Grant Fribbens

I have the same setup but have not tried it without a flattener yet but I have got a HoTech SCA Field Flattener to try out that arrived last week. If the 294MC sensor size is small enough to avoid the curvature of the field the you might be fine using the normal focal length of the GT-81. I use a APS-C size sensor and I think I would see curvature without a field flattener hence the HoTech SCA Field Flattener. Just need some clear skies!

I think the RedCat 51 with the SkyWatcher Star Adventurer Pro / iOptron SkyGuider is a great combination as it is light weight enough and has petzval design means that the field is nice and flat and the colours will be really good and at 250mm focal length will be easier to handle. With the ZWO F4 30mm guidescope and a ZWO 120mm Mini you can also do autoguiding easily. This is the setup that Peter Zelinka on YouTube has used for quite a while with very good results.

I started out with the Zenithstar 61 but it is only a doublet but it does have FPL-53 glass and you can get a non-reducing as well as a reducing flattener which gives you two focal length options of 360mm or  288mm and I found it was really great starting out. For imaging a triplet or better is good so the Sharpstar 61 EDPH II is great but the only issue is you would have to use it with a flattener/reducer 0.8 for a focal length of 275mm and you may find the wide field of view an issue. The RedCat 51 has superb optics and would not need any flattener as it is of petzval construction with a flat field and had a focal length of 250mm. The ZS61 and 61 EDPH II are easier to add a focusing motor and may have a longer focal length than the RedCat 51 so it is all dependant on the targets that you want to go after.  HTH

On 01/03/2021 at 18:56, discardedastro said:

Well, did a manual calibration bang on the equator/meridian intersection and got similar wonkiness alerts. But only the second time. Backlash as measured by the guiding assistant appears fine (450ms correction pulse). So thinking some mechanical still. I'm not sure what a wobbly OAG/guide camera might look like but that's one possibility (though the revised ZWO one is pretty solid, with grub screws cinched down) and beyond that it's got to be something more fundamental.

Maybe this is the year I get the courage to do a rebuild and replace bearings etc. It has sat out in wet and unpleasant conditions (under cover, but still) for best part of 3 years now.

I have had my EQ6-R for a while and started to get issues like you had in PHD2 when I put on my GSO 8" RC. So I have decided to take a look and found that I could feel backlash in both RA and DEC so have tightened this as per the video which was done by Cuiv, The Lazy Geek. Then I also checked the status of the belts and sure enough found that using the hand controller on rate 2 had quite a lot of backlash on the RA belt similar to what this chap, Rosco Bird DEC backlash, had. So I adjusted the belt tension slightly (1/8th of a turn clockwise on the grub screw after loosening the stepper motor screws) and it has made it so much better. 

I started out with a ZS61 as my pictures with a 55-210 Zoom and x2 teleconverter had reflections. I liked the fact that there is a non reducing flattener as well as a reducing flattener available which some telescopes just do not have the option of or you have to use a generic flattener and go through the process to get the correct distance dependant upon the focal ratio of the scope that you are using.

I use a one shot colour camera I have been finding on the histograms that even though the ZS61 has great FPL-53 glass that one colour was always a bit bloated as not all wavelengths meet at the same place and have got areas of CA like you have from your M42 image which are the blue colours around the stars. I have now moved on to a triplet (WO GT-81 IV) which I can see from the histograms has really sorted things out. I would expect this would not be a problem if imaging in mono as you would re focus or have offsets when you change filters to make sure that the wavelength you are after is always spot on focus.

The great thing is that since I have started other manufacturers have been producing some great triplets like the Sharpstar EDPH series. They are more tempting now that they have also got matching field flatteners rather than their generic field flattener but the are all reducers. The downside to a triplet is the extra weight and the fact that a 61 sized triplet has a lot less focal length than a 61 doublet and when you have reducing field flatteners then the focal length gets much smaller, great for wide field of view targets.

