alacant

The zwo won't work. Your combination gives only 11mm to play with. The one we linked is the only one which will work with an eos. OAGs give you more good frames on cheap out-of-the-box Newtonians. I don't know why they get such a bad press. They spare you having to carry out many of the modifications we outlined and so save you time, energy and weight. Best of both? Modifications and OAG. HTH

+1. May I suggest a different strategy? Leave the guide telescope until last; it's most likely fine as it is. Working from the mirror cell upwards: fit six 1.6mm wire springs. 3 replacements, plus three passive springs over the locking screws. Leave the latter loose. seal the primary mirror to the cell using three generous blobs of neutral silicone sealant to coincide with skywatcher's cork set the tube rings at least 50cm apart on a Losmandy dovetail tie the top of the rings with a rigid aluminium box secion remove the rubber o-ring spacers in the focuser drill and tap a third screw to the focuser collar replace any metal or metal/plastic guide telescope retaining screws with all nylon types Now you can start to think about the guide telescope. Our preference is direct mounting to the top rail mentioned above. Cheers

As good as any. TBH, the only time we've noticed much difference (and even then mostly at 1000mm and over) is when switching between guide telescope and OAG; more usable frames to stack.

Guiding at 900mm focal length, yes. Otherwise with an asi120 and such a reduced field of view, you'll struggle to find suitable guide stars, especially during the up and coming galaxy season. ASI have an efficient bin in firmware. In the quest for tighter stars, I'd also volunteer that unless the OP has really good seeing, binning the imaging camera would help too, albeit with a dslr, in software. Cheers

Hi If you wish to be certain the guiding is optimal, the best option would be to use an OAG. This has the advantage of eliminating the effects of tube flexure, less than adequate dovetail connection and poor mirror cell mechanics. That, along with binning 2x2 will go quite a way to more pinpoint stars. Cheers

Hi Phew. Wide field shots with a 70% moon! The flat frames haven't worked very well. Best to dither between frames and stack with a clipping algorithm. we find Siril the best at this. We find that with the takumar 55 you really need to be f4-f5.6 to control the stars, and with a circular mask, not the aperture blades. I'd say that considering the light pollution, it's amazing you got anything. Well done.

Hi What is wrong with the images you obtain? Fat or trailing stars perhaps? Are these related to guiding? If not ...

Hi Some nice detail emerging. Keep the camera still and keep adding frames. Cheers

Really? Our saddle has these:

http://www.ayrastro.com/ Rings a... Something... I think we had a visitor from there not too many new moons ago.

Hi We can't advise much on it I'm afraid. The guide stars got obscured anyway. Clouds? You really need a steady night to check if everything is working or -even better- someone else guiding alongside you with a setup which is known to be optimum. An astro club would have you up and running in no time at all. But anyway, before the software can get anywhere near, the mount must be as mechanically perfect as possible. It's always a good idea to dismantle, clean, re-lubricate and adjust (even on a new mount) so as to eliminate any mechanical issues. Then look at balance. Then polar alignment. Then electrical connections. You can then turn your attention to learning the software in the knowledge that any problems lie within. It just has to be methodical, otherwise you'll end up bald! Cheers and good luck.

Hi Try these ratchet lever bolts. You need m8 x 50. Please check the second dimension though.

There is no need. The laser is not inserted into the telescope. Neither does the laser need to be collimated. Please see the explanation here.

Hi Assuming windows or mac (?) Can you connect using the bundled Orion software? You HAVE installed the ssag driver, yes? Anyway... PHD2 has a native driver for the ssag. Start again by making a new profile. The debug log will tell you why the mount isn't connecting. Most probably the cable which joins the camera to the mount is faulty. HTH

Ah, OK but you didn't need one. The method I outlined uses the green one of these. Around €2. Apologies. Should have made it clearer.

Hi Get the lens fixed first, then upload a flat frame showing all the frame. Anyway... You have only shown part of the flat frame so we're guessing. That isn't the shadow of the prism; set it along the long edge of the camera frame. That always appears as a curve in the opposite direction if set as described. To set the prism, back it out fully then gradually push it centre frame a mm at a time. Each push, take a flat frame. Continue until you see the shadow of it. Then back off a mm or so. That's it. Even easier, lose the OAG and use a lightweight guide telescope. Cheers

Yes! That's what they are for. The do not simply hold the lens, they need to be adjusted so that the lens sits square to the tube. Your photo shows one such push-pull pair. You must loosen one and take up the slack with the other.

Hi You're gonna have to re-align the lens with the tube before you can diagnose tilt. Here is hands on with an es triplet... So long as you haven't touched any of the lateral screws and only the three pairs of axial hex screws, you are fine, but you'll have to re-align the lens cell with the mechanical axis of the tube. This is most easily done in a darkened room using a laser pointing centrally and axially into the telescope. Set the laser first by fixing it at the same height as the centre of the telescope on a table and projecting the beam onto a wall. The height must be the same at the table as at the wall. Mark the point on the wall Now interpose the telescope aligned along the axis of the laser (you can do this by blowing cigarette smoke so you can see to align the tube with the beam). Adjust two of the three pairs of screws until the beam hits the same point on the wall. They are a simple push pull mechanism. Blu-Tak or WHY helps kee everything fixed relative to each other. You can then work out how to minimise tilt in the rest of the setup having now eliminated the lens alignment. HTH

The question was about this plate. It is to reinforce the tube around the focuser. Cheers

@laser_jock99's telescope. I would guess aluminium. **Please note that this thread is about the OP's SW 200pds. This particular bit is about a GSO model; I doubt whether the reinforcement plate would be necessary on the OP's sw steel tube.

If you have the tube rings distanced and top-tied on a Losmandy dovetail, a reinforcement plate alone should fix it. But yeah, spot on; the gso steel tubes really are hopeless. Cheers

In our experience, they're few and far between but you may just have found a good sw ds focuser. If so, and you can eliminate it from the collimation drift, keep it. There are flexible rubber 'o' rings (sic) between the focuser barrel and the focusing spindle housing which can deform under load/changing angles. Best removed. Rely on the push-pull of the adjusters. In this case SW have it just right. A nice minimalist secondary mirror support. A far cry from the massive metal versions found on gso and joc. HTH

Hi everyone This was the second half of our night of good seeing. I'm almost at the point where I can say that €300 optics were not responsible for the detail in the galaxy. For sure it's not my processing skills; 15 minutes in StarTools is my patience level... We don't know of any easy method of predicting the seeing. This doesn't seem to bear much resemblance to the actual seeing, so we resort to guiding for a few minutes and judge from that; the flatter, the more focal length we can use. Does anyone have a less time consuming method that doesn't involve changing telescopes in the dark? Thanks for looking. eos700d on gso203 siril startools 4h @ ISO800

Hi Post a photo to show us how you have the camera attached to the focuser.