Astro_Nic

7 minutes ago, Cosmic Geoff said:

You need an ADC for good results, but you may find difficulty in getting it to work with a Newtonian.  You might also have trouble getting the camera to focus with a Newtonian not built for imaging, but a barlow might help here. 

80GB sounds a lot. If that's correct, how long do you think it will take your equipment to move this amount of data around, and to process it?

A gentle reminder that getting the right astro kit for the job, (e.g. a GoTo SCT) will enable you to:

1) let the hardware take care of tracking

2) let you hang any kit on the scope without worrying whether you will run out of focus travel

3) Allow you to get the planet on chip without too much trouble, potentially reducing chip size and camera cost.

4) Reduce data storage requirements and hence laptop cost.

5) Reduce size of video files to be processed

6) If you can't crop the videos after recording, recording with a small ROI will make it practical to archive your videos and re-process them months or years later.

7) Reduce time and labour required.

 

Now you've got me worried I'll spend all of this and not be able to focus and it will all be a waste!  Is there a way to find out prior to I spend a small fortune?

Thanks.  In terms of running the videos, do I keep the scope stable and let the planet drift across the view, rinse and repeat, or do I attempt to permanently keep the planet in the view? 

Thanks

Nic

15 hours ago, sorrimen said:

678 undoubtedly. The lower read noise in the 585 won’t come close to the difference between optimum sampling and significantly undersampling. Even if you struggle with 3200mm, the closer you are to optimum sampling the better.

Thanks for your advice.  Looks like a 678 and a 2x powermate  

What else do I need to get started?  Filters? ADC? any adapters to get it all fixed together?  Also need a laptop!  Costs mounting up....lol....plus buying a new car on Saturday!  Don't tell the 'boss' !

Tracking may come later, but trying to get this work for now.

I am going to 'build' a laptop, so I'll definitely get one with a 1TB SSD but will probably add at least another one and maybe add an 8TB external, so I'm not too bothered about file sizes.

It looks like the choices are the 678 with 2um pixel sizes - so 2 x 5 = f10 (FL 3,200).  With my f4.6 I would then need a 2x barlow (x2 televue powermate, so that I could also use it for visual).

The other choice would be the 585 with 2.9 um pixel size - so 2.9 x 5 = f14.5 (FL 4,800).  With my f4.6 that would mean a 3x barlow (no 3x powermate so would have to be the barlow - cheaper at least).

Which is better?  Do they work for under/over sampling?  Is there a calculator somewhere?

Thanks!  

wow this is complicated!  So putting a 678 into the FOV calculator on the FLO website with a 2x barlow shows a very large square and a small jupiter.  Using a 585 with a 4x barlow shows a smaller square and larger jupiter.....or is a 4x barlow too difficult for manual tracking?  Or am I looking at the wrong thing to decide?

1 hour ago, Cosmic Geoff said:

That should work, but try to find out what amount of data 5000 full-size frames represents with this camera, and what the maximum frame rate would be., before you invest £400 in it.  (With an ASI 224 or ASI462, 5000 frames of 320x240 px = about 350MB, and frame rate is about 250 frames/sec with short exposures of a few ms on bright planets). 

I guess 5,000 frames at 16.6mb a frame would be 83gb....that an issue?

Thanks.  The 662 does look appealing, but a lot of people have suggested the 585 to help keep the target on the sensor more easily.  Having not done this before, I don't know which is more important.

Cheers

Hi everyone

I'm keen to make a move into astrophotography, although I know my setup is not designed for that pursuit.  I have a manual Orion Optics VX14 1/10 dobsonian with Nexus DSC pro.  I'm aware that a dob isn't the best for photography, however, I got it for visual and that is where my passion is.  But I thought it would be good to take some planetary photos at the end of a session.

I have absolutely no idea what makes a good camera for my setup for planetary (and possibly some basic DSO if possible - globular clusters?).  It's a f4.6  FL1600 aperture 350mm, although with the Parracor it's f5.3 FL1,840 (parracor needed?).  I want a dedicated astro camera - ZWO:

- I assume I need a large sensor as it is manual to try to keep the image in view?  What is deemed to be large for this?

- What resolution/sized pixels would be best to get a good clear view?

- What other stats are important for planetary viewing with a dob? I see things such as well depth, noise, black etc - no idea what I am looking for!

- Was looking at the ASI662MC (2.9 um 1,920x1,080 5.6mm x 3.1mm) or the ASI678MC (2um 3,840 x 2,160 7.7mm x 4.3mm)- they give good close up views, but is the sensor too small?  Then there is the ASI585MC (2.9 um 3,840 x 2,160 11mm x 6.3mm)- nice large sensor and resolution but a smaller view......what do I need?

