The "No EQ" DSO Challenge!

[ollypenrice]

53 minutes ago, dph1nm said:

Ohh, we do you know! Except perhaps for sub-1min exposures, as the overheads in finding guide stars becomes too high.

NigelM

Can you tell us something about autoguiding in de-rotated alt-az mode? The only professional scope I know from experience is direct drive and so 'encoder guided.' This is hardly the thrust of the thread but I'm interested. I know that there are still plenty of professional EQs but are many being built these days? I thought alt az and de-rotator had become the norm.

Olly

[Bobby1970]

26 minutes ago, ollypenrice said:

We'll have to disagree amicably on that. You think the alt az mount is the right mount for AP and I don't. This doesn't mean we have to duel to the death with loaded pistols. (I hope. I don't have one!)

Olly

i am not claiming either mount as "THE" right or wrong mount. Both can be used, fact. Albeit with different results. Some people are happy with the ease of set up of their alt/az mounts and are also happy with the results they get.

Its like saying a corded vacuum cleaner is the right way to vacuum your carpet when there are alternatives.

Anyway, keep the non- EQ images coming chaps :-)

[StuartJPP]

I also like this thread, it is good to see what can be achieved with very modest equipment and an inspiration to people who have already got kit or are on a tight budget. Some people are extremely happy with the results they get and stick with it and to be honest they probably have more enjoyment capturing them than a lot of people who take it further...they also save a lot of money as well.

But the most appropriate mount for astrophotography is a mount that counteracts the rotation of the earth...i.e. an EQ mount...be that a GEM, a Barn Door Tracker, a single arm fork on a wedge or whatever it is called. A pure Alt/Azi mount keeps the target central but obviously rotates around that target. When a field de-rotator is used with that alt/azi mount it is effectively mimicking an EQ mount.

Does that mean that you can't use an alt/azi mount? Well of course you can use one, this thread proves it and that fact should not detract from what this thread is. if I had started off with an Alt/Azi mount I would have taken much inspiration from it (I was purely interested in imaging and not visual and went for a glorified barn door tracker).

Keep up the good work and with sensitive enough cameras and fast enough optics, I am sure that alt/azi imaging, perhaps with a short stroke de-rotator between images (you read that here first), will become a lot more prevalent in the future.

[wxsatuser]

On 23/02/2016 at 21:27, The Admiral said:

I don't think that there is a right or wrong, it's equipment that allows one to achieve what one wants to achieve. If this thread achieves anything it is that it dispels the myth that to do any astrophotography one has to have expensive mounts accurately aligned, with guiding to boot (the so called right equipment).

Ian

Who needs a mount when you can hand hold.

[PeterCPC]

I like this thread as well as I have a foot in both camps. I started imaging using a CPC800 and loved the fact that I could have it set up in about 10 mins and ready to start imaging. I had some modest success with it such as this M82.

However, I wanted to progress my imaging and, after getting advice from Olly and others on here, I aquired an AVX EQ mount. It is nowhere near as convenient to set up but I can still be ready to start imaging in less than 30 mins which is not bad in my view. My images are now streets ahead of what I could have achieved with the CPC800 but, I agree that you can still get some reasonaable images using an Alt/Az as long as you realise that you are never going to get the sort of images such as can be achieved with more complex arrangements.

Keep taking those images - It's a great challenge.

Peter

[SteveNickolls]

Here is a recent image of the Flame and Horsehead Nebula, taken on the 10th February 2016. It is composed from x182 thirty second light exposures, x50 dark exposures and x50 bias frames. The equipment used-SkyWatcher Synscan alt-az mount and Startravel 102mm telescope, Canon 600D DSLR at ISO 1600. The frames were stacked using Deep Sky Stacker and the resulting master image processed further using StarTools.

And here is an image of the cluster NGC 2301 (Hagrid's Dragon) also imaged on the 10th February using the same equipment and camera ISO setting. The image was produced from x46 light frames, x50 dark frames and x50 bias frames. Again the frames were stacked using Deep Sky Stacker and the resulting master image processed further using StarTools.

Cheers,
Steve

[Herzy]

Beautiful results Steve... I wish I could do that!

[dph1nm]

On 2/24/2016 at 19:50, ollypenrice said:

Can you tell us something about autoguiding in de-rotated alt-az mode? The only professional scope I know from experience is direct drive and so 'encoder guided.' This is hardly the thrust of the thread but I'm interested. I know that there are still plenty of professional EQs but are many being built these days? I thought alt az and de-rotator had become the norm.

Yes, mostly alt-az + derotator these days, but they are still autoguided. Usually picked up with either a separate ccd built-in to the camera or a moveable pick-up mirror. Of course, anything with adaptive/active optics is also guiding, almost as a side effect! There is some mention of the WHT guider here http://www.vikdhillon.staff.shef.ac.uk/teaching/phy217/telescopes/phy217_tel_ag.html

On most 2m class or above scopes I would think you would be pushing your luck to do more than a couple of minutes unguided (remember most of them have pretty small, i.e. sub arcsec, pixel sizes).

NigelM

[SteveNickolls]

Two more images (from last night).

M42 and M43 taken with a StarWatcher Startravel 102mm refractor, Canon 600D DSLR. x81 thirty second light frames, x50 dark frames and x50 bias frames. ISO 1600. Stacking using Deep Sky Stacker and further processing using StarTools.

Collinder 69 taken with the same equipment. x50 thirty second light frames, x50 dark frames and x50 bias frames. Stacking using Deep Sky Stacker and further processing using StarTools.

