complete widefield noob first image and questions

[mindburner]

hi

I have a number of DSLR cameras so I decided to give them a go last night . I must say I found it much more challenging than using a large refractor and CCD.

The first is veil nebula with a Canon 1100d and a SMC takumar lens 200, stepped down a bit. The CA was horrendous and DSS seems to have stripped all the colour out of the shot. This is 7x3 mins. guided (badly) as I didn't get my camera rig sorted out properly. A baader LP filter was fitted to the front of the lens. I also have the little plastic 50mm lens, so may try that.

This was done on a Pentax K-3

1x6mins I believe

Camera seems to have good noise levels but..

it came out very blue not sure why and I can't seem to recover the colour in this one.

finally a few Questions:)

IS there a kit one can get to mount a DSLR and a guide to a vixen. Ot is just a matter of getting aluminum bar and bodging something

Better lens than the Takumar, maybe Canon 200mm prime?

[mindburner]

this is the 'rig' that I bodged together. 

[JRWASTRO]

Greetings Mind burner,

Re: Better lens than the Takumar, maybe Canon 200mm prime?

May I suggest that you look at the Canon 400mm f5.6 lens. This is a prime lens very simple in optical construction and very well corrected. Most kit lenses are woeful when applied to astro stuff even my Canon 85mm f 1.2 lens has depressingly high CA when one takes a 15 sec exposure but , at least, the picture looks very pretty.

I have taken pictures with 900 sec exposures (RAW files) on a Canon EOS 350D relied on the in camera noise reduction ( which is very good) converted the RAW files to *.tif files and stacked the tif files. The pic of Omega Centauri on the left is taken using the above procedure using a Canon 350D.

Jeremy.

Jeremy.

[mindburner]

hi

manythanks for the reply. I shall check out the 400mm lens. I only have a 1100d at the moment for astro work, and my other cameras do not seems as suitable for astro work as the Canon. 

I have a 427 atik CCD which is super but the actual chip is small for WF

I basically want to get a decent wide field setup that I can use with my EQ6 and maybe also with a more portable tracking system for use at dark sky sites.

I used to use a 1100d and convert the RAW to tiff as you do with my refractor and the result was great. 

[spaceboy]

From what I gather the 1100D 12MP doesn't suffer noise as bad and so is somewhat better suited to astrography than some of the other low to mid range priced 18MP DSLR's

[JRWASTRO]

hi

manythanks for the reply. I shall check out the 400mm lens. I only have a 1100d at the moment for astro work, and my other cameras do not seems as suitable for astro work as the Canon. 

I have a 427 atik CCD which is super but the actual chip is small for WF

I basically want to get a decent wide field setup that I can use with my EQ6 and maybe also with a more portable tracking system for use at dark sky sites.

With the Canon 1100D and the EF 400mm / f5.6 lens you will get to photograph an area of 3.2 x 2.1 degrees ... not too bad. You will get a good shot of the Andromeda Galaxy.

If you use a Standard 50 mm lens say a 50mm f1.8 your DSLR will photograph an area of 25.4 x 16.8 degrees that will get some good shots of the Milky Way.

About mounting the camera on the EQ6. There are simple brackets available where the DSLR is attached to the weights bar. This is a very simple setup. Available in the shops here are many styles of mounting bar that would do what you want:

http://www.myastroshop.com.au/products/mount-access.asp

I am sure there are suppliers in the UK that carry similar products.

Jeremy.

[mindburner]

From what I gather the 1100D 12MP doesn't suffer noise as bad and so is somewhat better suited to astrography than some of the other low to mid range priced 18MP DSLR's

hi

My current 1100d is pretty bad at ISO 800 compared to a previous T3, US version which was amazing for low noise at ISO800. Seems pretty strange but the long dark subs were much better on the US model.

ISO1600 seems pretty good on the 1100D though.

My 24MP K-3 seems great but the images came out very blue, so I am not sure what is going on here

[mindburner]

With the Canon 1100D and the EF 400mm / f5.6 lens you will get to photograph an area of 3.2 x 2.1 degrees ... not too bad. You will get a good shot of the Andromeda Galaxy.

If you use a Standard 50 mm lens say a 50mm f1.8 your DSLR will photograph an area of 25.4 x 16.8 degrees that will get some good shots of the Milky Way.

About mounting the camera on the EQ6. There are simple brackets available where the DSLR is attached to the weights bar. This is a very simple setup. Available in the shops here are many styles of mounting bar that would do what you want:

http://www.myastroshop.com.au/products/mount-access.asp

I am sure there are suppliers in the UK that carry similar products.

Jeremy.

ho

good advice there. I have the great little 50mm 1.8 lens and never though of trying it out. 

I will maybe give this a sin before buying any larger lenses.

Would you know if it ok to put filters on the front of the lens. My sky is getting more and more light polluted so I need to use a Baader LP filter mounted on the front. I may get a clip in filter if there are any issues though.

I will investigate the DSLR mounts and see if I can add my guider to it too, 

[JRWASTRO]

ho

good advice there. I have the great little 50mm 1.8 lens and never though of trying it out. 

I will maybe give this a sin before buying any larger lenses.

Would you know if it ok to put filters on the front of the lens. My sky is getting more and more light polluted so I need to use a Baader LP filter mounted on the front. I may get a clip in filter if there are any issues though.

I will investigate the DSLR mounts and see if I can add my guider to it too,

Putting filters in front of the lenses presents a problem in obtaining an astronomical type filter that will screw onto a standard 50mm lens. Very good anti- light pollution filters are available and these do a brilliant job for visual observations but do alter the colour balance in the photographic image. Putting the filter on the back of the lens gets complex and besides it will cause major problems with focusing as the distance from the back of the lens to the CCD plane is critical.

Light pollution is a major problem. There are some excellent programs (expensive) that do a good job of removing it. I have Photoshop CS3 and use a rather brutal method of removing the colour cast by creating an estimate of the light pollution as a separate layer then subtracting this layer from the picture.

Jeremy.

Jeremy