Any manual dob users out there who can offer some advice would be great.

ps, not interested in getting a dedicated photography rig - I realise that would be much better and that it won't be easy with a dob, but I have seen some great results with manual dobs so would like to give it a try.

Many thanks!

Nic

That's exactly how I saw saturn the other night - was really confused - basically 4 blobs in a star shape - no disk, no rings, nothing.  Quite annoying as I thought my 14 inch dob at high magnification would be able to see the rings.  Saturn was lowish in the sky and I did have to look past a street light, so I put it down to those issues, but I was seriously confused.  Some of the images I see on here with lesser equipment look amazing!  Scope seemed to be working ok.  Could see bands on Jupiter which was much lower in the sky and could see the ring nebula nicely, so don't think it was a scope issue.

Any help from the experts here would be a great help.

Thanks for all your help so far.  I can see and understand what needs to happen to the secondary mirror.

Whistlin Bob has very kindly offered to pop round next week and hopefully we can get it sorted together.

I sent the photo with the two circles highlighted that weren’t concentric to Orion optics and asked them to assist.  All they could say was that they don’t collimation that way and directed me to their guide.  Surely if the collimation cap and Cheshire show the secondary needs moving then it needs moving, regardless of your collimation method.  Not impressed.

Okay I've tried to get some more pics which might help....they might help you, they don't help me!

1-This is the view through the cap with coloured paper behind secondary

2 - View through cheshire / sight with coloured paper behind secondary

3 - View through focuser opening with mirror covered by white paper

4 - scope

Thanks

So really struggling with collimation….first view through collimation cap - makes sense and I understand it - I’ve also put card between primary and secondary and card behind secondary and the view looks good. Nice central, circular secondary.  The second pic is through a cheshire/sight tube.  I just don’t understand what I’m seeing and what is going on.  Can anyone help?  I’ve got some great collimation guides but my views bare no relationship to what I’m seeing! So the sight tube is massively offset from the bright Cheshire. There are two bright circles in the centre - one offset.  I can’t see all the primary as it is offset to the right. Looking down the focused/cap looks fine but no idea what’s going on here - it’s like the Cheshire is angled to the right.  Got the Cheshire well clamped in a Baader click lock.  The photos match what I am seeing. Thanks!

On 23/02/2022 at 22:00, Second Time Around said:

Just clip them onto a 12 volt battery.  I use Yuasa ones, either the hand size 7Ah ones that fit burglar alarms or for my short sessions the tiny 1.2 Ah size. Either fit on the rocker box of my 8 and 10 inch OOUK Dobs.

I suggest you buy 2 so that you always have a spare.  I've got 3 of the 1.2Ah size and 1 of the 7Ah size. (I've just given 4 of the latter to a fellow club member).  I rotate them, keeping 1 permanently on charge and use this one the next session.

 

Took your advice and got a couple of the Yuasa 7Ah batteries and connected it up tonight - I was surprised that the fan blew the air out of the tube, rather than blowing onto the mirror….is that correct or have they fitted my fan upside down?! 

thanks!

On 02/03/2022 at 17:36, ollypenrice said:

Please note that I'm not slagging them off. I simply suggested a line of research. If you'd like to hear about my own (and one of my customer's) experiences of after sales then it will have to be via PM.  All I have ever said publicly about this firm is that the ODK14 I used for a few years worked very well. I repeat that here.

Olly

Apologies, I wasn't suggesting you were.

1 hour ago, ollypenrice said:

For the bad news, Google Orion Optics UK customer service.

For the good news, look through the scope, not at it.  Such blemishes will have no effect on the view whatever.  If the figure of the mirror is as they say then the views will be excellent.

Olly

Well I did all my research before purchase and weighed up all the pros and cons, so I'm well aware of some issues people have had in the past.  However, having dealt with them now for a number of months I have found them perfectly fine.  They were quick to answer all my queries, they helped set up the scope how I wanted it, offered advice.  When I picked up the scope they were friendly and told me to get back to them with any problems and issues and they have agreed to give my scope another once over.  I am therefore completely happy with the customer service of Orion Optics.  So I don't know if these are historic issues or if some people have just been a bit unlucky, but I do sense a touch of cancel culture in respect of OO from some people......a number of people on another astronomy forum actively slagging them off even though they themselves have never dealt with them.

I prefer to judge people and businesses from my personal experiences rather than hearsay from the internet.  You'll always have issues highlighted online, but you never hear about the thousands of other customers who received the service they expected but didn't see the need to post as such.

All I need to work out is how to collimate this damn thing and why the cap and sight tube are so different!