The grub screws should always be tightened onto the flat part of the shaft that it is going onto. Once the focuser is attached you should not be moving the focuser by hand anymore. If you need to manually focus and you do not have computer control then you would need to remove the grub screws on the coupler, but remember to re align the flats on the shafts when you tighten up.

I have gone for a GSO RC 8" for galaxies and then just use my WO ZS61 for all my wide-field except I want to upgrade from this fine doublet to a triplet for better colours in my images.

APT is having the focus routines overhauled at the moment but it is getting closer to what N.I.N.A. has. It is probably better to try out the latest beta @ https://www.astrophotography.app/betaversion.php and look at the documentation on the forum @ https://aptforum.com/phpbb/viewtopic.php?f=16&t=4313&start=180 as it is a little bit more complex than N.I.N.A in that regard but it is getting so much better. I keep trying them against each other with my EAF.

Hope you have some clear skies and looking forward to you posting some nicely focused images!

The coupler should only have enough shaft from the focuser such that the grub screw can be tightened up on. The same goes for the EAF shaft should only go in so that the grub screw can be tightened up on the flat part of the shaft. This will allow the coupler to work properly even if the EAF is slightly off center.

Well done on your decision. I am in a similar position wanting to move from a doublet to a triplet but cannot decide on which one as there are so many options. Hopefully the stock issue will improve this year as we come out of lockdown and things return to a bit more normality. Looking forward to seeing what you get on your first light when it arrives.

The only stacking software that I know of the would work on iPhone is Affinity Photo. The only issue is that stacking astrophotography images also requires that the images must get aligned and only the following software can do that:-

Free Software

Deep Sky Stacker (Windows only)

Siril (Linux, Windows or MacOS)

Paid Software

Astro Pixel Processor (Linux, Windows or MacOS)

PixInsight (BSD, Linux, Windows or MacOS)

Hope that helps

I think it may help with longer exposures on the guide camera otherwise you will be fighting the seeing. I usually go for 2.5s to 3 s. This is after reading this article https://astrobackyard.com/phd2-guiding/

I started with DSS and when I tried the trial of APP I was hooked. Here is my latest where I have tried using the HOO palette.

Great looking image. Yes this is quite normal for these types of cameras. With Astro Pixel Processor and a full set of calibration frames these then are minimised in the final stacked images. It is then down to post processing in software such as Photoshop. Obviously PixInsight can also do this and is incredibly powerful and this makes it more complex and something I want to try soon. I also use Topaz DeNoise as my final part of the workflow which does a great job.

I have got into Astrophotography properly back in December 2019 when I purchased a used EQ5 from here and also went for a WO ZS61 scope. I soon migrated away from using my Sony A6300 as it could not be automated very well and then the usb connection broke so I moved onto a ASI183MC which I have really enjoyed. I knew that I wanted to upgrade the quality of the mount so sold the EQ5 and went for an EQ6-R PRO and have really enjoyed the experience. I know that if I went Mono with filters then I would get better images as the trouble is now I want truer colour than the ZS61 can provide and can see that not all colours are getting to the sensor in equal amounts and when I look at the wavelength diagrams I can see why this is so. I am staying OSC for now as my wife says I spend too much time on this as it is!

So I am looking at moving over to a triplet and am looking at options between 70mm upto 100mm depending upon price but it would seem that the market is shifting at the moment.

There is the usual triplet seems to be where the objective lens is FPL-53, but now it seems to be the fashion to be using two ED or super ED lenses inside the triplet.

There is also the issue of the fact would prefer to go for a scope that has a matching flattener in 1.0x and 0.8x as I do not trust that I would be able to adjust a universal flattener to get the best images.

So I am now looking at the following options and trying to see which ones are better and wondered on what opinions or experience others have had.

