Camera Labs

Hi folks,

The southern half of Orion is a bit of a challenge for me with restricted visibility but I had a first attempt last night in Hα. I also made life difficult for myself as I was entertaining a guest but I did manage to capture 5 x 40 second subs and 2 x 1,000 second subs by leaving the camera/mounting to do it's own thing. Because I wasn't present to initiate image capture at the optimum times I ended up with both the stars Saiph and Rigel lost in either tree or chimney on the various subs so I had to crop those out.

Just two 1,000 second Hα subs is nowhere near enough but I'm encouraged to see the nebulosity connecting the Orion and Horsehead nebulae flowing on into Barnard's Loop (far left). Normally I would derive the stars from a separate set of RGB exposures but there wasn't an opportunity last night so to keep white stars I separated out the stars from the Hα image, processed and coloured the nebulosity and then added the stars (slight deconvolution and brightening) back to get the result above. The new challenge during processing this time was combining the 40 second and 1,000 second subs using PixInsight's HDRComposition tool followed by the HDRWaveletTransform tool (tutorial). Not as easy as I had hoped as both tools needed a deal of fine tuning.

Anyway, that's enough apologies from me. I hope you like the image as it stands and I certainly hope to do better if the weather allows! For orientation, north is up and the three bright stars of the belt of Orion are pretty obvious near the top of the image.

Bob.

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OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

Nice level of deepness here. Easily exceeds my attempts so far.

I still haven't finished going through the PixInsights tutorials... only got far enough to get something reasonable out.

_________________
Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.

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Thanks popo. Picking up a comment from your own thread, if you can construct a pier for your mounting it saves so much time.

I built a mould for the above ground bit which was a single pour. The foundation was almost as deep, used as much concrete and was poured a couple of weeks earlier and the two were tied together with stainless steel rebar. The circular plates are also stainless steel, the bottom one being bolted to the top of the pier using eyebolts set into the pier during construction. The top plate is adjustable and the mounting is permanently fitted to it. The whole shebang can be assembled/disassembled in ten minutes and if the holes in the plates are only just big enough for the bolts then realignment isn't needed. I just put each plate in place, hand tighten the nuts, turn each plate fully clockwise to take out the tiny amount of slack and then use a wrench to get things good and solid. As you can see from the armillary on the wall at the extreme right when the pier isn't in use it even looks slightly decorative. The major cost, apart from time, was having the metal plates laser cut but there are other cheaper solutions, especially if the supported weight is less.

Just for fun here are a couple of 100% crops from the image in the opening post:

One thing I took pains to avoid was the induced reversal of brightness so often seen in the central part of the Orion nebula as attempts are made to show the best detail. I avoided that but the cost was a much less punchy image which also ends up a little soft looking. More practice needed, methinks...

Both are subjects I want to return to in high resolution when I get the new telescope up and running.

Bob.

_________________
OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

Hmm... so deep I think the horsehead is currently the object I want to look at most. I've seen some really nice colour versions of it in the past and would love some really deep and high resolution views around it.

But anyway, I was thinking along the fixed pier arrangement too. I know my garden soil is heavy clay and shifts slowly. But if I can get a big enough foundation as well as a repeatable enough mount, I was hoping for a "set once and forget" alignment too. One to figure out before next autumn I think.

_________________
Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.

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Another two 1,000 second Hα subs of the southern half of Orion in the can as I write. I've just got time for three 1,000 second Hα subs of the half including the belt and Betelgeuse before I hit the meridian so those are just starting. RGB subs and the extreme top will have to wait for another night...

Bob.

_________________
OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

Hi popo,

With those two new 1,000 second subs in the can from last night I thought I'd see if PixInsight's "Winsorised Sigma Clipping" option could be induced to reject the Chimney/Tree induced light pollution. Bottom line was "not well enough" with just two good exposures to work with given the other two had such major defects but I found a workaround...

I'm sure there must be a way in PixInsight to select and clear selected areas of an image, probably by writing a script and doing the pixel math, but it was no problem to export the 16 bit "fits" file (my starting point) as a 16 bit "tiff", clear the problem areas to black in PhotoShop, save the result as another 16 bit "tiff" and then open up the edited image in PixInsight and save once more as a 16 bit "fits" which is the format that my files are delivered in from the camera by MaximDL. The header information can be regenerated using PixInsight's "FITS Header" tool (drag the new instance icon after selecting the header from the original image) if required.

PixInsight's Screen Transfer Function tool gives rather different looking results when auto-stretching the before and after images but the same data is still there in the image (verified by applying the same Histogram Transformation to both images), blacked out bits excepted of course, and once all the usual calibration and alignment operations are compete the ImageIntegration tool handily combines all images ignoring the blacked out areas and replacing with good image data. Signal to noise will be worse in those blacked out areas so it would always be better to grab more good subs but if you ever need to do a rescue job then this procedure might be of use...

