powerlord

so.. maybe... just maybe I'm ok. as I'm using an asi1600/533. the primary jas been 'scuffed' but otherwise ok. It's now waay out of collimation after spider back on, etc - but it looks like if I get it collimated, the cracked off bit will be outside fov of the sensor.

Just dropped secondary on primary. Doing well do remain calm here... And yes that is a massive chunk cracked off.. And I imagine primary is damaged too. ###__£/-/?! //

thanks, but yes that's my point - if you do lock it, then it ain't moving. and different springs are not going to change that it seems to me. I get that with more powerful springs you could not use the locking screws though. But if it can't be the issue seems a waste to change em. I'm thinking now it's more likely the focuser and weight of asi1600, filterwheel, etc. I'm gonna put it back together, collimate it and try it with a basic asi224 direct. stu

thanks Rob./alacant - I've taken back mirror assemble off. 6 screws - 3 push, 3 pull I assume ? with the pulls having springs. but surely, if you have the push all tight, the springs are irrelevant ? or have I got the wrong end of the stick here ?

So update from last night: 1. tried with new top plate and finder mounted to it. still same. 2. changed finder and camera. still same. 3. changed ota to my altair 80ed. issue gone. round stars. So, thanks for headsup @michael8554, but that eliminates any issues with finders. So.. definately the newt. So that at least has narrowed it down. I imagine prime culprit is now the primary mirror moving. and that does make sense with it being a bit out of collimation, since it's new and I imagine it was collimated when I got it. And tbh I remeber I sort of dropped it over xmas - not heavily, but it slipped out of mount slowly from a height of about 1 foot onto concrete - so the primary would have got a bit of a shock/bash. So I think I need to get some new springs hopefully from a uk source that's a bit quicker delivery @alacant but thanks for the link, and dismantle the primary and fit em. Whether it's a spring broken, or something just got loose, if I'm checking I might as well fit stronger springs when I'm in there. thanks all - and IF/WHEN I fix I will update this will remedy. stu

Someone from NASA is clearly following my posts!! yeh yeh that one is better I grant you. pfft https://apod.nasa.gov/apod/ap220120.html

Having read the instructions, I'm going to leave well alone!

I've now just swapped guidescope to my other one and camera to my 120mm..

Top bar made up. Setup outside now and imaging..

yeh it was the fast ones

hi chaps, Most of the conversation above seems to be issues with the high speed filters ? What are peoples experiences of the regular 3.5mm ones ? I was considering getting the 3.5mm Oiii as it's very cheap at 210 quid for the 1.25 and I suspect my zwo one isn't wonderful, as I struggle to seperate out oiii from general light pollution at present. https://www.firstlightoptics.com/narrowband/baader-35nm-ultra-narrow-band-oiii-filter-cmos-optimised.html

Cool - do you have a source for correct springs ?

oh ? i used flats above ok. No different from other otas. waht issues are you having ?

Is GSO same as TS-Photon then ? just rebrand ? Good advice @alacant thanks. easiest is to do top bar and attach guidescope there. tbh that's how my 200p is, I was jjust being lazy using the provided attachment, but its just thin sheet steel - its the likeliest problem point and the easiest to fix. stay tuned. stu

good call! - yup - definately guiding then.

So here's some pics. Not mounted at present. But I've triple checked everything for any movement, tightened all screws. Checked mirrors, etc. All tight. Collimation is out so need to fix that though. But other than that I'm stumped.

Posting this here, as it's too bad for anywhere else! This is the results from my 18 quid 28mm vintage job - stopped down 3 stops. don't look at the stars if you have a nervous disposition. However, I attach the unedited stack underneath.. so you can see how bad it was before affinity photo work. Needless to say, that lens will not be used again for astro ! (it's great for video work, etc with the 6d though). Also, note that I neglected the need for a lens shield to shield from moon reflections!! the raw stacked shot:

One from last night. You don't see this one images often. And trying to do it on a nearly full moon was never gonna be great. I was imaging with my 150 newt. Asi1600 SHO. 150 mins H, 100 mins each of S and O (for what it was).

yeh, you've captured a stereotypical suffolk landscape there. It's amazing more people don't like here tbh. 🤪 stu

it's set to 175mm as it says above. yes, it has soft tipped screws, but there are not external forces on it - the cables are tied to the ota so the scope has no forces on it during guiding. I can't see how they would make the slightest difference. And it's the same setup I used on my C925 and I had no issues with that at all. No, there must be something loose somewhere. I need to double check everyhing. secondary mirror, etc. It must be something simple. 🤔

tbh I've never had issues before as I don't tend to 'stuff' the frame. But last night the targets and FL meant I had to worry about orientation. I just found the easiest way was to image a single sub of the target, look at it.. work out how much I wanted to turn it, and then turn it. it worked fine tbh. stu

it's mounted to the OTA directly. And when I saw I was still getting them last night, I went back out around 10pm and made sure everthing was solidly mounted with no wobbling - ota to mount, guide camera to finder, finder to mount, camera to ota, etc. The FL of the guide camera is set to 175mm and is a svbony 50mm. This is the one I mentioned a few weeks ago says in docs is 190mm, but asiair plate solved to 175mm so I'm using that. Perhaps that IS the screw up and I should have left that as was ? (https://www.svbony.com/sv106-finder/) and yeh, mirror wise, it was calm, and so no reason for that i can think. I did think at 10pm or so I had found the reason though - as the screws holding the focus onto the ota were very loose and you could move the focus tube connection on the ota. it wasn't wobbling, but you could move it.. so I tightened all that thinking id sorted it, but it made no difference at all. As you say, the subs looks exactly like they do when guiding isn't right. which is what is confusing me. Maybe I set FL back to 190 ?

@vlaiv noticed the other day that some of my star shapes were weird in my post of M51. I have the same I think last night. I've attached the guidelog and the relevant subs for that log to show what I mean. My average guiding is very good I think. I suppose I'm wondering if, however short, the peak deviations of 2" and -2.67" (according to PHD2 Log viewer) could be causing this ? And if so - what on earth I can do about that? And if not, what else it can be ? Some seem to show 'blurring' or stars in a direction. Some seem to show a doubling - both of these seem possibly caused by the spikes. But.. I mean.. what can be done about the spikes ? Archive.zip PHD2_GuideLog_2022-01-17_173148.txt

just a note to say, wedges are not the only option. I have 2 azgtis. I use one with an old SW AZ mount (the very lightweight one that is about 130 quid inc tripod), and the other with an old geared manfrotto tripod head. both work extremely well, and were each purchased 2nd hand for a fraction of the price of a wedge and are far easier to adjust precisely imho.

This morning. A bit nippy again..