• Sharpstar 94 EDPH with f4.4 flattener (would require 74mm to 68mm adapter to fit the TSFlat2.5 for 1.0x)
• Askar FRA400 (built in field flattener) FRA72 0.7x reducer
• William Optics GT-81 IV with 0.8x FLAT6AIII (no 1.0x flattener available Hotech SCA Flattener?)
• StellaMira 85 (not sure if the 1.0x and 0.8x flatteners can be screwed onto the focuser as I do not like compression fittings) long delay on supply
• Skywatcher Esprit 80 or possibly the 100 much larger and heavier than my ZS61
• TS CF-90 Some suggest this the the same as the FLT91 but it has a 2.5" focuser and FPL-55 lenses
•  William Optics FLT91 with 0.8x FLAT6AIII (would have to remortgage for this one! But it is really nicely made)

With all the supply shortages it is not a very good time to be deciding to buy but at least it allows me to make a less rash decision.

Anyone else got any thoughts that could help me?

For a fan you are looking at around 24AWG which you will also find between 22AWG and 28AWG in ethernet cables. Here is a link on Ebay for cable of different lengths that will help.

https://www.ebay.co.uk/itm/Flexible-Silicone-Cable-Wire-1-METRE-8-10-12-14-16-18-20-22-24-28-30-AWG/264413293068?_trkparms=ispr%3D1&hash=item3d9042aa0c:g:yKsAAOSwWuldPtUU&amdata=enc%3AAQAFAAACcBaobrjLl8XobRIiIML1V4Imu%2Fn%2BzU5L90Z278x5ickkXKoKcbeZcOrOku%2BoOBl%2BS4IZUd7WzAPonnZws86NL6N4OZi4dZn70tQnGAV3MgO0owE2ZrnIwNsKXiSrZUGJTjjUwXuVIgYMVL1oHLfQtk%2BcyJaOyxXMcr7wgqX65uq5Hn%2B779CnQpQKmH5eJGL5vyXEQbQk4w5%2Bw3%2FvOfl%2FkzEkHJqxHhHGCX5RAtBaJcXxuSpBTd7g8AqRwSdnFzZAidL%2Fv6wY3tLT28m3VrHneAfMvNuenjATFqsH6An2pPFPAmGAF%2Be%2FjGGOBe5W6ryJ6SPAzW%2BAEk3Bd6CYoSKyry9l9wTmDsroeCZjJI%2BDATcaksKaxtBMqypUD4YMPjTGDRyq0tTdeR80x%2BEWbfp%2F%2FIjPdc9Y%2BflRut6EAE38HHiHFgXQUQo2CocZUDq%2FO%2Bl1pwdU68IfSVDzKrOpFQ9Cc0OUIFvum39i4Fw1mTfN9daJtNTGsEBevJVk7zFV39OjFk4rEQj3wqMXk9lBg4MdASPfAramefEYaD2nInNFlgoMXfBe8H8vuxNVCJgcyVeOuL7tspfFFBTdGWNpm%2BeujfHqOXfbk7nTYLmKfC%2BqxGwjR4LBCAk%2B9WX%2BoiAs1FC5xblmkIv2DKuy3kKb759guHRxkLoxnRBQxUFFoyvsQJguctKjlOucK%2FZ7F4wu9gtd0NgaOGi03JreRT0V3Z5REuR8liMOGakj4B%2FAyiNxp%2Bru1m16lSBV2sirlcsbWPRT50u%2BOOYXb64pWAkgH10g2VMCq2Z1r6Mo26nw3SEebs04Br635TgZp65224Kf7YIksg%3D%3D|cksum%3A264413293068a07b0f0eeede47fe99ea685912fb5322|ampid%3APL_CLK|clp%3A2334524

On my printers I have ran an 8 core 26AWG cable which can then be used for nozzle cooling fan, part cooling fan(s) and levelling sensor.

8 minutes ago, alan potts said:

I have had a problem with my mouse and it's been double clicking even when I only single click. I am wondering if it has done something unknown to me. Just stacked and tried a set of 13 images of Leo Triplet and that looks fine. I have to say my Flat don't look right, way too dark and it wasn't.

