Icesheet

Thanks for the input @Davey-T . Do you have the Star71 too? Any preference for one over the other?

Great, hopefully he gets the chance to chip in 👍🏻

It is a bit of click bait isn’t it 😂 The AZ GTi might struggle with a refractor that size! Will edit the title 👍🏻

Thanks, the Star71 was one of my preferred options. Have you used it?

Looking for some recommendations for a compact apo in the 250-350mm focal range. I had been intending to get a WO RedCat but there seems to be mixed reviews. Similarly the 71mm quad APO (WO/ Meade/ TS) seem to get very little or mixed reviews. I would prefer to not have to deal with focal reducers/ flatteners but will for the right scope of course. Plan is to mount it on an AZ GTi and image with an ASI1600mm. Any first hand experience with any of the above or anything you can recommend would be appreciated! Edit: No set budget but the 71mm quad at ~£1200 is probably my top end

Thanks folks!

I’ve always wanted to attempt narrowband and in particular the Hubble palette. This is my effort on the heart and soul nebula’s with the Samyang 135 and ASI1600mm. 90x120 Ha 30x120 Sii 30x120 Oiii +calibration frames. I have to be honest, I’m not really sure how I got to this ‘final’ image as there was a lot of fiddling and googling going on! Looking for some honest feedback. My stars aren’t the greatest, mainly due to including an hours worth of Ha which wasn’t framed properly and had poor stars. Actually my corners (and focus) never seem to be great with my Samyang copy, so this is also cropped down. May have overdone it a bit with saturation and contrast and the background sky may be a bit too bluish? Will keep working at it and hopefully use any feedback from here! Edit to add calibrated and stacked Ha, Sii and Oiii channels. Alwys interested to see what people can do with my data. AutosaveHA.tif AutosaveOiii.tif AutosaveSii.tif

I have received some good feedback from the Phd2 group on this. It seems I haven’t set up things properly and that may be exaggerating the backlash issues. Just need to wait for another clear night to see!

Seems to me the HEQ5 would be the best choice for you as it would be a seamless transition. I would get a belt modded one if you do. I have to say personally, I have a draw towards the iOptron offerings just now. Part of me wishes I had gone with my instinct as I now seem to have potential issues with the EQ6-R I just bought

I haven't guided for some time now but I was recently out guiding for the first time with my new EQ6-R. The first night I used an Orion mini guider with Altair GPCAM2 and the guiding I was averaging was 1.7"RMS. I spent most of the night trying to work out why as I had routinely guided sub 1"RMS with this on my old HEQ5. In the end up I only managed 40mins imaging time. However, the stars looked good albeit probably bloated. I had read about the PPEC function on the EQ6-R so the next night I decided to run AutoPEC on EQMOD to generate a PEC curve and load that to the mount so I could use the PPEC function and hopefully improve my guiding. I also used my main imaging set up of Esprit 100ED and ZWO ASI1600mm to give me the highest resolution I could achieve at 1.43"/px. I have loaded the PHD2 graph and log below. As you can see the first hour or so was used to record AutoPEC on EQMOD. This averaged 1.22"RMS error. When I switched to PPEC this dropped down to 1.02"RMS which although better still left me disappointed given that my HEQ5 gave better results and that was just a push the button and go job. I then ran the guiding assistant which I have never used before. Screenshots attached from that below. The main take home from it is that my mount seems to have excessive DEC backlash of over 7sec! I have to admit that I am no expert with this so I'm hoping someone with experience can look into this and advise. Is this backlash the main source of my poor guiding or is there anything else going on here? Can this be solved by optimising guiding parameters and perhaps balancing my set up better to counter it or is this backlash severe enough that it requires some mechanical attention? I'm really reluctant to get the tools out for such a new mount. As always any help or advice appreciated! Edit to add: •Not entirely sure what seeing was but at least average probably better • I believe there was a focus issue with the GPCAM the first night so that probably contributed to the poorer guiding the first night PHD2_GuideLog_2019-11-11_011955.txt

You could always go for the CEM25p at £725. Still guaranteed +/-10 arc sec or less. That should be plenty good for unguided exposures at 135mm. Plus you have your guiding set up anyway 👍🏻.

That looks like a fantastic little set up! How do you find the CEM25 EC? It’s been interesting me for a while as a set up for my ASI1600 and Samyang. Gets tiresome pulling out the EQ6 for that.

