jacko61

This ^^.  It's a bl**dy expensive mount and should be perfect straight out of the box.

graeme

Are you using a CMOS camera?  If so then my preferred method is lights, darks, flats and dark flats as I've read that CMOS cameras should use flats / dark flats instead of Bias.  However, having just read your profile, The Bias frames you take with a DSLR replace the dark flats.  no requirement to take both types. 

Graeme 

Lovely image. How do you get your stars so sharp?  Mine always seem to bloat. 

Graeme

3 hours ago, Sypha said:

Thanks. Should I get a another extension tube to bring me closer to the back focus distance?

It sounds to me like you have the back focus (i.e. the distance from the back of the reducer to the chip) about right (and remember, this is just to ensure stars are sharp across the whole field.  @Elp has it right when he says you should rack your focuser in and out using the knobs the full distance to find where your scope focuses on stars.  Ignoring backfocus, if the scope is not close to focus then the stars won't show up.  What are you using to capture your images?  Programs such as astro photography tool allow you to display the live feed from your camera although the DSO option in ASI studio can work well. 

Graeme 

here's Monday night's efforts on the horsehead and flame nebulae. First decent night here since mid november so despite having a permanent set up I took quite a while to polar align and calibrate my guiding in PHD2.  The first sub I took was awful - hazy and distorted. After some investigation and stripping down I found condensation BETWEEN the two lenses in the Flat 73A which took some effort to clear (held it near the shed heater and then wrapped a dew strap around it).  As a result I only managed 2 and a 1/2 hours of 3 minute subs but I'm reasonably happy. 

WO ZS73 plus Flattener,  ZWO ASI2600MC pro,  Skywatcher EQ8r pro.  50 x 180 second subs captured and processed in APT, PHD2, DSS, STARTOOLS, STARNET and GIMP.  

Graeme

You're talking about two different 'flats' here.  Sypha has the flat 61R which has a back focus of 56mm so only needs 1mm adding to the adjuster if used with the standard ZWO extensions. Which filter drawer do you have for 18mm thickness?  My zwo 2" filter drawer is 21mm.

Graeme

8 minutes ago, Elp said:

I've never used an eq6, but my azgti requires an eqdir usb to rj12 cable (usb into asiair, rj12 into azgti), my gem28, the hand controller of the mount plugs into the asiair via usb. I assume your EQ mod cable is an RJ type one too?

Later EQ6 and EQ8 mounts have a usb 2 connector so an EQDIR cable is no longer required. 

Graeme

I'd go with your original gut feeling and get the 2600Mc pro.  I did    After using the 533mc pro for a while I decided I didn't like the square format at all - it made framing large nebulae and galaxies such as M31 very difficult. The 2600 has so much more real estate I can fit almost anything in the frame and there's always the option to crop.  The oil on the sensor issue seems to have been well and truly sorted so if you buy new you shouldn't have that to worry about.  One thing that amazes me is how the camera just works with no drama.  I can image one night, pull the roof back over leaving everything covered in frost then the next night it'll just work again despite having been covered in moisture all day.  It has a built in tilt plate and a built in dew heater for the chip and in UK versions, the chip protector has a built in IR cut filter so that's one less piece of dust covered glass you have to put in the image path. 

The only issue (if you can call it that) is the file size.  Each sub is 50Mb so you'd better have plenty of storage.  I've started moving all my subs to an external drive the day after imaging so my laptop doesn't clog up. Otherwise, it's a great camera that I'll probably stick with as long as I keep imaging.

Graeme

Are the two 'empty' holes threaded?  If so you can use them.  You can also use the hole left when you remove the focus stop screw as, not only is it redundant, it also gets in the way of the EAF bracket.

Graeme

Usual questions - are you sure you have your coordinates and date/time set correctly? Date especially throws a lot of people when they first get a computerised mount as it has to be entered in USA format i.e. MM/DD/YY.

The other thing to consider is that it's the mount you're polar aligning, not the telescope so if the mount is at it's 'home' position and you polar align through the main scope your mount will be off.  

Of course you may know all this and there'll be something up with the mount.  

Graeme

On 15/12/2022 at 13:23, wesdon1 said:

Hi, and thank you for comments. basically i am a beginner imager, only having a few nights imaging so far. I am currently still struggling to learn basic DSLR astro imaging, using no PHD2 guiding, and only using hand controller for locating and tracking/imaging. My tracking is pretty bad, for obvious reasons, so my subs are no longer than 30 seconds each. Now you have a bit of context, here's the main issue - Although I have tried to take great care to avoid the cable snagging again, when one is trying remember 100 different things outside in freezing cold weather, just to get some data, I sometimes forget about the snagging issue, and the most recent occurrence, I was seconds away from having another snapped cable through snagging. maybe I need to re-evaluate my imaging routine, maybe even write out a "to-do" list beforehand, so I know I won't forget to check cables are free and not catching/snagging? I do strongly feel though, that the design is pretty poor? But i'm a novice, so I could well be mistaken? 

Wes.

Once you start guiding, cable routing and avoiding snags will be your no 1 priority.

Graeme

Thanks for the update Steve. fixing the opener to the outside of the roof is so blindingly obvious it hadn't crossed my mind (which is why I've been struggling to figure it out - doh! ).  I stand in awe of your programming skills - I'm happy right now to go out to the shed to open it up and get everything set up for imaging.  I tend to either stay in the warm room or keep an eye on the weather / clouds out of the window if I come into the house so automating anything is a long way off (I'm still struggling with meridian flips so got quite a surprise this morning when my EQ8r flipped itself whilst imaging M42 - I didn't tell it to although I had previously set limits in EQmod. 

