First DSLR lens

[Okeydokey]

My Pentax K-m currently has the standard 18 - 55 lens,  I would like to get involved in imaging in a small way (budget) what should I be looking for?

I have the ability to piggy back the camera onto my scope, so using the rigel and an EQ3-2 mount with drive motors may help things?

I would like to do some stacked DSO images.

Many thanks

[jgs001]

You could use your kit lens, or if Pentax do a cheap 50mm prime, that's excellent for widefield. I'd actually take the scope off and mount the camera directly to the mount though.

[baggywrinkle]

It would certainly need to be driven as well. But how good the RA drives are for an EQ mount is a question, they would be the limit on your exposure times to prevent trailing.

[Okeydokey]

Oh! I was expecting something along the lines of... the Sigma 200 as a bare minimum, etc.   Nice to know, thank you both, my wife would like to pass her thanks on as well

[jgs001]

the FOV of a 50mm on a crop sensor dSLR fits Orion in nicely, to give you some idea.

[Okeydokey]

Thats brilliant John thank you very much.  The 50mm prime is certainly affordable, there are plenty about as well.  Not sure what a crop sensor is?  But getting 'Orion in' would be exactly what I hope to achieve!

[jgs001]

a full frame camera has a sensor that's the same size as a 35mm file frame. A crop sensor camera has a sensor that's a bit smaller. This has the effect that the FOV through a lens of a specific focal length is reduced on the crop sensor camera. So my 450d is a 1.6 crop sensor, when using a 50mm lens on it, the FOV (in 35mm terms) is an equivalent of 80mm. Hope that makes sense. Looking on google, the sensor size of the K-m would make it about the same size as the Canon crop sensor. However, I wouldn't worry about it too much... basically, you'll get images about the same view as I do with my Canon.

[Naemeth]

You could use your kit lens, or if Pentax do a cheap 50mm prime, that's excellent for widefield. I'd actually take the scope off and mount the camera directly to the mount though.

Was also going to suggest a 50mm prime . Excellent for widefield AP and a general use FL for daytime photography.