Cheers,
Steve

[happy-kat]

Check out filters in startools, you can lose the CA really easy quick ( I didn't even bother creating a star mask first.)

The slider on the right set it to 1 ( sorry can't see what it is called on my tablet) I read to use that setting (can't find post).

Edited February 29, 2016 by happy-kat

[The Admiral]

Nice results there Steve, and plenty of detail in the nebulae. It'd be worth a try on the Filters tool.

Ian

[SteveNickolls]

Thanks happy-kat and Ian. Whenever I try the FILTER module say to remove the halos etc nothing seems to work as the guide says. Annoying, I'm obviously not doing something. 

Cheers,
Steve

[happy-kat]

I'm having a go now and will share how it worked/did it, and find the proper post with details. hope that is alright.

[happy-kat]

I am also starting out with Startools so I am sure someone else could do better.

The first thing I did was create a star mask I tried without but the result was not right.

So open the file then select Mask.

Now select Clear to get rid of the green fill.

Pick Auto and then pick Go. I think it knows they are fat stars as I did not need to pick that option and the other option was unresponsive.

Now you have a star mask but for the filter tool you need it inverted, pick Invert. Then Keep.

So back in the main window now pick Filter, and from the menu at the bottom select Fringe Killer and set the filter width to 1.

If you next zoom in to the area of interest and pick the blue area outside of a star and each pick slowly loses the bloat. If the mask is not tight enough the the stars in mid filter use select Mask and then Grow and then Keep you get a bit more area around the stars to play with.

I think though to make it easier the star focus being as neat as possible helps though I guess there might be a tool in StarTools to tighten star shapes too.

Hope this helps and I enjoy looking at what you are acheiving with your setup.

 

[happy-kat]

Link to halo and fringe killer using startools

Eventually I hope to try with my ST80 on my virtuoso mount but I only have the mount here, so it is inspiring to see what you and others are doing.

Edited February 29, 2016 by happy-kat
Updated comment

[SteveNickolls]

Thanks happy-kat, I'll have a good bash at it tomorrow. I think I'm all StarTooled out for tonight  I will follow your directions and the link and let you know how I get on. Perhaps I'm expecting the 'fringe killer' to work wonders with a just a couple of clicks.

Thanks once again.

Night,
Steve

Edited February 29, 2016 by SteveNickolls

[Stub Mandrel]

I like this thread.

I've discovered my daughter's bridge camera will do 8-sevcond exposures at ISO1600 - mine drops from 8 seconds at ISO100 by half for every ISO increase :-(

I know she doesn't want to spend a night imaging at the scope, but I reckon she might be blown away by what such a shot will squeeze out of M42 on an ordinary tripod.

[SteveNickolls]

Good morning,

Thanks happy-kat I have tried the FILTER module fringe killer and got the following result-

Before Cr69

After

Thanks once again! Good luck with your StarTools learning curve.

Best Regards,
Steve

[SteveNickolls]

Two more images to post from last night, firstly M51. This is my second attempt imaging this object this time I used x100 thirty second exposures at ISO 1600 plus x50 dark and x50 bias frames. The equipment was a SkyWatcher Startravel 102mm refractor (f/4.9) and Canon 600D DSLR. The frames were stacked in DSS and the master resulting image processed in StarTools. The keen eyed will notice some other smaller fainter galaxies in the frame :-)

And here is my first image of a globular cluster (M3), taken with the same equipment as M51 but using x50 light frames plus x50 dark frames and x50 bias frames. Stacking and processing as for M51.

[calli]

@SteveNickolls Aeee, thats nice. I could not found what mount you use?

Carsten

[SteveNickolls]

Sorry calli, my omission. The SkyWatcher Startravel came with a Synscan Go-To alt-az mount.

Cheers,
Steve

[happy-kat]

Those have come out very well, StarTools is coming up trumps.

[The Admiral]

Some nice images there Steve. I particularly like the M51; that's one I'll target whenever it's position becomes favourable. I think that there is a hint of colour coming through there too.

Ian

[The Admiral]

You can always tell when we've had a rare clear night, there's a burst of activity  (and hopefully the atmospheric disturbances aren't doing the same as to this little chap!)

Prompted by the rather splendid image of the Leo Triplet (M65, M66, and NGC3628), posted by Barry-Wilson very recently, I wondered what would be achievable using the short subs approach. Here's what I managed to get last night, stacking 95 x 30sec subs, 54 darks, and 41 bias in DSS and processing in Star Tools. Equipment: Fuji X-T1 at 1600ASA, through an Altair 102mm f/7 Super ED, all mounted on a humble Nexstar 6/8SE mount, 7th March 2016.

 

Personally, I'm rather pleased with the way it's turned out, and I hope that you like it too.

Ian

Edited March 9, 2016 by The Admiral
Wrong date!

[The Admiral]

I've not had a go at imaging a globular cluster before, and Steve's M3 was to be a likely contender, but M53 put in an appearance somewhat earlier so I had a go at that.

I stacked 47 x 30sec subs, 54 darks, and 41 bias in DSS and processed in Star Tools. I did a bit of tweaking in Picture Window Pro. Equipment: Fuji X-T1 at 1600ASA, through an Altair 102mm f/7 Super ED, all mounted on a Nexstar 6/8SE mount, 7th March 2016.

 

Ian

Edited March 9, 2016 by The Admiral
Wrong date!