Alan

Hi Alan,

I bet the mouse issue gets frustrating. I was taking some flats the other day and I got a strange circle shape in the middle of the image and I do not know what was causing it. But I altered the position on the LED tracing pad with a sheet of A4 and ran the process again and everything was fine. I have found that when I use SharpCap and use some of its sliders it can alter the settings of the main imaging camera. With the beta versions of APT and N.I.N.A you can set them to set the gain and offset prior to imaging and that has helped. I once found I had different gain and offset settings to my dark library and APP certainly made the stacked image look rather wierd.

Grant

Just now, astroenthusiast said:

Yes, my lights look green. I'm also having a hard time with getting my flats correct. I'm using SharpCap, I'm wondering if that's is one of the issues, Lol!

I use the beta of APT or the latest nightly build of N.I.N.A and I found that when I ran SharpCap on my imaging camera I remember that I altered the brightness setting to see the image better and that really threw off my settings as it alters offset and gain. In APT and N.I.N.A. you can now make sure that the gain and offset are always sent to the camera prior to imaging which I have found really helps. I remember I used a gain of 111 on my ASI183MC and all my Darks were 111 and then one day I found that my gain had gone back to 100 and I was still using the 111 gain darks which caused some very strange results in APP.

17 hours ago, astroenthusiast said:

Sorry for the delayed response. I'm using Astropixel to process my images and Adobe Photoshop. I'm reviewing Pixinsight but all this software does get expensive.  My camera gains are high at times, anywhere from 200 to 350.  It's going to be a clear night, and I'm anxious to take out my ES ED165mm to capture some great images, the moon also is out tonight. I may try a duo band filter. The camera I'll use tonight is the ASI2600 MC Pro, color camera. I've tried using the Starlight Xpress 825 monochrome CCD camera and filter wheel but it's a bit of a learning curve for me.  Totally diffrent than a CMOS camera, I'm open to any suggestion on the CCD camera. Thank you!

I now use a camera now which has the same sensor as your ASI2600MC Pro camera after upgrading from my trusty ASI183MC. I only use my WO Zenithstar 61 with FLAT 61A at the moment but use the Optolong L-Enhance filter and use Astro Pixel Processor and PS only for my images and they are coming out great. I have found in the past with my ASI183MC if the darks have a different gain and offset as well as temperature then strange things will happen when I stack the lights in APP. Do your individual light frames look green?

I found when I got unusual results I took a look at the FITS headers and found that the gain and offset had changed between my dark and light frames and that causes all sorts of strange things to happen. One I took some replacement darks for the same settings everything was fine again. Maybe worth a check.

Welcome to SGL. I only started myself in December 2019 and am still learning but it is certainly an incredible feeling when you see images come out in post processing and know that you took them.

Here is hoping for clear skies!

Thanks Cornelius, must have missed that post when I was searching. I see TS show it should be in stock around March which is probably more realistic, so will have to be patient 😀

So with David Hinds closing it's doors who seemed to be the main uk distributor for Celestron who is going to be the distributor now? I know that the pandemic has caused issues worldwide but it would seem that many Celestron products are unavailable in most places so just wondered if any knows when production and supplies are going to start again?

I have been down this road and think that the best way is to have a Raspberry PI or Mini PC at the mount. Mount control should be done via Indi/Indigo or ASCOM depending on OS used. I would recommend direct connection for cameras as I found that via Indi/Indigo or ASCOM the cameras did not work as well as they do under a direct connection and trying to do run a focus loop over wifi was just terrible but much better via ethernet but still not as good as direct. This is why I ended up using an XCY30 MiniPC with Windows 10 and a RaspiOS under Virtualbox so I can use Indi/Indigo or ASCOM. This gives me the option of running the really great Windows apps such as Sharpcap but also the ability to run KStars and EKOS.