up a mono camera and connecting it and a fw to a computer, you'll know what I mean. Unless you already have the rest of fw, filters, spacers and cables, I don't think you'll get a decent sized sensor within your 1500 budget though. The gap between what a modern Sony colour sensor can do compared to monochrome I think is negligible. Go with the colour. Just our €0,02 Cheers
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I think most out of the box Newtonians are, but fortunately easy to bring up to imaging standard. The only way we've found is to seal the mirror to the cell to prevent lateral movement, fit 6 stronger springs to the primary cell, set the tube rings further apart on a Losmandy plate and tie the rings using rigid aluminium profile. I think any assessment of tilt needs to assume the integrity of the mechanical and optical components. Only then can you begin to fine tune focuser, secondary and camera mechanics. Cheers and HTH