alan potts

Difficult to answer that question, I have one of most types of scope and at all different price points, I would agree with Shane above, a tracking mount greatly enhances any scope, well for me at least. I find the 180mm Mak that I have is very good on planets and for the money great value, but I would also feel you would want to look at other things. A 8 inch SC from either Celestron or Meade also has many plus points and can be good on other object too, so too can the Mak though this has a long focal length normally. If money is no object my choice would be a 6 inch APO, about 1000mm F/L , good on planets and large enough for other useful work but over 4 grand without a mount.

Alan

32 minutes ago, AstroKane said:

I have read that the 294 struggles when it is cooled right the way down  - uneven cooling against the sensor. I have so far only brought it down to 0 so cannot comment. I plan to run my winter images at -15 at most. I have also read that pushing exposure time too long can again bring up issues. That isn't a problem for me as I have so far primarily imaged unguided at 60's but only plan to run guided images at 180  - I am using an AVX.

I am running 240secs but could go longer with the sky around me. I have had very bad focus issues since I went to below zero which I don't believe is me. OK anyone can make a mistake but when so intent on good work as I was the other night, I find it very hard to believe I made the same bad focus 6-7 times in a 2 hour period. The image I posted above was taken at ambient temperature, so about 15-16c that night and in my books it looks decent, considering I paid no attention to it, it was a test.

Alan

2 hours ago, wornish said:

I had the similar issue on Stellarium.  It can be found if you enable the SH catalogue and look for SH 2-157. 

With my track record of dealing with any form of IT I am likely to re-direct air traffic, I will have a look.

Alan

It is a stunning sight through my 18 inch Dob out here in very dark and usually clear skies, I do feel some target lend themselves very well to HSO, maybe some are only visible in this, though as said this nebula in my books looks better in the visual spectrum, great shot it is too. I did it myself with the Canon with just a little moon about but it is not a patch on yours.

Alan 

A totally stunning capture there, it is amazing the detail you have in the shot, almost as amazing that the two filters can cost as much at the lens you took the shot with, maybe even be more.

Alan

When I started (73) the only comment you would see in a mag or book was Hale 200 inch or the like, great image and very well done, how times have changed .

Alan

Really like the top image, more in keeping with what one would see through a scope with Olll filter.

Alan

12 hours ago, david_taurus83 said:

Try the original data again but this time adjust the threshold slider in DSS until it only detects 100/150 stars. If its picking up and registering noise as stars it wont remove them.

Will try it in the morning, not sure I understand but anything is worth a try. Tried it but went the wrong way with the slider, got scopes of 17,000+ and 3500 stars.

Tried it Dave but it didn't make any difference, 180 down to 30 stars detected. I feel I am going to have to wait for a clear sky and do a few experiments, like captures without cooling and slowing down the cooling. Something is causing me to make these frames out of focus as it is not difficult to use this APT Focus Aid and whilst anyone can make a mistake I don't believe one can make the same mistake so many times in such a short period, when the one thing you are concentrating on is focus, whilst I have had the exact same temperature drops with using the Canon this rarely ever caused a problem for the end result . I think I will also try an image of something lower down to try and reduce or stop possible Crayford focuser slip, which I don't feel is happening, it didn't with the Canon at more than twice the weight, even directly overhead on a few occasions.

Alan

Welcome to the site Vigsoe, I cannot answer your question but have to say it is very difficult to read in that mid grey type, you may find many may not even bother. It would be a good idea if you were to change it to make it more readable. I use to own one of these mgen's but never used it, difficult to buy a few years ago and highly regarded.

Alan

I like the way the yellow/orange is coming through in this, not something I have seen in any of my Canon images but I guess this is the broadband filters showing through, I don't have any of those. At least I found where this is though C du C doesn't list it, at least not on mine. It's a cracking image and looks like its title Goran, lovely work.

Alan

32 minutes ago, steppenwolf said:

I concur, the focus is indeed out if that helps to resolve the issue 😟.

We all agree on that Steve, it is why, I took ages focusing more than 6 times in a session, even i don't do a bad job that many times in a 2 hour period, something else is going on here too. Look how tight the M13 image, I didn't take any time over this at all as the Moon was almost full and I only wanted to see if the camera worked, there is no cooling or Cal frames in this image, cooling  I believe is where my problems are.

Alan

1 hour ago, tooth_dr said:

@alan potts have you selected the correct threshold in DS to register an appropriate number of stars?

Never moved it always been on the same setting, in any case both Jpeg and the other image were on the settiing, forget exactly what it is but I know why you thought that

2 hours ago, symmetal said:

Alan,

From the two Canon images you've just posted the focus is really very similar to the 071 images you've posted. I think when you get the USB3 module installed and use the bahtinov mask which is coming you should find focussing will be much easier and quicker. 

