Midnight_lightning

That's a difficult question to answer, it depends on how keen you are on the hobby, how far you expect to progress and how much money you are willing to put into it over time. I started with an HEQ5 (Excellent mount), NIkon D750 (unmodded) + Backyard Nikon control. Then added an Esprit 80 (Excellent scope), Guiding (Finder Scope), a cooled CCD (SX814), 5 position EFW, Filters, Guiding OAG and SGPro/PHD2 etc. 

I have just upgraded scope, mount, EFW, filters again and am now designing an observatory. 

I'm hooked on the hobby and whilst its not cheap at any level it has become the main drain on my hobby wallet by far - so beware! 

I suggest consider where you think you might go, for what its worth these are my regrets, easy with hindsight hard to predict without it:

• Buying an HEQ5 - Its a fantastic mount if you want to use scopes like the Esprit 80 and will give you 20 minute NB exposures (guided) no problem and I would suggest this mount as a minimum starting point! But if you may want to get a bigger scope later, as I did, you will need a bigger mount. The EQ6 R Pro may be out of your price range but take a look. I predict once you get a mount you will start to look at telescopes.
• Buying a 5 position EFW - Having to swap filters out to switch between LRGB and NB is a pain - yes you can do it but it takes time and risks getting dust into the EFW.  I wish I bought 7 position from the outset. 
• Camera - I already had a Nikon D750 but a cooled camera is so much better I wouldn't buy a DSLR or mod one purely for Astro. My SX814 is an amazing camera, low noise and high resolution and my images improved significantly but there are much cheaper cooled options. That's not to say you cant take great images with a DSLR, whilst not technically my best image one of my favourites to this day was taken with my unmodded Nikon ( https://www.astrobin.com/0wtqko/?nc=user ). I bought a cooled mono camera early on and am glad I did the reduced noise makes a huge difference- had I got colour I would have soon replaced it with mono.

It's an expensive hobby and hard if you have a tight budget so really think about where you are going with it - buying second hand can help and you can use the time between upgrades to save up and gain experience. I suggest you focus on getting the best mount you can afford, everything else depends on the mount, also having goto is amazing and saves a lot of valuable imaging time - If you want to progress in the hobby I suggest a goto is vital. If you get into using SGPro or similar the goto allows you to image the same subject over several nights - you just tell the software where you were imaging last night and it will plate solve and get you within a few pixels of where you were and you continue imaging.  You can then stack lots of subs, reduce noise and get vastly improved images.

Lots of options, unknowns and steep learning curves so hard to be specific but I would probably try and start with at least an HEQ5 and perhaps look to get a second hand one if necessary. It depends how hooked you are, if you are keen and going to do this for at least a few years I expect you will go down a path similar to this adding items:

• Mount - using unmodded DSLR and BackYard Canon (But I would look at NINA/SGPro from the outset)
• Use DSS for stacking (Free) and something like Star Tools for processing (cheap and easy to use - you will have enough learning to do on other things for now)
• Telescope - short FL - something like Esprit 80 / 400 (Don't buy a long FL scope to start with they demand too much of the mount and guiding skills which come over time.) Use with DSLR to start with.
• CCD/CMOS Cooled camera + EFW and LRGB filters (Colour is ok but look at mono - its more efficient/flexible)  - there are plenty of targets that fit a small chip so you can keep costs down. 
• Imaging software (SGPro/NINA etc) - if you don't have software control you will now star to need it.
• Guiding - Guide camera + use the finder scope that probably came with the scope.  PHD2 software
• Autofocuser - not vital but so much easier - nice to sit indoors whilst imaging  
• Polar Alignment support (Polemaster or SharpCap etc) - Best non essential item I bought - I never have to look though a polar scope again - all done in a few minutes
• Ha OIII SII filters (why you bought a 7 position wheel for LRGB earlier)
• PixInsight for processing images and stacking
• OAG - using same guide camera
• Bigger mount/Scope/full frame cooled camera/observatory

Lots of choice in hardware and software, I've mentioned what I use but lots of alternatives. You will ultimately want to use PixInsight but personally I think its a big learning curve with everything else when you are starting and Star Tools is very good for LRGB processing, less so with NB. (I can produce stunning LRBG images in Star Tools in 20 minutes - takes me all day to do the same in PI - but eventually it becomes limiting)

So, have a plan, short and medium term, do one thing at a time, lots a baby steps because you will change your plan as you progress and gain experience. 

Hope this helps, there are few right or wrong answers, good luck with whatever you do!

10 hours ago, Adam J said:

There is a very new ASI2400mc pro coming out not to be confused with the smaller ASI2600mc Pro, at that focal length I would go with the 2400 as its even more sensitive.

