My version of M42 - colour advice needed please.

[StuartJPP]

I am considering modding a camera (Canon 1100D or similar) and was wondering what difference this would make to the colours of something like Orion Nebula straight out of the camera. I know it will make a huge difference to the likes of The Horsehead nebula which has got a lot of Ha, but what about M42? The colours in this image are straight out of the camera, slightly tweaked but basically what was there. Other images I have seen are more pinkish as opposed to purple. I realise that the core is burnt out, because I only had about a 20 minute window and didn't get time to shoot some shorter exposures that I knew I needed before it went behind the roof. Definitely on my redo list.

As an aside, this was my first ever sighting of M42, I had been waiting for it since I took an interest in astro in May. I was ready for it and prior to it rising I was shooting NGC1499 California Nebula (which didn't come out very well at all and why I'd like to mod a camera).

Canon 7D (unmodded) with Canon 500mm f/4 L IS

Astrotrac TT320

Stacked in DSS, processed in PS.

18x 60 second Lights @ f/5.6, ISO 1600

10x Darks

10x Bias

11 Nov 2012

Great Nebula In Orion (M42) by StuartJPP, on Flickr

[StarRaver]

stunning image

[Gina]

Good for an unmodded camera There is an enormous amount of Ha in M42 (see my thread) - modding a DSLR makes a big difference.

[Tim]

There is probably more Ha, and brighter than anywhere else in the sky that I can think of, in M42.

Check out SteveL's APOD of the area here for an indication of the scale of the emissions in this area.

http://apod.nasa.gov/apod/ap101005.html

A modded camera will improve the response of the camera no end to these red emissions, but the result will still be less than that acquired by a mono camera with Ha filter, so dont be despondent if you dont seem to capture as much of the emission as some images seem to.

Great framing on this one btw

Tim

[steppenwolf]

The colours in this image are typical of those from an unmodified DSLR camera. This object like any other emission nebula would respond well to a modified DSLR as this would release more of the red colours that you are seeking.

[RAC]

Awesome. I would love to see a big crop of some stars from the center and corners from that lens wide oped and stopped down a little.

[sologuitarist61]

Lovely image

[StuartJPP]

Thanks everyone, I am leaning towards a modified Canon 1100D. Just got to pluck up the courage to do it.

RAC - Here's a couple of 100% crops from the centre and from the bottom left.

Canon 500mm f/4 L IS at f/4 (Top Left is centre of main image, Bottom left is bottom left of main image. Main image is resized original)

Canon 500mm f/4 L IS at f/5.6 (Top Left is centre of main image, Bottom left is bottom left of main image. Main image is resized original)

[RAC]

well not alot wrong with that is there. some guy has some tests on the net of these IS telies and didnt like them for astro work.

Thanks.

[StuartJPP]

well not alot wrong with that is there. some guy has some tests on the net of these IS telies and didnt like them for astro work.

Thanks.

I have read many reviews/forums of using this lens for astro with mixed results. I didn't buy it for this purpose as I use it for birding, but I think it does a fairly decent job to be honest, not that I have got anything to compare against. It obviously doesn't perform as well as a similar priced dedicated refractor but then a astro refractor wouldn't have IS, auto-focus etc. Since I have already got it I might as well use it.

I am not particularly fond of the diffraction spikes when stopped down so I try to avoid that now and either take shorter subs or reduce the ISO.

[Chris]

good work! some really nice pics recently with camea lenses and this is one of them:)

[Tom OD]

nice but I think you've clipped it

[ollypenrice]

Tom's right. It is a little black clipped.

It has a strong magenta caste which suggests that the green needs to be lifted. You can see this from the fact that everything in the image has this caste, including the blue stars. M42 is an odd one because, although it has strong Ha emission, it is not ALL Ha and has other colours at varying distances from the Trap.

When balancing colour try to get the top left of the Histo peaks for each channel to lign up, something I learned from Tom when we were starting out.

Your image has a lot going for it!

Olly

[StuartJPP]

Yep it is clipped, this was an 18 minute session and I think represents the colour I will get with an unmodified camera.

The above crop colours are not representative as they were just screen captures from my RAW processing software which probably applied some default WB adjustments. After stacking the colours are much better.

I'll have another go with this data and see if I can bring out a bit more detail in the darks without it looking blotchy. I won't be able to do anything about the blown highlights though, they are gone for good.

Thanks for the tips.