Great image 👍🏻 Im curious how you focused the lens with the ZWO EAF?

I think most people looking for an astro camera at that price point would normally be a fairly serious astrophotographer and be looking at the CMOS/ CCD offerings. I would have thought there would be more interest in a moderately priced astro APS-C sensor camera for beginners/ intermediates. Having said that they have periodically released Da’s and Nikon had the 810a. Considering the mark up on the regular model no doubt they’ll make money from the ones they do sell.

Officially released now https://www.google.co.uk/amp/s/www.dpreview.com/news/4797098001/canon-unveils-the-eos-ra-a-full-frame-mirrorless-astrophotography-camera.amp

As far as I’m aware you can’t purchase a copy outright anymore. You used to be able to buy the old version but it’s not available anymore at least through official channels. You might be able to find a version somewhere but you’ll still probably pay around two years worth of subscription and not get any support if there are any issues. If you really don’t want to pay a subscription you could consider PixInsight or one of the free processing packages Edit: @Buzzard75 beat me to the post button but as he says basically!

Well I would treat the narrowband filters as a bonus available to you if you wanted later If you were to go down the CPC1100 route, which is a huge step for even an experienced imager, I would upgrade your mount first for sure. Camera wise I would say the ASI071, particularly with hyperstar. If you really want my honest opinion. Scrap the idea of a CPC1100 and get a short focal length refractor and any of the above cameras to get some good experience in widefield imaging then step up to longer focal lengths if thats what you want. I’m not saying what you’re planning can’t be done but it’s certainly not the easy route and there will likely be a lot of hair pulling getting there!

I don't really want to influence you re mono/ colour except to say that if you plan to do narrowband I would go mono. Apparently it can be done with OSC but not straight forward. I checked the cameras you mentioned above plus the another popular ZWO the ASI 1600mm against your scope (SW 200P right?). Here's a snap from astronomy tools with M45 as an example for FOV. With all these cameras you will have a resolution <1"/px. My first instinct is that will ask a lot of your mount and tracking at 1000mm focal length. With that being said, if you can spare the extra cash, I think I would go for the ASI071. Gives you the best FOV and is also the best in terms of resolution. Even more so if you are at a dark site. By the way regarding perice the ASI1600mm it is available with mini EFW and LRGB filters for the same price as the ASI071 at the moment

There are a plethora of cameras available these days so I’ll not recommend any one as it would depend on a few things. First thing I would decide is colour or mono. You could read until the end of time on here what is best. Just pick what you think suits your likely imaging preferences Then you really are better pairing a camera with your existing scope (and any you plan for the near future). What you are really looking for is a resolution that will suit your set up and likely seeing conditions. I recommend going to Astronomy Tools.net and using the CCD suitability tab and plug in different camera/ telescope set ups to see. If you do that you will have narrowed down the options quite a bit. Good luck!

Regarding the argument of always having ‘complete’ data regardless of integration time with OSC. Why can’t you have this with Mono and filter wheel too (at least if you have a motorised one using a sequencer)? I know there is the argument that you should focus between each filter but I’ve also read that it’s only really critical for your Lum to be in focus for the detail. So if time weather/ time is an issue why not set up a sequence of exposures that just rotate through the filters? Sure you won’t have critically focussed RGB but then it’s a compromise you can surely accept for a ‘complete’ image? I mean OSC must be making that compromise in every exposure anyway?

The seller is in the UK. You should check out the classified forum on Cloudy Nights if you are a member there.

Let’s be fair here he says nothing of the sorts. He actually states the point of the video was to demonstrate how PixInsight utilises multiple cores and threading to speed up processing time (which was the point of the OP), not that you need that Mac to do it. We we are all free to choose the hardware to do the job as is he. I’ve actually found him to be the most knowledgeable of the YouTube astrophotographers. Worth a follow.

Good choice 👍🏻 The HEQ5 is a tried and tested mount with good support on here. You’ll also be able to put a decent sized refractor or newt on it if you decide to upgrade your 72ED in the future too.

Looks like Dylan O’Donnell recently made a similar upgrade decision as you.

This is what I was getting at, although I didn’t want to quote specs I had been given as it was not my place to do so. I’m not an engineer but I can’t see why the ‘upgrades’ couldn’t have been added to the existing CEM40. Also, looking at the expected retail price there’s every chance it will be squeezed by the cheaper CEM40 offering and the competitively priced CEM60.