*****************Forget all that just seen this is about the mono version, my mistake.

I've read somewhere tat there is a mono version of the ASI2400MC due out later this year - maybe October but who knows with Covid. I have it on my list of options.

Thanks, that was what I thought but then saw a Youtube video that said the opposite.

I'm struggling with spacing and have read lots of conflicting information about how to interpret results. 

This image has elongated stars in the corner - all pointing to the centre. 

I believe this may mean the sensor is too close or too far from the reducer - can anyone tell which is it before I spend another night trying to get it right?

https://www.dropbox.com/s/1a9gk7niarl9oqb/CFF RR 686 2-0mm Spacing__1x1_30sec_frame3-1.jpg?dl=0 

3 hours ago, vlaiv said:

I started this post believing that there would be significant difference between 3nm and 7nm on fast optics, but it turns out for regular F/ratios that we use in imaging, 3nm is just fine.

Really helpful, many thanks vlaiv

12 hours ago, Jkulin said:

Hmm, I own 2" Unmounted 3nm Chromas which are certified at 3nm so not sure where you heard that?

Someone posted it above, I should have checked it was accurate before propagating it - apologies

14 hours ago, Ken82 said:

Here is a halo comparison I did earlier. 

That's really useful Ken. The price of these things is crazy but having spent thousands on a mount, cameras, telescope and goodness knows how much time learning the trade I'm not going to put up with halo's when I dont need to

6 hours ago, Ken82 said:

I also made the same decision but based more on my light pollution. 
 

I believe the chroma guys are on record as saying “in most circumstances the 5nm are the right choice” so this made me really think about it. 
 

 

I'm tempted to say the Chroma guys would say that given they don't make a 3nm but maybe that's a bit unfair - perhaps that's why they dont make one. 

That said for the relatively small increase in price it would be good to be able to image when there is a moon - probably double the number of imaging nights I get a year.

59 minutes ago, DaveS said:

For 135 format you will need 50mm unmounted filters as 2" ones could well vignette badly.

You will definitely need a more powerful computer to handle those files in any sensible time, I would be spec'ing a tower with a Ryzen 12 core and at least 32 gig ram, plus a few TB of SSD or better M2 storage.

The i3 laptop is just running the imaging, I have a fairly good spec desktop rebuilt a few months ago - Ryzen 3700X, 32GB 3600mhz Ram, 500GB M2 with dedicated lane. I think 8 core rather than 12. Also has a good GPU so hoping APP and PI will make use of this before too long.  Actually I would like to push this PC a bit, I haven't seen it using more than 11GB Ram to date and its rare to see CPU max out.

Having upgraded my telescope to a longer refractor (135mm FL 686/915mm) I am looking to now upgrade my cooled camera to larger sensor.  I would like to go full frame but may wait until October  to see how much the new APC-S cameras are. 

In terms of full frame (circa 60mp) I have tried to put together some pros and cons and would be grateful for your thoughts on these and also any experience you have using cameras like the ASI6200MM and QHY600. 

Pro's

1. Large FOV, less need for Mosaic's so faster imaging
2. Produce widefield images with option to crop - flexible framing for small and large targets
3. Wider field will make it easier to remove LP gradients where the frame would have been full of nebulosity with a smaller sensor.
4. Large targets like Andromeda wouldn't fit on a smaller sensor.
5. New cameras are 16 bit.
6. Gain (not sure about this, afaik my SX814 has fixed gain - could increasing the gain on a CMOS reduce exposure time?)

Con's

1. Expensive
2. Requires a good Corrector/Reducer.
3. Adjustment for tilt more demanding.
4. Large amount of data to store and process (how big an issue is processing?). Five times the data I currently hold - will need new HDD's for storage and multiple backups.
5. Potentially greater LP gradients that will be more difficult to remove than with a smaller sensor
6. Testing my scope with a full frame D750 shows some Vignetting.
7. Is CMOS as good as CCD for image quality - my SX814 is extremely good in my view? 
8. My Astro imaging laptop is very low spec (i3) - not sure it will cope with downloading 60mb files{?}.
9. Large EFW - extra weight could add to tilt.
10. Large EFW - size could mean it hits tripod legs (But QHY cameras have camera rotator so may not be an issue - the Rotator is reason enough by itself for me to to buy a new camera!!!)

An APC-S camera would be half the price as I could use my existing EFW with 36mm filters - also cheaper than 2". But I think I would be kicking myself when I couldnt frame some of the larger targets.

I haven't started to look at technical stuff (well depth, QE, Noise etc) yet - its a whole new learning curve for me.

Any thoughts/guidance welcome.

I am going to upgrade my camera (separate post) and will need larger filters. Scope 135mm (FL 686mm/915mm depending on Reducer/Flattener)

I currently use a Baader NB set of 7nm filters (Ha OIII SII) but thinking I may splash out on some Astrodon or Chroma filters and wondering about the merits of 3nm - especially for OIII. 