Alan

No they are the 071 subs Alan, I think I am fogging up, Grant suggest maybe cooling too quick, something to look at. Next time I get clear though I am rattling off 8-10 subs of something without cooling on and then I think we will see it is not me focusing. Mask and USB 3 should be with me by the end of the week and the beginning of next, just in time for the Moon.

Alan

8 minutes ago, AstroKane said:

I just thought I would throw in my 2 cents along with some images in the hopes that it might help someone who is sitting on the fence. 

I still have a long way to go, good calibration frames is the next task but I am loving the 294. For me learning how to use a dedicated astro cam via the OSC route has really been great. 

I think your M33 is really good, I'm having a lot of problems with cooling I think, the shot I posted here was uncooled, since I turned on the cooling my images have taken a nose dive.

Alan

Great image though a bit over coloured for my taste, can't find it in CduC .

alan

Just as an added bit of information I have this morning loaded 12 sets of 25 plus files in DSS from my Canon 40 D just to look at the information DSS gives on them.

Not one set of images tails off in the scoring given by DSS, infact 6 of them go up in places not by much but this is conditions I am sure, but mainly stay the same give or take a bit. Same scope same me focusing same everything all 4 min subs. I am fairly sure i never looked at possible out of focus issues on these sets..

The other thing that crossed my mind, a Canon 40D has a shutter firing every 4 minutes that could jolt the focus, an 071 does not.

This is a Jpeg of the best from 45 subs as far as I could both are stretched to the same degree, just once. Something odd about the top centre edge?

Both shots have just a couple of Darks etc.

This is a Jpeg from the very worst of the 45 subs if this helps at all this didn't even register in DSS.

Alan

10 hours ago, symmetal said:

Hi Alan,

Sorry to hear you're still unhappy with your 071. I'm not sure what the APT dew setting does but it's worth ticking the Anti dew box in the 071 Ascom Driver to ensure it's on.

This does warm the warm the window in front the sensor and works whether cooling is on or off.

I agree with Adam in that your image problems are mainly due to poor focus. Why the 071 is worse in this respect compared to your DSLR is odd as the sensors are similar regarding pixel size.

Here's an uncalibrated centre crop of a stack of 4 min subs I took with the RedCat 51 for testing (simple stretch in PS) and the stars are pretty sharp. Flat frames are needed due to the blue drop off towards the edges and alternate pixels having a slight green hue if you magnify the image. I use a Lakeside Astro autofocuser with SGP and it autofocuses every 1 degree temp change. With your large initial temp changes it would be autococusing after every sub or so.

Alan

Alan,

I feel Adam is correct in that poor focus is the cause of this. But in my view something could be causing me to make poor focus, I have used this APT system many times where you focus in and out until first visually you see sharpness then aim for the lowest numbers allowing it to settle . At the moment I do not have USB 3, this will change very soon, I am told this affects Live View rate.

I cannot get my head round how I can focus an image of M13 well, without great care I may add, at least I consider the image above sharp. Then after at least 10 attempts during capture cannot get a sharp focus on an image other than the very first ones both nights, re-focus could well have been more than 10 times too I was paranoid by this point. Even the 4-10sec framing shots were sharp with plenty of stars prior to first sub, I didn't save them sadly

I am not saying I always got it right with the Canon but then I never paid it the same degree of attention most times though it way out performed the 071 so far apart from the M13 shot .

I have anti dew ticket where as it wasn't, and I thought this was the issue. I am going to take an image without cooling again as I believe, rightly or wrongly ,this is where I am having a problem and something here is causing this focus issue. I know I am pretty useless at IT stuff but I find it very difficult to believe I am making the same mistake over and over again, it isn't really that difficult to use APT, even for me.

As it stands even with the attempts to gain good focus in the 2nd nights captures, figures in DSS got worse and worse as the night went on starting at a score of 9000+ and ending at 250 and the last refocus so bad it didn't even register, for me this is something more than just my inability to perform focus as I could see stars were sharp even visually as I has a 28 inch screen as well as numbers from the the APT Focus Aid showing Best at .45 on a star and stopping at that the lowest reading. Clearly it will have look right for me to continue to take another sub

Alan   

8 minutes ago, teoria_del_big_bang said:

The Losmandy 'D' Style Dovetail supplied with Sky-Watcher Esprit 100 ED PRO seems very short. I have not had chance to try the balance when the camera and Filter Wheel are fitted and the focuser extended but I suspect the supplied dovetail will be half way out of the HEQ5 clamp and so think I may need a longer dovetail.

What have other owners of these scopes done regarding this?

