A few Watec Galaxies

[mike.brightmore]

Tonight was a brilliant night for observing galaxies. Below are quickie images of some of them captured and processed 'on the hoof'.

[ncjunk]

Excellent set of images mike! What scope was it through?

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[mike.brightmore]

Hi Neil, I was using the Celestron CPC 1100 with an f3.3 focal reducer. I have tried to make the images just like they appeared in the live view on the T.V. Monitor.

[Macavity]

Very nice indeed, Mike! You still can't beat "a bit of aperture" AND a fast f-number? While having a go at planets, I turned the MAK150 towards M3 (stars mag +11-15?). At native f/12, the Watec struggled versus the noise. With a focal reducer (to ~f/5) it wasn't too bad though.

Will hopefully give some galaxies a go, with the TS 8"/F4 Newt tonight. Almost the same limiting magnitude as an 11" SCT at f/10 (apparently)? <g> But you'd have me well beaten at f/3.3 ... The secret weapon in the armoury of the "Cat"!

Macavity/Chris

[mike.brightmore]

Good hunting. It's looking like another observing night.

[lukebl]

Nice captures. What exposures did you use?

[David Galvin]

A nice selection of galaxies, love the Sombero and the Siamese galaxies.

We have recently purchase a Watec 120n for our club (Liverpool A.S) and have only had a reasonable result imaging M42 'live' on a tv monitor. What software do you you use on your computer and does it give any control of the image brightness and contrast as some that I have tried do not appear to give this option.

[mike.brightmore]

Hi Luke

I try to keep the images looking as near as possible to the live view on the TV monitor. In fact sometimes I just photograph the TV screen (examples in the link in signature). Really the images are more like 'electronic sketches' of what I have observed. So the exposures are between 20 - 30 seconds at 25 f.p.s.

Hi David

The video grabber software is 'Cyberlink Power Director' which came bundled with the camera from Opticstar. This software does allow you to adjust brightness and contrast.

[JohnC64]

Wow they are some cracking images there. Especially like M64 and M104

John

[nytecam]

Tonight was a brilliant night for observing galaxies. Below are quickie images of some of them captured and processed 'on the hoof'.

Hi Mike - could you explain 'on the hoof' processing? I read others here are using Registax to process images.

I don't have a videocam but a CCD cam that I use in a brief exposure loop to view DSOs on my laptop like video. And how brief is an exceptable brief exposure? Equal to full video sens-up?

To show images here I need to do a quickie image process on-the-hoof but is my 'hoof' acceptable?

[mike.brightmore]

Hi Nytecam

I record a short video (AVI) usually 20 to 30 seconds directly on to the laptop. Then I import the AVI into Registax and stack it and save it as a JPEG image. If necessary I then open the JPEG image in Photoshop Elements to tweak contrast or brightness. It takes 5 to 10 minutes in total and the processing is done while I'm lining up the next target. So by 'on the hoof' I mean that I do everything while still outside at the scope. Hope that makes sense.

Mike

[nytecam]

Thanks Mike - that's answered my query nicely. I might be tempted to post a few DSO 'snaps' here - mine are single 20s-60s Lodestar-C exposures and just contrast tweaked via the cam controlling s/ware in a couple of minutes

Below is M51 in 60s - raw image seen on download

and tweaked

[nytecam]

Above is the colour straight from the cam which I find acceptable - no filters used except cam software filter removing the hideous orange London LP in my pics. Below is colour tweak via PaintShopPro-v4 that some may prefer

[nytecam]

My London LP skies untweaked below

[Macavity]

Wow, impressive stuff!

Glad this section remains active! For those with lesser aperture, worthwhile experimenting with "long" Watec settings? I like the way we are unrestricted re. posting ("on the hoof" etc.) processing here. All one big fun experiment, innit Eh?

ASIDE: This morning, "I am mostly"... VIDEO solar imaging. <G> Recently bought myself Ken H's (merlin66) book on Grating Spectroscopes. I have a "Star Analyser 100" somewhere around - So many things I might yet do with VIDEO astronomy...

[bish]

Great shots. Still saving for my watec!

[mike.brightmore]

Hi Nytecam

these are impressive images - including the extensive collection on your website. In fact they are nearly proper APs. The way I thought of it was that integrating video cams like the Watec, Mintron and even Malincams were primarily visual observing aids and kit like your Lodestars were more like quick imaging tools. It hadn't occurred to me that you could use the Lodestar for enhanced 'live' observing. What is the live image like on the laptop when in the brief exposure loop. Could you capture and post a screenshot? Personally I prefer to see the image on a TV monitor without any of the clutter you get on a computer screen, or can you view in full screen? Also I guess the live image given by the Watec is more like what you would see visually with a larger scope at a darker site, i.e. monochrome and not too photo-like.