We have Bortle 4 skies here but the rate of building in the area means this will deteriorate.

I have seen images taken with 3nm filters and they do seem to have more depth/contrast and particularly with OIII handle large bright stars well.

But presumably, if they are letting less light through, I will need longer exposures (?)

I'm out of my depth knowledge wise when it comes to filters so would be grateful for any  thoughts about the relative merits and disadvantages of the various bandwidths.

On 20/06/2013 at 17:12, IanL said:

So I image with a Canon EOS 500D with pixels that are 4.7µm square and a Skywatcher Evostar 80ED and 0.85x Reducer with an effective focal length of 510mm:

(4.7µm / 510mm) x 206.3 = 1.9 arcseconds per pixel

I guide with a QHY5 with pixels that are 5.2µm square and an Orion ST80 with an effective focal length of 400mm:

(5.6µm / 400mm) x 206.3 = 2.67 arcseconds per pixel

If you don’t feel like doing the maths, use my Imaging Toolbox to do the hard work for you. The upshot is that I my imaging resolution is about one and a half times my guiding resolution (2.67 / 1.9 = 1.41). That is well within the 4 x rule we established above.

Excellent article. 

You say above that your Imaging Resolution is 1.5 times guiding resolution but your guiding resolution is actually higher than your imaging resolution, so I would have said your imaging resolution is 0.7 times that of your guiding resolution.

I don't mean to be pedantic but I am struggling to get my head around the whole topic of PA and Guiding and I don't know whether this is important. For example does the imaging scale just need to be within 4x the guiding scale, either way, or does the imaging scale always have to be less than the guiding scale AND by no more than four times?

Thanks

All software latest versions. Oddly I have been running PI today without any issues so far - must be something else conflicting with it.

9 minutes ago, Dr_Ju_ju said:

Version of JavaScript ??  Post the image & I'll see if I can process it, as it may be the image is at fault ?? 

I dont know anything about JS and haven't specifically downloaded it, I assume it was installed with PI? How do I check version?

The SubFrameSelector crashes before it opens so I haven't actually loaded any data to PI before it crashes. I have loaded several different sets of data to Blink and it crashes with each. I should add that I am trying to reprocess data that I already processed a couple of months ago. 

I suspect the issue is related to the new hardware, my old PC ran PI perfectly and I restored the OS from old PC to new. I did have some issues initially getting drivers installed for the new hardware so maybe its a driver issue - although nothing showing as odd in Device Manager.

I recently built a new PC specifically to speed up PI and am having problems with it crashing in PI - everything else I use it for works perfectly. The system is based on Ryzen 7 3700X, 32GB 3600 RAM, ASUS TUF X570 MB running Windows 10.

I spent the last two days trying to process an image in PI and had the following issues.

SubFrameSelector more often than not wouldn't run giving error:

"run --execute-mode=auto "C:/Program Files/PixInsight/src/scripts/WeightedBatchPreprocessing/WeightedBatchPreprocessing.js"
Processing script file: C:/Program Files/PixInsight/src/scripts/WeightedBatchPreprocessing/WeightedBatchPreprocessing.js
*** Invalid block position: attachment:24576:97284096 (line=4 offset=208)
*** Error: The XSIF file contains no readable images.
*** Error [222]: C:/Program Files/PixInsight/src/scripts/WeightedBatchPreprocessing/WeightedBatchPreprocessing-engine.js, line 879: TypeError: info is null"

Blink always runs but then crashes in use - usually when I run the top STF button within Blink. I get this message and also various other messages referring to Address errors:

"PCL Win32 System Exception " at address 00007FFBC2AFAA09 with the exception code C0000005 Access violation: Invalid Memory Read Option at address"

Things I have tried:

Reinstall PI - done twice including manually uninstalling the bits the PI Uninstall leaves behind.
CHKDSC - No Errors
SFC /SCANNOW - No Errors
Upgrade GPU Drivers to latest version.
Memory Diagnostics - Basic and Intermediate test No Errors. Advanced test still running - 12 hours so far and only 60% complete.
Storage - 😄 90GB available. 😧 200GB available.
Posted on PI Forums yesterday - no response as yet. Juan did mention he though it was data corruption but that was it - and given its intermittent nature I cant see its a data issue.
 

The PCL Win32 error has been reported here back in 2015 but no details that I can see for what was causing it.

It's driving me mad now, can anyone suggest a way forwards?

2 hours ago, apophisOAS said:

EQ6R-r pRO  Capacity 20 KG

Ah, ok, when I saw 120 ED I was expecting it to be 10kg by itself

11 hours ago, apophisOAS said:

I have an EQ6-R Pro and its handles a Skywatcher 120 ED and an Altair astro 66ED-r plus 2 cameras plus Eagle3 s Control unit plus Guidescope.

