JSeaman

Ah brilliant, I thought I'd done exactly that but must have not zoomed enough - many thanks!!

After adjusting the DEC backlash this seems to have gone away, just under 1" for last night which is not bad considering how windy it was!

I set up last night on the cone nebula and checked my PHD logs this morning to see something I haven't before. At about 21:39 I started guiding for 7 hours (and it was indeed guiding and imaging during this time), oddly though the guide log just shows a flat line right until the point where the scope loses site of the target and then I see activity. I have attached the full guide log and extract of the debug log, is this something anyone has seen?

PHD2_DebugLog_2020-02-24_205124.txt PHD2_GuideLog_2020-02-24_205124.txt

Thanks, I did look up the two measures and it looks like I'm in the good area FWHM are <2 and focus is showing as perfect on the Bahtinov

I had about 20 minutes of clear sky last night so did a DEC backlash tighten and it did seem to guide OK but still had an anomaly at the start of the guide log. When we get another clear sky I'll try again

That's much more like what I was after using Ha as a luinance mask, thank you again!

Well we have differing views about black point, I know it's widely popular to avoid dark backgrounds but I like it so that bit stays

Don4l - thanks that's useful to know, I am just starting out in nb so finding my feet.

The focus was set with a Bahtinov and I can indeed measure FWHM, although I've never used the numbers, what does that give over the mask?

PA is something I worked on last time and I considered flexure too and have tied the guide scope down harder

I might well play with the Ha short stack you mentioned and see how I get on - thanks for your thoughts

The O3 was without moon, the Ha and SII were with

The results I'm chasing are the clarity of detail, nothing to do with the black point, that's the very last thing I tweak

There is indeed drift and I have been working on PA - see other thread for the drift alignment I did the next time I went out!

1. Yes I have a lot of time for people like Olly but if something is subjective then that's down to personal opinion

2. Yes and this was focused with a bahtinov mask

3. The moon wasn't the issue as this was nb, there was no rushing only frustration!

The whole galaxy/narrowband was the problem, I didn't realise this was a no go area

Thanks for your feedback though

9 minutes ago, alacant said:

Hi

If you've built on soil and have had a lot of rain or it's been especially dry for long periods, ground movement? Especially noticeable here in summer when the ground dries to quite a depth.

Ha that's a good idea given the current climate but it's in cement for a couple of square metres

I think the scope balance is good

I do indeed dither and you're right, it guides just fine after the initial period

I was thinking about ditching PHD and drift aligning manually, thanks for that. The confusing bit is that the guiding seems OK (not brilliant but good enough) after the initial calamity

Hi Michael, I was waiting about 5 minutes each time

I was only aiming for <5 but ended up pulling it in really well

After a bit more time playing with this last nightI found that I was regularly getting very poor performance in DEC for a few minutes and then guiding resumed as normal. This meant the guide assistant was seeing the bad start and producing some very scary numbers. Example graph attached, note the first big hump in DEC

My guess is that there is a DEC backlash issue or something I don't understand going on 

A few nights ago I went out and spent about 3 hours just trying to sort polar alignment, I used drift alignment and recorded my steps, the abridged version is:

    Slewed to bet cnc which gave me a -3 meridian offset and +9 declination
    I adjusted and pulled the error to -.25
    Next, I went for omi tau which gave -82 and +9
    I brought this it to <1'

I grabbed a quick screenshot of the error and it was showing -0.64' (attached). I thought I had cracked it. 

Tonight I went out and it seemed all over the place so I ran the guide assistance, it now says I'm somewhere between 15 and 19 arc minutes out on polar alignment, see second screenshot attached

Everything is tight, this is in an observatory on a pier and it hasn't been bumped. Can anyone begin to hypothesise what on earth is going on for me?!

Removed the focal reducer, needed the lakeside focuser fully extended and an extension tube to focus but still blobby stars

Just combined it with some old data from a QHY8L, thanks

Scope is an ED80, 600 second (10 minute exposures), between 4 and 9 hours on each filter

Reasons for narrowband are that is all the filters I have, light polluted area, all shot under a full moon

You may be right though about LRGB, not something I have done before

Thanks, it seems you have the same star bloat I have

I'll try and read that as though you're trying to help

If you look at the title you'll see there is one ha one o3 and one S2

By at random I mean from the set that made the cut

The black point is just a matter of taste, I prefer it dark (even in your example). I just mask off anything faint if I want to protect it

I'm struggling with blobs for stars which I've seen a few people mention on the atik 314l so may just be a feature of the camera?

I was hoping for more definition on the spiral arms than I managed, a sub from each filter attached chosen at random, I have no issue throwing subs away if it helps

M51-1_010-1.fit M51O3_010.fit M51_SII_010.fit

I bought it for use with a 70D coincidentally, now I have moved ot the Atik I considered removing it actually.

My stars are quite blobby everywhere in the image but no worse in the corners so guess I'm OK 

Thank you all

Thanks, I guess my query is, if I'm achieving focus does anything need to change?

I could do with a bit of guidance on spacing please, after looking here:

https://stargazerslounge.com/topic/180389-atik-314l-with-ed80-questions/page/2/

I see the recommendation is:

0.85 reducer --> M4/T2 --> 11mm --> T2/M54 --> EFW2 --> Atik 314L+

I currently have (see pic)

0.85 reducer --> Adaptor --> EFW2 --> Atik 314L

I have no problem focussing with a Bahtinov mask but don't know what the effect is of having replaced the bits between the focal reducer and EFW with the adaptor I just happened to have lying around. I've never really thought about it until now!

Note I'm also using the 314L not the +, I am assuming they have the same spacing

James
 

I just don't seem to get the results I'm after at the moment. I've had all sorts of issues with the mount and I'm only getting Tot ~1.5" in PHD2 which isn't helping

The image is with between 4 - 9 hours on each of three filters but I'm not quote getting the detail I was hoping for

Yes exactly that.

I just finished taking the Atik EFW apart and found a defect in the metal ring which holds the O ring so that now runs freely again, I guess that was just coincidence as it was obviously a manufacturing fault.

I've rebalanced everything and set it to the home position by eye and will try and align on a star tonight if I get a chance

Michael - I think the home position has to be set with the clutches, I'm not sure synching works. I agree with your approach and that's what I normally do, I just wanted a more scientific/repeatable approach, I took a big step backwards!

Merlin66 - It was "all sky plate solver"

Paul - I'm trying to avoid eyepieces, I want to leave the camera/focusser/filter wheel attached at all times

Scope is an ED80 per my sig

Last night was a bad night, tonight if I get a chance I'll just do things like I did before and ditch the plate solving

Well that was a disaster, I got "all sky plate solver" working and it was the biggest mistake I've ever made. 

I don't see a way in CDC of syncing to an RA/DEC (you can view it though), I only seem to be able to synch to a target. Even if I could I don't think this will actually do what I need as it synchs one point but the home position is still wrong.

I got it to talk to the mount and it said it had synched with Betelgeuse (verified by it's own plate solving) despite the star being visibly nowhere near

I also found that it screws with all things ASCOM, it killed Nebulosity twice, made my Atik filter wheel get stuck between filters and has caused me 3 hours of trouble for nothing. I've never had any issues like this until tonight and it's going to take me another night at least to sort out. What a bad call that was. 

I'll go back to spending an hour moving the mount around until I find a star next time