The Core

[cafuego (Peter)]

But not like that terrible, terrible movie.

No Moon means you can use shorter focal length glass, right? This is an 294MC staring at the galactic center for five hours through a zwo duo filter and a Sigma Art 35mm f/1.4 (stopped down a bit)

Unfortunately, modern DSLR (and probably mirrorless) lenses come without manual aperture rings, which means you need to wedge bits of plastic into their mechanism if you want to stop them down a bit for shaper images. Still waiting for the DSLR/M42 adapter manufacturers to catch on and add aperture rings to their products.

In the mean time, I didn't stop this one down enough and didn't focus quite right, so there is a spot of coma and blurriness.

I like the field of view though, all the bright Ha menagerie from the Prawn to the Eagle ;-)

[Dave882 (David)]

Nice one Peter it’s a beautiful widefield and nicely framed too!

[AstroViking (Steve)]

Very nicely done!

[Plossl68 (Paul)]

Hi Peter,

Love the image.

Just on your plastic wedges, I don’t know about Sigmas, but with my Canon lenses, when I want to stop them down to use on an Astro camera, I pop them on my dslr, stop them down and then remove them without turning the camera off and voila, they hold whichever f-stop they were last set at. Yes, it’s a bit finicky if you want to try multiple f-stops, but no need for wedges.

Cheers,
Paul

Originally Posted by cafuego

But not like that terrible, terrible movie.

No Moon means you can use shorter focal length glass, right? This is an 294MC staring at the galactic center for five hours through a zwo duo filter and a Sigma Art 35mm f/1.4 (stopped down a bit)

Unfortunately, modern DSLR (and probably mirrorless) lenses come without manual aperture rings, which means you need to wedge bits of plastic into their mechanism if you want to stop them down a bit for shaper images. Still waiting for the DSLR/M42 adapter manufacturers to catch on and add aperture rings to their products.

In the mean time, I didn't stop this one down enough and didn't focus quite right, so there is a spot of coma and blurriness.

I like the field of view though, all the bright Ha menagerie from the Prawn to the Eagle ;-)

[cafuego (Peter)]

Originally Posted by Plossl68

Hi Peter,

Love the image.

Just on your plastic wedges, I don’t know about Sigmas, but with my Canon lenses, when I want to stop them down to use on an Astro camera, I pop them on my dslr, stop them down and then remove them without turning the camera off and voila, they hold whichever f-stop they were last set at. Yes, it’s a bit finicky if you want to try multiple f-stops, but no need for wedges.

Cheers,
Paul

There's a spring in the mechanism for the Sigma Nikon lenses, which makes the aperture always jump back to as small as possible when the lens isn't installed. The same is true for Nikon lenses, for that matter

[Plossl68 (Paul)]

Darn it. Clearly they need to think more broadly about just where their excellent lenses are destined to be used.

Originally Posted by cafuego

There's a spring in the mechanism for the Sigma Nikon lenses, which makes the aperture always jump back to as small as possible when the lens isn't installed. The same is true for Nikon lenses, for that matter