wornish

I recently got the HD925 and the ASI290MC. So far when imaging Jupiter I find I get more detail when NOT using my 2x Barlow, and staying at the native F11. But I have learnt from Vlaiv in an earlier post that in non-perfect seeing conditions its best to go for slightly longer exposures of around 6ms to get the best details. I don't think there is one mathematic ally correct answer as there are so many variables. Practice and experimentation certainly pays off.

Had another go last night. This is using 317 gain and 6ms exposure best 5% of 20000 frames. Think its a bit better but still not what I hoped for

Excellent news. Yes mine is the one called ZWO IR Cut. Update: The box says IR Cut but just looked at the actual filter and printed on the side it says UV/IR Cut so that's good news.

Thanks for the extra info. The filter I have is the ZWO 1.25 IR Cut not the UV/IR Cut. I am going have a go with it removed to see if it is contributing to the blurring. Depending on the outcome then will get the UV/IR cut as you suggest.

On my refractor I have an electronic focuser which works great. But on the HD925 I am using my eyes and manual focussing. I got the scope specifically to have a go at planetary and lunar imaging and was aware of the focus challenges. This why I also got the Baader Steeltrack focuser to try and make manual focussing a bit easier. I use the built in focuser on the back of the scope to get the best focus I can and as you say the image does jump around all over the place when adjusting it that way. But then I use the fine adjustment on the Steeltrack to try and get even sharper focus and using that method the image stays put. As the scope is new I haven't tried to do any collimation and when I look at a star it seems to be OK. But I think you might be right getting it spot on is a challenge and not helping. The focus assistant tool in Firecapture and the one on Sharpcap don't impress me but I haven't really had a serious go using them. I see the images posted on here and get so frustrated that I can't seem to get anywhere near the level of clear detail they show.. I know some are taken in other countries and that the jetstream is a nightmare in the UK. But there are people who live in nearby counties to me that seem to be able to just nail the imaging. It's all part of the challenge and fun and it would be boring if everything just worked:) I might take the advice posted earlier and get the Atmospheric Disturbance Corrector. Would like to hear from anyone that's using one if they really do make a difference, ideally with pictures to show an image taken with and without one.

Thanks for explanation. I will do at lest a two minute run first and push the exposure time up to 6ms and perhaps drop the gain a touch. I have tried to keep the histogram at about the 70% mark up till now but I think I will push it towards 90% to see what happens. If conditions allow I will have a go at a 3 minute run as well. One thought could the IR cut filter be affecting the quality of the image? I have seen others say the camera benefits by using one hence I fitted the ZWO one right next to the sensor. Think I will splash out on the ADC as well.

Managed to have another go these were taken at Gain 317 exposure 4.16ms. ( pushing it to 6 maxes out the histogram and everything seemed to be just white so didn't give it a go) 22000 frames. Best 5 %, 25%. and 80%

Thanks for your help. I will re process in AS3 again. Think I might've another go tonight as its forecast to be good seeing again and that happens once a blue moon here.

Thanks for the suggestions. I only used about 8 align points. I have attached the raw stack as tif file 2020-09-13-1932_1-DT-IR-Jup_ZWO ASI290MC_Gain=401(off)_Exposure=1.4ms_lapl6_ap30.tif

I did increase the image size in PS. The original was 640 x 480 I have attached it here. I wasn't using a Barlow. The details of the file created by FireCapture are: 2020-09-13-1932_1-DT-IR-Jup_ZWO ASI290MC_Gain=401(off)_Exposure=1.4ms.ser The output info from AS3 was: ASI290MC_Gain=401(off)_Exposure=1.4ms.ser Stack quality 0.00000000 Median quality 51.22 ( quantiles 47.68, 51.22, 55.87 ) Frame count 33703. The image was a stack of the best 10%. I did have the ZWO 1.25 IR Cut filter in front of the sensor but that would make things better not worse I hope. Seeing last night was the best for months, an 8 on the scale from 0 - 10 as published by met check http://www.metcheck.com/HOBBIES/astronomy_forecast.asp?zipcode=Congleton&locationID=57638&lat=53.2&lon=-2.2

Had another go last night and think I am making progress but I can't seem to get any of the detail others on here do. This is taken using Firecapture with my ASI290MC on my HD925 best 10% of over 20000 frames stacked in AS3 and Wavelet sharpened in Registax6. What am I doing wrong

Like you I set up my AZ-EQ6 each time close to my house and do have mains power available. I use a Skywatcher Powertank 17Ah for short runs to power the mount, dew heaters, cooled camera, focuser and a Raspberry Pi. With everything full on it for it will last for for about 2 hours. If I want to do a longer run then I use a mains power supply. I got one that provides 12V at 30 amps and is waterproof. I put this in its own plastic box as a double protection against dew as you can never be too careful when mains is around outside.

Me too. Looks like Sunday might be the next chance🙏

Thanks for this it seems to be exactly what I am looking for! I have been struggling in poor seeing conditions and starting to worry why I can't get the detail I hoped for on planets. It's the first time I have heard it called the Nominal Back Focus. I will read with interest.

Didn't mean to mess up this topic sorry. Seperate thread started.

But is it the best possible focus? What is the back focus figure meant for ? and does it change with the focal length setting?

Starting this as a separate thread as requested. I am struggling to understand what the published back focus figure for my scope actually means. According to Celestron the back focus distance on the Edge HD925 is 146.05mm. In the base config (pic 1) the distance to the sensor is 80mm and I can achieve focus using the Celestron's main focussing knob. If I use the Baader fully retracted the sensor distance is 115mm. (Pic 2) Again I can achieve focus by using the main focussing knob on the scope. So what is the 146.05mm all about? What am I missing? If I then add a Barlow in to the mix the same thing happens.

Certainly need more info. Operating system ? Windows - XP, 7, 8, 10 ? PH2 ? do you mean PHD2 ? What computer are you using ?

I only do astrophotography, no visual, and have recently bought a C9.25 and a a Baader Steel-Track focuser to help with planetary shots. The focuser is certainly well made and a quality piece of engineering, but it seems to create more issues than it solves. The whole back focus definition seems to be a mine field and is driving me crazy at the moment - what does it actually mean? The main focus knob on the C9.25 moves the backfous well before and after the so called published distance. I really don't understand what's going on! I guess that to to achieve the published focal length the back focus is as what is published but that does not mean you can't get focus at different distances. - or does it? I would really like someone to explain ??

Glad you got there in the end. Have to say stories like this put me off changing to an iOptron mount.

Excellent images. What gear did you use?

As said, you need to change the mode in PS to use 16 bit rgb. Its probably set at 8 bit and that's why you get the banding effect. One word of caution some filters and plugins for PS only work in 8 bit mode so will be greyed out/ won't work in 16 bit.

I just tried to update mine and it says no updates available - strange.

Great images. I have the ASI290MC on order from FLO. can't wait to give it a go.

Plus 1 for APP. It just makes creating Mosaics so easy.