The "No EQ" DSO Challenge!

[Filroden]

Typical...it was supposed to be completely clear tonight so I "accidentally" treated myself to a Canon EF85 f1.8 lens to try my hand at some wide area imagery. It fits neatly on my mount and allows me to go to the Zenith. Oddly, until I can find a way to attach a shoe, I am going to have to put the scope on the mount to use Starsense, then swap to the camera/lens. Thankfully, it's a quick process.

There are just too many wide area images of interest to miss out on the fun. Plus, I still have too much data to process on my four main targets!

[happy-kat]

It is a nice lens I have it, it might need stopping down if the target has very bright stars, I used f4 for M42 but it's a super nice lens and very quiet. There is a lens profile for it too in Canon utilities from memory.

Edited December 1, 2016 by happy-kat

[Filroden]

I just have to figure out how to stop it down. It may need to be masked to reduce its aperture.

[SteveNickolls]

Hi Ken, I don't know about 'great minds' etc but this may solve your connection issue-http://www.rothervalleyoptics.co.uk/geoptik-slr-hotshoe-synta-finderscope-adaptor.html I have also read you can use parts from curtain fixings to go into the camera hot shoe then connect them to a finder. BTW did you beat me to the Canon 85mm f1.8 lens on mbp.com? :-)

Good luck with your wide field imaging.

Cheers,
Steve

Edited December 1, 2016 by SteveNickolls

[happy-kat]

I have seen an adaptor for the hot shoe much cheaper than that. Might be the German telescope place or 365 astronomy.

Edited December 1, 2016 by happy-kat

[SteveNickolls]

http://www.365astronomy.com/Blitz-Hotshoe-dSLR-Camera-Adapter-and-Deluxe-Multi-Reticle-Red-Dot-Finder-COMBO.html

I'm almost sure I once had one of the hot shoe adapters but it did not fit well being too loose.

Cheers,
Steve

Edited December 1, 2016 by SteveNickolls

[Filroden]

27 minutes ago, SteveNickolls said:

Hi Ken, I don't know about 'great minds' etc but this may solve your connection issue-http://www.rothervalleyoptics.co.uk/geoptik-slr-hotshoe-synta-finderscope-adaptor.html I have also read you can use parts from curtain fixings to go into the camera hot shoe then connect them to a finder. BTW did you beat me to the Canon 85mm f1.8 lens on mbp.com? :-)

Good luck with your wide field imaging.

Cheers,
Steve

Not guilty! I went to John Lewis. 

And my camera doesn't have a hot shoe. I will need to fix it via a ring I think. 

Edited December 1, 2016 by Filroden

[SteveNickolls]

He, he I'll let you off then :-) Nice lens. Sure you will get lots of enjoyment from it.

BTW there were three of them 2nd hand on mbp.com all very good, two were virtually new.

Cheers,
Steve

Edited December 1, 2016 by SteveNickolls

[Filroden]

2 minutes ago, SteveNickolls said:

He, he I'll let you off then :-) Nice lens. Sure you will get lots of enjoyment from it.

BTW there were three of them 2nd hand on mbp.com all very good, two were virtually new.

Cheers,
Steve

I do like my two year warranties and the opportunity to take it back if I don't get on with it

[Filroden]

And thinking about the starsense. It's calibrated for the scope so for the extra few minutes putting it on and taking it off the mount (I don't have to do anything with it) will be quicker than recalibrating the Starsense each time I swap it.

[Filroden]

M42 and the Running Man

I finally processed the 405 additional lights I took on 29 November. Boy, were they a pain. Having taken the additional 1s RGB exposures to gain some needed colour detail in the core I could not calibrate them. No combination of bias, darks or flats gave a result that wouldn't have harmed the overall image so I didn't use them. Thankfully I'd taken a full series of 5s exposures and these seem to give enough detail. Here's the capture details:

As for processing this second version, although I've tried to replicate the steps in my original version I have a very different image. I had to do a different crop due to additional rotation and the two nights not being quite aligned centrally but I don't think I've lost too much due to that. However, the colours produced a very different balance this time and I'm not sure which I prefer. I have not yet blended in the older SCT data of the core as I think this one has retained enough detail.

*Edit* I forgot to also add that the last session was done at unity gain (139) compared to the rest at 300. I think that's helped the dynamic range and might explain the improved star colours.

Version 2

Version 1 for comparison

 

Edited December 2, 2016 by Filroden
Unity gain details

[The Admiral]

Here's another from a couple of nights ago, NGC6888 Crescent Nebula. This was not in my darkest direction, running the gauntlet of sky-glow from the local town. It was taken after the Veil nebula and so it was starting to get a bit low in the clag. This is the result of 121 x 30s lights at ISO1600, stacked in AA using the master bias for both flat-darks and darks. Still looks a bit 'mucky' despite being given a right buffing-up in Lightroom. Not one of my best, really needs more subs taken at a higher altitude.

