Lambda Cen. in Narrow Band with 150mm Achro

[avandonk]

Managed to get the fridge fitted to the Skywatcher 150mm F5 Achro and get some data at -4.0C through various filters. For info on scope seehere
http://www.iceinspace.com.au/forum/s...ad.php?t=28500

Large image 1.4MB
http://members.optusnet.com.au/~trlee8/lambdacar.jpg

Details

I focused the Neb filter for blue and green ie both in focus the red with an achro is then a bit out of focus. You could then focus for the red with the neb filter and collect again. so anyone could do this simply with a nebula filter and an achro. A good nebula filter such as the hutech is basically a moderate narrowband for HA, Hb and O3 all in one. It is the blue that is shorter in wavelength than Hb that gives violet rings in an achro.

Canon 5DH, 150mm F5 SW achro with Hutech FR/FF so actually f/4.5. Cooled to 2.0C at start and at -4.0C by early morning. Thats about 23C below ambient.

Exposures 10x4min at an ISO 1600 for Astronomik HA and O3, and Hutech Nebula filter.So three sets of data. Notice the lack of noise that is present when an ISO of 1600 is used. The HA and O3 was collected with the Moon present. The nebula filter data was collected after the Moon set.
Converted from Raw to Tiff and corrected for flats with ImagesPlus.Stacked and aligned with Registar.

Blended in ImagesPlus the following way

Operation : Auto Color Combine
Color Model : RGB
Red Operation : ADD
Number of Components : 1
File 1 : haLrg_R1.fit
Green Operation : ADD
Number of Components : 2
File 1 : 03Lrg_G1.fit
File 2 : nebLrg_G1.fit
Blue Operation : ADD
Number of Components : 2
File 1 : 03Lrg_B1.fit
File 2 : nebLrg_B1.fit

Adjusted for levels and curves in PS.


I think this shows a lot of promise for very faint nebs and SN remnants.

Can anyone spot the Planetary Nebula?

Bert

[citivolus (Ric)]

Interesting, that area seems to have good potential for a deeper shot as well.

There is a dark nebula in the upper left, as well as the planetary you mentioned hiding out elsewhere There is a lot of detail hinted at around the dark area as well.

Regards,
Eric

[Karlsson]

Originally Posted by avandonk

I think this shows a lot of promise for very faint nebs and SN remnants.

Can anyone spot the Planetary Nebula?

Bert

What I find really interesting is the little globules in IC2948 that stand out so well.

The PN (He 2-72) is quite easy to spot as well, to the lower left of lam Cen.

[tornado33]

Very detailed image there. Love those dark Thackarays Globules in the nebula
Scott

[monoxide]

nice shot Bert,
i wondered how an achro would do with a UHC filter and it looks like it does well.

the fridge looks like its doing well too, nice and smooth for iso1600

[iceman (Mike)]

Lovely image Bert, always pushing the boundaries.

[theodog (Jeff)]

Nice polished image Bert.
I will have to look into this area in future.
Well done

[avandonk]

Here is a better version now with Hutech nebula filter red data and better processing.

Ha + O3 + Nebfilter all respective colours added in ImagesPlus.

Again 10x4 min at 1600 ISO. In the fridge and from about the time the Moon set and after.

Large Image 2.0MB
http://members.optusnet.com.au/~cheekyfish/LCENT.jpg

This is an image done completely with an Achromat ie a Skywatcher 150mm F5. It has been modified to minimise vignetting and field curvature. Just shows what can be done with a bit of ingenuity.

I will collect full spectrum data with the 100ED to produce a HDR image and that when added will 'colour in' the stars.

I hope to get full colour images of very faint SN remnants with this system.

Bert

[Peter Ward]

Not bad Bert.

I'd try an get rid of the dark cyan rings around the stars...thinking of which, they all look to have been saturated to white and show very little colour variation.

[avandonk]

Peter you are correct that the brighter and not so brighter stars are saturated. All exposures were for 4 min at an ISO of 1600 and at FL of 675mm at f/4.5 so its not surprising. With future blending will do a full spectrum HDR with the 100ED and only use narrow band for the nebula data from the achro.

What is interesting how good the achro is with the neb filter. I think for a $800 OTA the results are much better than expected. I would hate to think how expensive a 150mm diameter F5 APO would be. Assuming it could be built.

I am very pleased at the performance of the achro with 13nm narrow band filters. With careful focusing the star size is comparable to the 100ED actually better at the O3 end of the spectrum due to the larger aperture. Which is what you would expect. I was warned and aware about spherochromatism being a problem but I ignored it.

See here for HA and HDR blended
http://www.iceinspace.com.au/forum/s...ad.php?t=28862

Bert

[avandonk]

Here is just the narrow band data merged with ImagesPlus.
HA red to RED, O3 green to GREEN, O3 blue to BLUE.

Large image 1.5MB
http://members.optusnet.com.au/~trlee8/LCENTnb.jpg

It is obvious that the achromat when focused accurately for each respective filter does a pretty good job.


Bert

[tornado33]

Yes a great idia using narrowband imaging to get around an instrument that might focus different colours differently.
Scott

[Prickly]

Wonderful image. A Baader UHCS filter is also very nice with achromats and has the added benefit of helping with imaging from the suburbs.

Keep em coming!

David

[robin]

Fantastic image Bert. Love it.