bomberbaz

what are the two pictures images of please?

wow, great bit of kit but 5K 2nd hand and much more new. I would be expecting breath taking views at that much moula!

More testing done at request of vendor. (Not that it was needed as under warranty) With and without the FF, the comet star shapes are there. Rotation of the focuser makes the comet stars follow the rotation. V/tired now but will put up pictures tomorrow of the focal train so it is more apparent.

Ok so had a little play tonight and here are my findings. The comet rotates with the camera, one way or the other it follows the rotation. As regards exposures, 180 seconds or 10 seconds, it is there. Not sure if I am right here but this appears to point towards a image train/collimation issue rather than tracking! Oh and sorry should have pointed this out earlier, my previous OTA (which should be tried in place of the horizen) didn't suffer from any such issues.

It is in the same direction is the cometing. Exposure length 3 minutes, my tracking has been pretty decent. In dec it has been very tight, it's the ra thats been naff. Hmm, just checked the Alt clamp, it was quite loose and there was more flex movement than normal. (There is always a small amount but definitely more) There is a built in rotator into the focusing unit, I shall take a couple of subs with it one way then rotate 90 degrees to see if the comet (assuming it is still there after tightening the clamp) rotates too. Anyway, thanks for the pointers gents, think I might be getting somewhere here.

Hello all, I have been having a few issues with my collimation. The scope is a RVO Horizen ED 60 which according to the RVO website goes through rigorous testing prior to leaving the shop. I am wondering if part of the issue is down to my method of attaching it to the camera, see directly below. However I have now removed the std 1.25" eyepiece type connector and attached the camera via a 58/42 screw type 20mm spacer. The problem is the star are comet shaped (see other picture below) and was hoping someone has had this issue before and can tell me outright what the issue was for them, saves me speculating and hopefully allows me to come to a quick conclusion of my own problem. Cheers all steve

That's excellent that Lee, you have captured some very good structure in that. If I had to be picky I would say the stars could do with sharpening up or making a little brighter, you must have a filter for that, haha. But overall and bearing in mind how far you have come it's top notch.

My laser vcollimator is in need of collimation sadly. Actually @Priesters, do you have a properly collimated laser. I would happily drive with my rig up to Colne?

Here you go Lee, looks ok to me though!

Cheers @herne & @AstroNebulee for the replies. I didn't get this coma when using the old evoguide, but also my time was limited to 120, not that I can see taking it from 120 to 180 would suddenly cause this issue as it is quite severe! Yes Lee I have removed the 1.25 thumbscrew type eyepiece socket, didn't seem right from the start tbh. It is all now screwed together, (see below) What I really need to do is a test run with the evoguide and then a test run with the horizen and see what the results are. If evo is good and horizen not, then chances are the horizen, or the light path has a collimation issue. Then it's seeing if the light path is the issue or not to narrow things down further. Although a quick check today shows the light path connections to be nice and solid. I will get there but this is a right blag if I am honest.

I actually think this could be a collimation issue. If you look at the picture below all the stars are comet shaped, facing top left to bottom right. I have emailed the vendor about this so will wait what they say. @AstroNebulee Lee, just have a nosey at this picture for me and tell me what you think, is it the same as yours was?

Turns out there is a full guide which came with the FF, box with it in is now in the loft. Guess where I am going shortly? 🤣

Lee @AstroNebulee, your star issue, I am thinking this is what I am suffering with. if it was tracking, the whole thing would slowly be shifting but it isn't, therefore I am coming to conclusion I have a distance to FF issue. I was connecting the FF via a 1.25" eyepiece socket and using the same connection attached to the camera. I have now removed this and added a 20mm M42/48 adaptor instead which brings the camera circa 20mm closer to the FF. If this improves my image I will know what the culprit was but I am fairly sure I have a distance issue. Also if this does work I will replace the spacer with the filter drawer your using, that way I can slide the dual band filter in and out easier. Did yours need a 2" to 1.25" adaptor for your filter?

Nice view of pendle there, are you up wycoller way?

As per Jonhinderby, it comes with two adaptors, 2 and 1.25. You can then add a 1.25 reducer to the 2 inch adaptor. I was not impressed with the focuser and adaptors when I got my 12" dob. For a few extra quid they could easily have put a decent focuser on instead.

I lengthened my balance bar the other day Lee, useda 2 inch bolt, took around 2 cm to lock up then skid the weights down the extra 1 inch or so. Balanced it bob on.