Taken with a Fuji X-T1 through an Altair 102mm f/7 Super ED with a TS Photoline 2" 0.79x reducer/flattener. Mounted on a Nexstar 6/8SE Alt-Az mount. RAWs stacked in Astroart, processed in StarTools, and finished in Lightroom.

Ian

[Filroden]

1 minute ago, The Admiral said:

Here's another from a couple of nights ago, NGC6888 Crescent Nebula. This was not in my darkest direction, running the gauntlet of sky-glow from the local town. It was taken after the Veil nebula and so it was starting to get a bit low in the clag. This is the result of 121 x 30s lights at ISO1600, stacked in AA using the master bias for both flat-darks and darks. Still looks a bit 'mucky' despite being given a right buffing-up in Lightroom. Not one of my best, really needs more subs taken at a higher altitude.

Taken with a Fuji X-T1 through an Altair 102mm f/7 Super ED with a TS Photoline 2" 0.79x reducer/flattener. Mounted on a Nexstar 6/8SE Alt-Az mount. RAWs stacked in Astroart, processed in StarTools, and finished in Lightroom.

Ian

To be fair, you've captured some fine structures in the nebula and it's only the noise from the sky that's impacting the overall image. If you could catch it higher next time you should be able to reduce the noise considerably.

[The Admiral]

42 minutes ago, Filroden said:

M42 and the Running Man

I finally processed the 405 additional lights I took on 29 November. Boy, were they a pain. Having taken the additional 1s RGB exposures to gain some needed colour detail in the core I could not calibrate them. No combination of bias, darks or flats gave a result that wouldn't have harmed the overall image so I didn't use them. Thankfully I'd taken a full series of 5s exposures and these seem to give enough detail. Here's the capture details:

As for processing this second version, although I've tried to replicate the steps in my original version I have a very different image. I had to do a different crop due to additional rotation and the two nights not being quite aligned centrally but I don't think I've lost too much due to that. However, the colours produced a very different balance this time and I'm not sure which I prefer. I have not yet blended in the older SCT data of the core as I think this one has retained enough detail.

That's a lovely image Ken, well done, and again, congratulations on your persistence , which is clearly paying off. I prefer your v2 for colour. Your short exposures to capture the core really are a heads up here, as I've been wondering what sub duration I should use when I get around to it later this year/early next. I plan on blending two sub durations so that will be a first for me.

Ian

[Stub Mandrel]

47 minutes ago, Filroden said:

However, the colours produced a very different balance this time

A really good image. It seems to be possible to get almost ANY colours out of M42 except the ones you want!

[Filroden]

1 minute ago, The Admiral said:

That's a lovely image Ken, well done, and again, congratulations on your persistence , which is clearly paying off. I prefer your v2 for colour. Your short exposures to capture the core really are a heads up here, as I've been wondering what sub duration I should use when I get around to it later this year/early next. I plan on blending two sub durations so that will be a first for me.

Ian

The 1s L was good enough (it even showed the Running Man) but I messed up the 1s RGB. That said, I don't think I really lost much in using the 5s subs instead. My camera is probably 2-3 times more sensitive so you may want to test 5-10s subs for the core?

[Filroden]

2 minutes ago, Stub Mandrel said:

A really good image. It seems to be possible to get almost ANY colours out of M42 except the ones you want!

I've noticed that. And my new colours are growing on me. I like the more graduated balance between the Running Man and M42 and I like the warmer tone. I'm going to upscale the image and see if I can get it printed at about 60cm x 60cm but I need to find a printer that will be able to retain the contrast.

[Filroden]

NGC1333

I think I've hit a little bit of a wall on this one. Added some more data so this is now at 3hrs L and 1hr each of RGB. I think I'll move on to my other projects now - adding more data to the HH and Flame and starting on the Rosette and also to do some wide field.

Version 6

[happy-kat]

It's a super image and has shown the benefits of adding more data, perhaps you've as you say reached the point to close that one off.

I'm not giving up while stones are unturned. Today tested and confirmed the mount is tracking and what you do when it stops tracking when using the handset when taking advantage of freedom find. Plus astroboot have just got in camera hotshoe mounted red dot finders so have one of those on order.

[Nigel G]

There's some fantastic images posted recently, to be quite honest far better than I thought was possible with Alt-Az mounts., I'm sure we're far from the limits still.

If only admin would agree to a new forum to organise the ton of information that has been gathered and posted over the last year or so, I still struggle to find past data to refer to. I have a list of pages for certain bits, but it needs organisation of some kind. 

Keep them coming guy's. 

I have been experimenting a bit  with old and new data, mixing ISO, lots of subs, few subs, no darks, no flats, different mixes. 

