First DSLR atempt of Cassiopeia

[ChrisEdu]

As the title says, this is my first try at taking an image of a constellation with my DSLR. I've tweaked it a bit using Nikon Capture NX to bring out more detail (raised the RGB curves). Didn't really know what I was doing - just experimenting.

Nikon D300, 18-135mm lens (at 35mm), f/4.2, 3.5s, ISO 200 Image cropped in Capture NX

[Doc]

I like it Chris.

You can see the "W" shape.

[ChrisEdu]

It's a completely new area of photography for me, so it's going to take some time to really get the hang of it. Still at least it's meant that the Manfrotto has been put to use! Also made use of my camera's mirror lock-up facility to prevent any unwanted vibration, not that I would imagine it would be too big a problem on something like this.

[Psychobilly]

Hiu Chris,

Take a load of subs in RAW mode and stack them in DSS at 35mm FL you could lengthen the subs a bit more and still not get anyy noticeable trailing.

Billy...

[saturn5]

Chris,you should be able to get around 20sec at 35mm before trailing starts to show.

[ChrisEdu]

Hiu Chris,

Take a load of subs in RAW mode and stack them in DSS at 35mm FL you could lengthen the subs a bit more and still not get anyy noticeable trailing.

Billy...

One word -uh?! OK - I know what RAW mode is - I tend to use it when not short on space. But, when you get to subs, DSS, etc.... I'm fairly lost. As I said, I'm new to this area of picture taking.

[astro_dt]

Chris,you should be able to get around 20sec at 35mm before trailing starts to show.

Hi Chris, If it helps I have an exposure guide on my website that will help with maximum exposure depending on the lens and where you are aiming the camera (because stars towards the celestial equator move faster than those close to the pole).

It's at the bottom of the technical page

Cheers

Danny

[ChrisEdu]

I'll take a look.

[ChrisEdu]

Had a look and have a question: What's the sharpness / acceptable / accuracy stuff about?

[astro_dt]

Had a look and have a question: What's the sharpness / acceptable / accuracy stuff about?

Hi Chris

The sharpness is just a factor in the equation. The smaller the number the sharper the image.

350=pin point stars

1000=oval shaped stars

Hope that helps

Danny

[ChrisEdu]

Aha! I see.

[jgs001]

Good start Chris, the constellation is clear. If you download Deep Sky Stacker and install it. Then take at least 10 shots of the constellation, push the ISO up as high as you can get away with, I think the D300 can go up quite high without too much noise. Then put the lens cap on and take 5 shots with the same camera settings. After download, drag and drop the raw files into DSS, a popup will ask what type of frames they are, select the correct box for light (image data), darks (with the lens cap on). Click select all, click register and ok. This will align and stack the images. Then save the file, load in a picture editor and use the tutorial in here on stretching the histogram.

[ChrisEdu]

Easier to photograph squirrels!

[jgs001]

Yep, very much so

[surfindogg]

Like Chris, I have no idea what subs are. Is there a technical glossary anywhere that beginners could refer to?

You have to be careful though Chris, from what I have gather you are on the edge of a very slippery slope. One that entails addictive spending in both a financial and chronological sense. I took one image of the moon some time ago and now every time I walk past Jessops I start twitching ; )

[Psychobilly]

Rather than take a single 30 or 40 minute exposure that time is broken down into smaller chunks the duration of which depends largely on how well your moutn can track ... these are the sub exposures or subs... Using subs has lots of advantages not least iss the abillity to throw away any subs which have bad tracking, plane or satellite trails , clouds etc... it is poissibel if you have enough subs to remove plane trails usign median stacking.

DSS (Deep Sky Stacker) is a very popular free program that can stack the raw images (subs) from the camera.

Billy...