That sounds impressive - any idea how much it all weighs?

6 hours ago, tomato said:

integration time racking up on every session

20 hours ago, AngryDonkey said:

If you are thinking about a dual scope setup then I would definitely recommend giving Voyager a try.

Thanks, will certainly take a look at this.

11 minutes ago, Laurin Dave said:

You could use the EQ5/ED80 for NB or RGB to add to LRGB or L through the 120 

Interesting. I have heard of syndicate imaging where lots of people pool there data from different sources. I know nothing about it but it makes me think I could piggy back my 80 on a 120 - maybe get away with EQ6R. No doubt there are draw backs with using different captures but something else to consider. Wouldn't the 120 have better resolution - so use that for Lum/NB and use the 80 for RGB?

28 minutes ago, Laurin Dave said:

I run a dual scope system ..  Esprit 150 with SX46 as the master and a piggybacked  Esprit 100 with an ASI1600 as the slave..  controlled by separate instances of SGPro, works like magic. Esprit 100 has slightly bigger fov..  I aligned by shimming the dovetail bars rather than going side by side.  the SX46 runs 10 or 20 minute (RGB or Lum/Ha) subs the ASI1600 2 or 5 min (RGB or NB) .. I dither every two subs on the master scope and use an OAG so lose subs when focusing as well as when dithering..   but my efficiency on the Esprit 100 in terms of good subs (ie no trailing) is in excess of 85% of that of the Esprit150 (even when both are doing Ha), partly its the mount (a Mesu) and partly its because of the ASI1600 sub length being short..  If instead I was running a second CCD with 10 or 20 min exposures and had synchronised dithering I doubt the overall efficiency would be much higher..  When I started with dual scopes I didn't dither as I didn't want to lose subs but I gave it a go and was pleasantly surprised..   so it can be done, depending on equipment  - serendipity not design!

To the OPs original question though I would think that a dual  Esprit120 system would require an EQ8 class mount as a minimum, they would also need to investigate a means of alignment..  an Esprit120 plus cameras etc will  be c 12kg so above the JTD capacity of 9kg

That's interesting, so if I understand correctly I could run my 20 minute NB on the guiding OAG/Scope and the 5 minute RGB on the tandem scope - and just accept that only 3 of 4 RGB's will be usable - still not a bad return.

Yes, I haven't looked at weight issues yet but will also be buying another mount - was anticipating an EQ6R-Pro for a single scope but two might be pushing it.

Just now, RayD said:

Dithering is an issue because if one camera is capturing when the mount dithers, it will ruin the sub as it will have trails.  Big deal with Ha particularly where you may be doing long subs.

Ah, ok yes, I was assuming both cameras would be running in sync but thinking about it that's more difficult than it sounds. 

37 minutes ago, tooth_dr said:

I use two copies of SGPro at the same time to run a dual rig. The second copy I just connect EFW and CCD. The first copy does all the mount control.

It means you can’t dither. For dual synchronised dithering I have used APT. It works perfectly. I switched to SGPro for the mosaic wizard but could see myself switching back.

I have two Atik EFWs attached. When I go to connect it asks for the serial number so i always connect to the right one.

The biggest issue will be hardware - getting them lined up and eliminating flexure. But if you get it sorted then a dual rig is amazing. I captured 10 hours of Ha data a few night ago, despite there only being 5 hours of darkness 👍🏼

Like everything else in this hobby like there is an investment in time and knowledge but that just makes the rewards even sweeter  Our weather is getting so poor here that doubling up on imaging time is worth a lot.

I don't understand why you can't dither though - unless your two scopes are aligned to the exact pixel. I'm probably missing something but if the SGPro controlling the mount does a dither and the two scopes are a few pixels out of alignment isn't it ok - the images from both scopes will all have a slightly different position on the sensor? 

I'm still agonising about which new telescope to purchase and have extended my budget several times - at least in terms of the scopes I am considering.

Now looking at 120mm - 130mm, the latter with a 0.75 reducer gives FL 585 at F4.5 which is quite attractive. 

Anyway, the reason for the post is that having extended my budget to consider some very expensive scopes I am now in the position that I could get two Esprit 120's and have a dual rig for a similar price. 

Just wondered what additional problems dual rigs pose? 

For example I use SGPro which would control the mount as usual but could it also control both FW's and Camera's (assuming twin set ups) or would I need another copy of SGPro and possibly a seperate laptop?

10 minutes ago, gorann said:

But then, what happens to the weight balance after a meridean flip?

I balance first then add a small weight to the east (Large Bulldog clip on the CW shaft or scope - with a piece of lead fishing weight attached).

After a flip I go outside and move the bulldog clip back to the east.