One last question if I may?  Right now I have a simple wooden rail with raised edges and 4 casters either side to roll the roof off.  Unfortunately there's quite a bit of sideways movement so I was wondering what you have your roof mounted on?  I'm looking at a V rail with V wheels but welcome any suggestions

Graeme

Hi Steve. 

Could you post a couple of photos of how you've arranged the gate opener on the shed and the roof please?  I've been thinking of motorising my roof as it's very heavy but haven't got a clue how at the mo.

cheers

Graeme

Monday night up here was as cold as  - well below -8. However, there was a very high haze across the entire view not far from lanark. I imaged the pleiades but the haze has affected all my subs and lost a fair but of nebulosity detail.  On the plus side, the camera cooled to -15 in no time at all   Tonight looks to be clear and the moon is further out of the way so I'm hopeful for a better session.

Graeme

In addition to Geoff's comment ' First of all, forget about 'back focus'.  It is largely irrelevant when imaging a planet or other object of small angular size, and is relevant for deep-space imaging with large-sensor cameras. ',  It's worth understanding that Back focus is not a function of the camera and ZWO should be shot for their insistence on stating 55mm.  Back focus is a function of the optics which in many case 'can' be 55mm from the last optical part of the scope e.g. the threads on the visual back of an SCT but is often not 55mm.  The back focus of my C8 sct for example is 105mm from the visual back and is also 105mm from the threads of the 6.3 reducer if I fit that for wide field imaging.  Another example - the back focus for my Zenithstar 73 with a flattener is 66.4mm and with a reducer is 56.6mm.  In fact, of all my scope setups, the only one expecting 55mm is the altair 150edf fitted with a reducer (with a flattener it's 91.5mm).   

On the subject of focussing, Geoff's advice is spot on and I'll be using the 'pulled eyepiece' trick myself in the future. 

Graeme

Doesn't the corrector plate have to be matched to the primary mirror?  In which case you would have to send the tube to Meade to get it fixed.  

Graeme

I feel fortunate to have built a warm control room onto my slide off shed. In there last night with an electric heater going I was warmer than if I'd been in the living room

Only managed a few 30 second Lunar videos between clouds though.

Graeme

Just now, Skipper Billy said:

It doesn't need to be level.

 

So people say but it certainly doesn't hurt that it is

I have the Altair. It's really solid and as you say has an adjustable top plate that helps greatly with getting it level.  It also has a hole in the base plate so you can route all your cables through it so long as you plan the concrete base with a bit of drainpipe through the centre.

The only problem I would say is that it's not tall enough. I'm 6 foot and initially found that with the base level with the floor I had to bend too much to look through my celestron c8.  Also, as I'd built a shed around it, it was too low within the building to see over the shed walls. In the end I added another foot of concrete to the base to lift it to where I wanted it - this also meant I could lower the top plate a couple of inches to help with stability.  as the floor is decoupled from the concrete block, the rig is as solid as the concrete it's bolted to. 

The only other point to note is that the top plate is drilled for an eq6 / Advance GT mounting puck.  I had to drill new holes to mount my EQ8 adaptor. 

I've never seen the pulsar pier so can't comment but it's worth noting that although the 2 piers are the same price, the altair one comes with mounting bolts. You have to pay an additional £45 for a fitting kit for the Pular.  (if like me you plan on fixing the mounting bolts while you pour the concrete, go with the angled bolts - they'll hold much better)

Graeme

Clear Outside is telling me Wednesday is going to be clear from 5pm right through till 3pm Thursday. As usual this coincides with a full moon  - you couldn't make it up!!

Graeme

My bit of South Lanarkshire has had TWO perfectly clear nights since the start of September. Every time it's looked clear at about 6pm, it's clouded over by 7:30. More often than not it has rained into the bargain.   Since the partial eclipse I've managed a 2 hour session on the soul nebula and a 2 hour session on Andromeda. The bbc forecast and cloudy outside all say 100% cloud for the next 7 nights.  This isn't a hobby that is in any danger of taking over my life

Graeme

When I started to take a serious interest in the skies I bought a decent pair of 10x50 binoculars, wrapped up warmly and relaxed in the garden on a reclining garden chair. Like this I spent many months just looking and taking it all in before I even thought about buying a telescope. 

Graeme

49 minutes ago, PeterC65 said:

That only works for the Stellarium App I think, not for the PC version which is what I mostly use.

On a PC/Laptop, you have to move your pointer past the left hand edge to get the toolbar up.  Same goes for the bottom edge toolbar.

If the date / time option isn't working for you then I'd suggest reinstalling Stellarium. I've had it lose contact with EQMOD once - a reinstall fixed that. 

Graeme

You can change the time on Stellarium and also change how many objects are displayed to get a very good idea of what's in the sky in the evening. 

Graeme

12 hours ago, Skipper Billy said:

Here on the NW coast of Scotland we have had one clear night since astro darkness returned at the of August!

It's been the same here just below the central belt too.  A couple of early evenings here it's looked like clearing but around 8pm the sky has vanished.  Quite disheartening.  Because we're so limited for imaging time I'm finding my images are suffering - instead of 2 or 3 nights data gathering on a single subject I'm trying to fit as many targets in as possible so for example I only managed 2 hours on Andromeda a few  weeks ago - I'd like to add to that data and my scope/camera has been left set up for just that reason but it's likely that I'll be pointing at Orion the next clear night we get. 

Graeme