Lets look at your big positive, your aperture. As long as your not trying to get very faint DSO's, you will probably get a decent enough image of most bright objects with minimal exposure time, say up to 10 seconds single with something like the Triffid Nebula. With the Moon and planets, a quick blast of video stacked and bing, your there. However your going to have to put in a fair bit of legwork finding out what length of exposure and gain you need and make a log because your going to be needing to change it if your making a varied number of objects the subjects of your presentations. I would say however it would be far better if someone were with you to set the exposure and gain settings as per your presentation menu and pre prepared settings guide. This is more for the purposes of continuity whilst you present than any other reason. To be honest a second person doing all this and vetting your image before broadcasting it might be something to consider. I have actually run my dob remotely once albeit from the conservatory and although it worked, my issue became the image size. To show you what i mean see the image demo image below. Your camera in the 14" SW flextube is the small blue one, the larger yellow is the ZWO 183mc and then the zwo183 with a 0.5 reducer to broaden the image size. (Be aware of focus issues with the reducer) So in short there is a lot to figure out but it is doable but as you are finding out, and there is a little more to it than perhaps you first thought. Hope this helps. Steve

Think next time out I will not bother dithering. With my scope FL and fov the walking noise will be minimum and pyastro tools can remoove whats left. I am actually wondering if the dithering is too blame for the drifting. Thanks @hernefor your settings walk through. I will build a settings sheet walk through with tips and pointers for next time out using some of your info plus stuff from my link above. I think taking a methodical approach will help in ironing things out.

Very useful article here on the guide settings including a guide testing method. I have cut and pasted the main part but also attaching the link, well worth a read guys. The next thing we can control is the guiding rate or guide pulse multiplier. In ASIAir this is found under mount settings as .25x, .5x(default), .75x, and .9x. The baseline guide pulse is the pulse sent to mount to keep things moving at the sidereal rate. When a corrective guide pulse is issued, this setting will send a pulse as .25x the sidereal pulse, .5x , etc. Every mount is different and responds differently. Most will find that .5x is perfect but not always so. My Orion mount corrects best at .75x. For some mounts these settings are not offered in the app and must be set on your hand controller. You can determine which setting is best by setting both RA and Dec aggression to 50%. Then try each multiplier setting and watch the total rms number. Wait for the graph to measure the full width of the chart using the selected setting. You can use 1s guide exposure for this part to speed up the process. Choose the setting with the lowest rms error. Note that as of version 1.5.3 this setting is not persistent and will reset to .5x at boot up. Another thing to file in the back of your mind is to consider the guide pulse multiplier as a course setting and the aggression sliders as a fine tune setting. As you try larger or smaller guide pulse multipliers you may need to decrease or increase the aggression to get the best guide. If you find your aggression is too high or low you may need to adjust the multiplier to keep your aggression in the middle of the range. East Wind Astrophotography: February 2021

Yeah it is a very rich field Joe, I am particularly keen to get onto this (annotated) asterism which I have named the christmas tree for obvious reasons. I think I am going to need highish power but after a play on stellarium to check magnitudes, I think much of it is possible.

Ok, it's az which isn't ideal, and your taking pictures of differing levels of bright objects which itself brings it's own problems. (Potentially different exposure lengths, different gain etc) However a good thing is your light bucket like the 14" isn't going to need long to get a half decent image of the things but really your going to need more help from the EEVA section, this is more their territory. What your looking to do seems doable though, although think it is more involved than perhaps you may have thought as this is not really imaging but EEVA as mentioned already.

More tinkering. I checked all my images from last night and it seems every sub had a little drift, not sure why that is. Anyway, and sorry for the deluge of images I am putting up three pics. The first effort from last night with 9 subs. A rework using PyAstro. A further rework of just 2 subs but with a Dual banded filter. Notice the slight star trail on my first effort, this was before I installed and used PyAstro in gimp. The rework below got overdone and I finished up with an Einstein cross on the bright star bottom right. Considering this one below is from just 6 minutes of data (2 subs) I am more than just a bit pleased, possibly a tad over stretched. I used the ZWO dual band filter for this one. Now if I can just get the AZ mount tracking right, I think I will be on my way to cracking it. Looking at this image though, I am amazed at the number of interesting little asterisms around it which I have never noticed visually. Next time out at a dark place I shall take this along with me (inverted as a map) to try and find some of them, although they may be beyond the T350!

You would be stacking to get a more detailed picture of what you looking at. However you mention a remote controlled scope, do you have further detail on that, it will help a lot to kno2 more about your equipment

Sorry do you mean you set your callibration to 555 milliseconds? If so then 9 steps shows that is superb and it shows the maths behind it at least appears good.

Mine is going away in two weeks after my birthday. I would like to try, if I can make rig with the calibration steps set as discussed on other thread and also find out what any others should be ( if there is an equation that is) Useful info here for anyone with the asi air on setting up your calibration settings but i believe this carries through to any mount.