[nytecam]

Hi Mike - here's another recent sample on M13...

Image on left as seen on laptop in 10s exposure video-like loop that I use for centring before longer exposures to max of say 60s. Yes the image is bright [via 'auto stretch'] and can fill the 15" screen .

Image on right is same 10s exposure but colour converted and log stretched later

I save all my Lodestar-C pics in raw mono as left image [for minimum file size] and pick best for colour conversion at end of session to include darks + flats - it's done with a few keystrokes via the camera controlling software.

The combo of 30cm SCT @ f/3.7 + unfiltered SX Lodestar cam make for a very 'fast' imaging system of near perfect coverage of most DSOs in brief exposures

[Macavity]

So this is an automatic (brightness / contrast histogram type) stretch function?

(Bit slow here, sometimes!)

Aside: It seems to be the "Stretch" function (within Registax) that makes the most dramatic improvement re. both integrated and snapshot Watec images? For DSOs, I set the (control box) Gamma switch to "Lo" as recommended. Still worry that the *driver* software contrast is set to "max". But will have to experiment further!

Have to "get into" darks & flats too! Once the "terminology" barrier is overcome, and the objective becomes clearer, all good stuff. Had a couple of preliminary go's at it... Not as daunting as imagined? (The process is quite well explained in e.g. the Massey & Quirk book...)

P.S. Nice images again thoughbut...

[nytecam]

So this is an automatic (brightness / contrast histogram type) stretch function?

(Bit slow here, sometimes!)

Aside: It seems to be the "Stretch" function (within Registax) that makes the most dramatic improvement re. both integrated and snapshot Watec images? For DSOs, I set the (control box) Gamma switch to "Lo" as recommended. Still worry that the *driver* software contrast is set to "max". But will have to experiment further!

Have to "get into" darks & flats too! Once the "terminology" barrier is overcome, and the objective becomes clearer, all good stuff. Had a couple of preliminary go's at it... Not as daunting as imagined? (The process is quite well explained in e.g. the Massey & Quirk book...)

P.S. Nice images again thoughbut...

Correct re auto stretch in Lodestar s/ware:rolleyes: Here my w/e DSO sampler webpage @ wpo - my Meade LX200 astrograph

[mike.brightmore]

Hi Nytecam

The more I see that more impressed I am. How does the Lodestar perform with planets?

[PeterW]

For planets you ideally want a B/W or colour DMK21 with 618 chip, fast and sensitive. I will try my B/W lodestar on saturn when I get a chance. got to say I think I now own as many cameras as eyepieces.... not that many!

Thanks

PEter

[WayBig]

Really interesting reading in this thread.

Has anyone tried a watec through a dob? If you can get such a good result from a 60 second exposure there wouldn't be very much field rotation. Would the camera software allow for the image drifting during the exposure?

A 10 inch fast dob should be able to supply enough photons as long as image drift isn't a problem

[PeterW]

Focal ratio is the main driver, so focal reducers are commonly used.

It does seem that there is a possible need to automate the little steps we apply to watec grabs and individual lodestar images so that we can "sit back and enjoy the view". anyone fancy a bit of coding, unless anyone knows of software to do the job, maybe we should all note down our processing workflow so we an learn and improve the results.

Good to see interest in this "rapid imaging" idea.

PEterW

[Macavity]

Has anyone tried a watec through a dob? If you can get such a good result from a 60 second exposure there wouldn't be very much field rotation. Would the camera software allow for the image drifting during the exposure?

A 10" / F5 Dob would give the same real-time limiting magnitude as my 8" / F4. But "literature" suggests (an arbitrary) Real-time limit of magnitude +16 - Doubtless dependent on UK local seeing, but anyway far more than yer typical galaxy surface brightness of +12... +13 etc.

Field rotation can be "sucked and seen" - Hard to predict at a particular sky location! But insignificant over the maximum 256 x 1/50 sec *automatic* integration time of the Watec for on-screen, real-time, viewing

Aside: To go "deeper", Registax seems to be able to cope with driven Alt-Az mounts - Even static (Dob) mounts? I have (stack) imaged Galactic Clusters and more, with a [fixed] Giro III. "Deep Sky Stacker" can correct for field rotation (apparently!). Experiment is the key?