Thanks all

Nic

The photos accurately reflect what I was seeing with my eyes.  The two views are very different.  Assuming the Cheshire/sight tube is correct, where do I start?! 
 

why are they so different? Maybe the issue is the plastic 2” to 1.25” adapter and I should wait for the baader to turn up.  

The photos accurately reflect what I was seeing with my eyes.  The two views are very different.  Assuming the Cheshire/sight tube is correct, where do I start?! 

On 26/02/2022 at 22:41, Spile said:

Do give my guide a try and see how you get on https://astro.catshill.com/collimation-guide/

Thanks for the guide….I attach my views - firstly through a collimation cap and second one through the site tube/Cheshire.

what on earth does it all mean?! Please go easy on me! Lol

thanks! 

Panicking about collimation now.  Really have zero idea what I'm doing!  Last night I centred the secondary adjusting the spider vanes.  But then I'm a bit lost.  I have a collimation cap and looking through it and things seem ok - or rather I can understand what I'm looking at, but I have the red cheshire/sight tube from FLO - and this shows a completely different view - the cross hairs are no where near where they should be - but it wobbles so much in the focuser that it flies around depending where you bend it - the OO has a plastic 1.25" adapter - I've just ordered a Baader 2" to 1.25" clicklock adapter to help with this.  But still no idea what I am supposed to do!

I will read the guide posted above.  If anyone else has any advice, that would help as well.  Or any local people would be most welcome to visit and assist! lol

Many thanks everyone!  Clear skies!

OK, so no idea how to collimate! What’s the best guide? I have a cap and a Cheshire eyepiece.

so the black spot is clearly seen through the cap - not surprising as still just looking at the mirror? Or more worrying?

secondly, I attach a back view of the mirror - every guide I’ve seen shows lock screws on the mirror - mine has none, even though there are clear instructions to only finger tighten - finger tighten what? Please see image.  Is this normal for OO or do I have an issue?

many thanks as always!

Nic

2 hours ago, Whistlin Bob said:

That's a mighty telescope to be starting with! I'm sure it will perform fantastically with or without those spots.

I noticed that you're in Burton. There's an Astronomy Group at Rosliston Forestry Centre- we have a mid month meeting which is all about practical astronomy, and especially helping people get kicked off with astronomy. If you bring your scope along we'd be more than happy to have a look at it and let you know if we think OO are being fair in their response, and also help you get started with it.

You can find out more details here https://www.roslistonastronomy.org.uk/

Hi, thanks for your reply.  Yes, I definitely need to join! I know nothing about how to use this beast!  I’d love some help.  All I know is that it’s a lot heavier than I was expecting! Lol

i still need to work out how to power the fan with crocodile clips! 
 

thanks

nic

Many thanks for your advice.  I've agreed with OO that I will use it for a few months and see if it is noticeable in real life and then I can pop in with it next time I am passing and they will take a look just to confirm nothing is wrong.  I certainly don't want to take it apart or try to blow air on the mirror!  But I am the sort of person who will think about that spot everytime I get the scope out!

On another point - the 12v DC fan at the bottom comes with two crocodile clips!  What on earth do I attach those to?  Or is there an alternative cable I can buy to plug into a 12v power supply?  Thanks

Am looking forward to first light with my first ever telescope!

Hi everyone

Hopefully you can offer your advice.  I have finally taken delivery of my 14" Orion Optics (UK) dob.  Looks great and I got the 1/10PV mirror and zygo report.  However, I have a couple of issues with the primary mirror that I was hoping you could advise on:

• There are two jet black spots on the mirror - one a few mm in diameter - please see pic.  This is clearly visible looking down the tube - I can't get close to the mirror to determine what it is and am reluctant to start dismantling anything as am a complete telescope novice.  I've tried using a hairdryer down the tube incase it's something that will come off - it doesn't move;
• When a torch is shone down, the mirror has small dots and dashes on the surface - nothing significant, just very faint - I assumed it would be absolutely crystal clear.

I have gone back to OO and they have said that the mirror has passed all QC and that there are no problems and the mirror is significantly better quality than I would get elsewhere.  I do not doubt this, but there are two black spots on the mirror!  This can't be right can it?  I assume the dots/dashes are not scratches but related to the coating process in someway and I am less bothered about that.  But the black spots?  Many thanks for any advice you can give.

The zygo report shows Strehl of 0.992 and 1/10 PV and very low astigmatism.

Nic

Think I've decided to go the route of the Orion ST80 as my extra finder.  Please can someone recommend a suitable eyepiece and right angled amici prism for this setup?  I was thinking an ES68 24mm to give 16.7x mag.  The existing finder gives 8x (8x50)....the higher mag should help in the not brilliant skies.  Although shame the 27mm is 2 inch.

I know nothing about right angled amici prisms.

Thanks

Nic