Steve

I don't have one but thought the same the other day when looking at the pictures, some cameras can weight a fair bit, I know some of my Eos bodies are over a kilo and some bigger CCD can weight about the same, people use these cameras on fine scopes like this, Losmandy dovetails are not cheap either.

Alan

I am focusing using focus aid in APT, I have always used this with the Canon. It is more difficult noe as I do not have USB 3 and so do not have great live view.

I have a mask coming but not here yet.

The spacing it exact I would say, the same as on the M13 shot, do you agree this looks fairly decent?

Alanh

14 minutes ago, Adam J said:

The red at the bottom of the frame is in the location of the amp glow on the old non pro ASI071mc however once the went to pro and added the memory it was supposed to stop it that chip. However even if its a firmware issue then the darks should have removed it, so other explanations might include a light leak. 

Poor focus would show up as a lack of stars in DSS as the SNR of the stars would drop. 

The only other potential issue is condensation on the camera...but that would show up as a halo on the brightest star too and I just don't see that. 

Adam 

 

 

Not doubting you at all Adam but it was the same me that focused the M13 and the 1st frame of both nights is sharp at least I feel it is, focused the exact same way. Last night I checked focus 6 times in 30 frames and can't believe I am making the same mistake this amount of times. I also checked 4 times the night before. The last time I re-focused was the worst image of the night it didn't even register a number in DSS, this looked spot on using Focus Aid in APT as they all did. The same focus aid used on M13 which to me looks pretty sharp. I am going to try it next out without cooling, the Pelican shot I did I only cooled to zero and focused that once at the start, may not be perfect but here it is. 

Alan

1 minute ago, Adam J said:

Sorry Alan, but when I view that full sized I still see out of focus stars I am 100% sure on this. 

Can you take a stack of dark frames with the camera and post them, you should not get the glow on the bottom of the sensor in the second image you posted (not the one in my quote). 

Adam 

Adam,

That is with Darks 25 of them taken at minus 5 the same as the lights. The image of M13 had no anything, and was not cooled, focused the same way, this is what I don't understand, guiding on these 40 frames last night was excellent. How do you explain the 25 frames with very little on them showing less than 200 stars in DSS.

Alan

13 minutes ago, Adam J said:

How old is your camera? You have amp glow on the bottom and that was only a feature of the very early ASI071, ask ZWO and they should fix with a firware update. 

As for the star size of the stars it is focus. I can see little black spots in the centre of the stars and thats the classic sign of poor focus. I would say you ware some way out. Its possible it slipped after you focused. 

Adam 

Lest than one month old this is the first time I have used it really as I didn't have an IR/UV filter, here is a few frames that appeared focused but look to have a haze across the centre.

Alan

Right I don't know how to up load these to show you the issue. as they are FITS files from the camera.

I was very careful last night to get good focus and the first image was clean and appeared in focus with many star and a tad of colour showing on the 4 minute sub at minus 5 degrees.

It scored 9051 in DSS and other info was:- FWHM 5.79, Sky B 8.97 and 1600 stars detected, it was not even properly dark.

20 minutes later and dark now. 1553 scored,  FWHM 6.09,  Sky B 0.36 and 299 stars detected. Here the picture on screen was very dark and with very few stars visible and Sky B 0.36, is this possible, it was only 24 minutes after almost 9 was registed. then over the next 20 captures much the same slight better and slighty worse. Not once going back to the opening values even though I checked focus 5 times and thought it was good.

Something is going wrong here and I can't see what, when I stretch images in APT to see what I am getting, does this stretch stay as part of the file? I don't believe it does, only every other 2-3 I do a stretch. The best way I can describe the two capture is one looks like 30 seconds and the other looks like 10 minutes. Chalk and cheese.

Anyone got any ideas because when cooling is on this camera is rubbish, and I believe it is me not the camera. I did tick this Dew box in APT settings as well thinking this was the problem

Again here 6 x 4 minutes subs, no Darks Flats, cooling, anything what so ever and not good guiding either.

Camera with all calibration frames, best images picked, cooled at minus 5 and though maybe slightly out of focus, a terrible image. keep in mine the shot above was focused the same way by me, the size of the stars is worse than my Canon Camera.

Anyone got any ideas where I am going wrong?

alan

I misunderstood, never mind still a superb shot.

Alan

That came out pretty much the same colours as mine did with a Canon, except on a longer F/L scope, I like the B&W version very much, lovely delicate detail in there. Great work especially with a DLSR, often considered second best to CCD's and the like.

Alan

Really nice image Adam so detailed. Do you ever wonder after 40 hours exposure what 60 hours looks like, asks he who did 2 hrs 30 mins last night and thought that was a lot.

Alan