Will post some results later today

Nige

 

[The Admiral]

15 hours ago, Filroden said:

The 1s L was good enough (it even showed the Running Man) but I messed up the 1s RGB. That said, I don't think I really lost much in using the 5s subs instead. My camera is probably 2-3 times more sensitive so you may want to test 5-10s subs for the core?

I used 15s subs when I last attempted it, and that was without a 0.79x reducer, which I plan on using next time. I also plan on using ISO400 rather than 1600 which should give me a bit more DR. So I agree, 5-10s looks to be the likely range. The next question, what proportion of imaging time should be devoted to short exposures and what to long? Looks like a few experiments will be needed - let's hope our weather co-operates .

Ian

[Filroden]

1 minute ago, The Admiral said:

I used 15s subs when I last attempted it, and that was without a 0.79x reducer, which I plan on using next time. I also plan on using ISO400 rather than 1600 which should give me a bit more DR. So I agree, 5-10s looks to be the likely range. The next question, what proportion of imaging time should be devoted to short exposures and what to long? Looks like a few experiments will be needed - let's hope our weather co-operates .

Ian

I only did 60 x 1s L and 30 x 5s LRGB. That doesn't seem to have harmed the image. That said, at such quick exposures it's not difficult to collect double or triple that.

[Filroden]

NGC1333

I couldn't put it to bed (and it had been pointed out how magenta the background was in comparison to v5). So I found a really good tutorial on using PixInsight which had a lesson on removing stars so you could work on the background, then re-blend the images - all within PixInsight (whereas before I'd have transferred into Photoshop). So here's v6.5.  This is the same data as v6 but I've pushed the background much harder (probably too hard) and balanced the colour a little better.

Version 6.5

I'm now not sure whether to continue. I really need darker skies and better seeing (don't we all). I'm tempted to weed through the subs again and reduce the total number, only letting the best through but then I'd need to capture many more subs. This is already 6 hours of data collection - far beyond anything I've done before - and it has eaten 31Gb of hard disk to store the 500+ calibrated images. So, sticking to Plan A and testing wide field for a while and I may come back to this next year.

[wxsatuser]

17 hours ago, Filroden said:

M42 and the Running Man

I finally processed the 405 additional lights I took on 29 November. Boy, were they a pain. Having taken the additional 1s RGB exposures to gain some needed colour detail in the core I could not calibrate them. No combination of bias, darks or flats gave a result that wouldn't have harmed the overall image so I didn't use them. Thankfully I'd taken a full series of 5s exposures and these seem to give enough detail. Here's the capture details:

As for processing this second version, although I've tried to replicate the steps in my original version I have a very different image. I had to do a different crop due to additional rotation and the two nights not being quite aligned centrally but I don't think I've lost too much due to that. However, the colours produced a very different balance this time and I'm not sure which I prefer. I have not yet blended in the older SCT data of the core as I think this one has retained enough detail.

*Edit* I forgot to also add that the last session was done at unity gain (139) compared to the rest at 300. I think that's helped the dynamic range and might explain the improved star colours.

Version 2

Version 1 for comparison

 

Although both images are very good the first is closer to true colour.
Most of M42, contrary to most images you see, is blue reflection nebula.
This blue is mainly around the outside with the inside containing Ha, there is some teal around
the Trapezium for the OIII.

 

[The Admiral]

7 hours ago, Nigel G said:

There's some fantastic images posted recently, to be quite honest far better than I thought was possible with Alt-Az mounts., I'm sure we're far from the limits still.

I suppose at the back of my mind is that the sort of mount used shouldn't  impact on the quality of images that can be obtained, with a few provisos. One is that the precision of tracking with AZ mounts, and hence star streaking, is unlikely to be as good as a properly tuned EQ mount. (May be we need mounts specifically designed to cater for this sort of imaging, but that of course is breaking with established doctrine). This will lead to somewhat larger stars once stacked, though I guess with enough subs one could ruthlessly discard any showing a hint of movement. Ultimately, though, this will result in a reduced total exposure per session. Also, the field rotation constraints mean that our imaging 'window' is quite limited compared to EQ mounts (i.e. 2 or 3 hours compared to all night), requiring a number of imaging sessions on a given target in order to build up sufficient quality, and the co-operation of the weather to achieve this. AZ imaging time is precious! Further, we are probably constrained to below the optimum exposure times, but for many in rather less than the ideal dark sky conditions, this may not be a particular constraint.

Well, perhaps I've argued against myself here , though I think we all know that AZ imaging does  impose constraints, but I still feel that if we get it right then there should be no reason not to be able to match the quality of the best images produced using the 'conventional' paradigm. Heavens, we are already producing images which are better than some produce using all the fancy gear, but that's another story . But we still do have something to aim for - getting it right is not so easy!

Ian