Bob.

_________________
OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

Sounds a bit manual, but for fewer longer exposures it sounds good

I have a slight different problem myself, in that as I manually aim the camera on a ball head it never points to exactly the same place and orientation. I've been acquiring more exposure on the rosette making sure I'll cover it, but not necessarily anything else around it! Haven't tried a super-stack on that yet to see how it comes out...

On FITS, I've not looked at the options but I think mine defaults to 32-bit float? I have to remember to manually select 16 bit integer for TIF export as that seems to be the most my copy of PSE will understand.

_________________
Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.

Hi popo,

I have PhotoShop CS4 x64 and that seems to have no problem reading 64 bit floating point TIFF files but it can't save them. It can save them as 32 bit floating point but I can't see the point ( ) if one is working with 16 bit, or less, integer data direct from the camera and the only modification in PhotoShop is to clear bad pixels. But I do routinely use 64 bit floating point for all subsequent processing until the final histogram stretch prior to exporting a 16 bit TIFF as I move on to image development in PhotoShop.

In a perfect world I'd just take more subs but tonight's opportunity, if it remains clear, will be to capture as many 200 second RGB images as I can manage while the bottom half of the constellation is visible. Then it'll be one more 1000 second Hα of the top half and RGBs of that as well. Then I'll be out of time and, if the fates are kind, it will be RGB subs of NGC 7822 as I managed to capture 5 x 1500 second subs of that area in Hα last night before more tree branches got in the way!

Bob.

P.S. I still want to add the area above Betelgeuse and Bellatrix to the mosaic but the weather looks like it's turning bad tomorrow. Fingers crossed there'll be another opportunity in the next couple of weeks.

_________________
OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

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Cor, ever had a meridian flip? Had my first unplanned one this evening halfway through a set of RGBs. Normally it wouldn't matter except that the mounting is currently trained using a small telescope that isn't precisely aligned to the axis of the dovetail plate it sits on. Fine for visual work as the mounting takes that misalignment into account but with the camera plus Pentax lens mounted instead of the 'scope the blue and green subs for the top half of Orion are about half a degree offset from the red subs. Maybe the weather will be kind again in a few days and if not I'm sure I can muddle through, with a deal of extra work, and just lose some star colour at the extremes of the Hα images! Rant over.

And apologies to those who aren't into this particular game and who have no idea what I'm talking about.

Bob.

P.S. With Orion now obscured behind the house at least I can let the system run with less supervision collecting RGBs around NGC 7822. The neighbour's tree won't get in the way for another couple of hours.

_________________
OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

I crop as needed anyway so if they don't align exactly, I hope you still have a significant overlap giving a large usable area? I have no idea how much half a degree is, nor your working field of view.

I got a couple hours of the rosette yet again (in H-a) and distracted by the Stargazing program on TV earlier, I hit the end stop of the astrotrack for the first time ever. It just beeps at you. Not much good if I'm indoors with a room between the kit and me. Just packed up the kit as the clarity isn't really there tonight, and I should get an early night.

_________________
Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.

Hi popo,

Hey, my fingers still work despite disassembling the mount in -5°C. All that stainless steel acts like a heat sink when you touch it!

FoV is about 12.5° so half a degree or even more won't be a disaster. I'll know for sure how good the data is after a good night's sleep. The complication that arises is how it may or may not affect the mosaic when the two halves of Orion are stitched together. Oh well, these little problems help keep me out of the pub!

Glad you got some time in. I recorded Stargazing as I can watch it tomorrow when the cloud rolls in.

Sleep well. Hot chocolate for me and then some of the same...

Bob.

_________________
OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

Cold enough when I packed up, and worse this morning! Got a hot chocolate at work now...

Enjoy the program. Those Nasa types can certainly talk a lot. At work we got Buzz in for a corporate event, and they had to give him the "hurry up and finish" signal too!

Think I'll be processing the new data tonight.

_________________
Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.

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Another 800MB in the can tonight. All RGB shots with some 200 second green and blue exposures of the top half of Orion to replace the ones affected by the unwanted meridian flip the other night, a 200 second red of the bottom half to improve the data set and then a whole load of 8 and 40 second RGBs of the bottom half to grab the detail in the Orion nebula itself which would otherwise have been lost due to clipping.

And my fingers are finally warmed up! Processing starts tomorrow.

Bob.

_________________
OM-D E-M5 + ED 12-50mm, H-PS14042E, H-F007014E, L-RS014150E, M.ZUIKO DIGITAL 45mm 1:1.8.
Gitzo GT1541T, Arca-Swiss Z1 DP ball-head.
Astrophotography: TEC 140 'scope, FLI ML16803 camera, ASA DDM60 Pro mount.

Sounds good Can't wait until I see the result...

I wonder if my filters have arrived yet? Was out on travels yesterday so didn't check, and too tiered to even think about imaging in the evening too.

_________________
Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.