Atik Infinity Compatibility with Dob

[m11]

Hi Atik Support,

I am interested in the Atik Infinity Colour and was wondering if:

Is it  compatible with a 1800mm Focal length Dobsonian Telescope (xx16g)?
Does it require additional spacers/powermates/barlow to get focus?

Thanks,

M11

[Jo]

Hi M11,

Sorry for the delay.

It would work, but to what extend would depend on a couple of things. The first is whether you having any tracking on the scope? You really need some kind of tracking to make the most of the Infinity. You're also at a fairly long focal length, so, particularly combined with how good your tracking is, you might find you're limited as to how long you can expose for.

I hope that helps,

Jo

[scpanish]

I just got a mono Infinity for use with the 10" 1200MM FL Skywatcher goto dob.  One session isn't definitive, but infocus was OK - barely.  Sensitivity fine.  The major problem was focus  / sharpness.  The numeric FMHW numbers were always large, typically around 20.  Visually, I can focus more finely.  Even with a .1 sec exposure, focuser travel that I know was significant with an eyepiece did not improve the image, which was never decently sharp.  At one point I got the numbers down below 4, but there was no apparent improvement in sharpness, and variability in the readout was high.  My concern with this setup has always been that the fine tracking movements are not sufficiently accurate with the Synta Dob drive, although the images remain perfectly stable on the screen and the goto accuracy is great.  I have not thought of a good way to test this, but it would account for the sort of blobby images.

But - I've only used the camera once and there were many clouds so I never got a good long time to concentrate on a given stellar object.  More later.

Steve

[scpanish]

Nice clear night gave a better opportunity to test the mono Infinity.  Impressive!  Seems to work OK with the Synta goto AZ drive on my 10" Dob.  I was able to focus better, easier with dimmer stars.  5 sec exposure seems optimum, 10 sec gave a bit more blur.  See attached captures.  Hmm...seems I can only attach one picture and it has to be small....

[scpanish]

I also got a very nice shot of the veil nebula, or a piece of it since the field of view is too small.  Unfortunately I didn't save it as a .jpg, which is the only format small enough to work for this forum.

Overall, after two evenings of use, I am very pleased with the goto Dob / mono Infinity combination.  5 sec exposure seems optimal for sharpness vs sensitivity for this F4.7 scope.  The color version would have perhaps 1/2 the sensitivity.  The reject feature does a good job for improving image quality in the stacking.

Support folks, can or will the software support a color wheel for the mono camera?  That would be nice. 

I will report further when I get to try a reducer and other types of targets, and I'll know to save .jpg files for posting.

STeve

[scpanish]

I've now had 6 sessions with the Infinity mono and can report further.

The Synta Dob drive is less accurate for objects that are high and for these the exposure seems best limited to 2 sec. or less.   This isn't much of a limitation since the sensitivity is so high, may be more of an issue with the one shot color.

The camera is very good for nebulae and clusters with nebulosity, the histogram stretches can really bring out the detail in the clouds.  Likewise for medium sized galaxies such as M51, and larger planetary nebulae such as C40 or M57.  Details such as central stars become very clear while invisible at the eyepiece.

However, globular clusters are not very rewarding, the resolution just isn't good enough to do all those stars justice, and achieving pinpoint focus is difficult with my cheap single-speed focuser.  I couldn't get a good image of M31 either, the brightness range was too large and any particular exposure will be correct for one area but not another.  So the core is invariably bloated when there is any detail visible in the arms. 

My .5X reducer won't work, requires more infocus than I can get.  I will try partially collapsing the tube.

Attaching picture of C40 planetary nebula.  It is just a small fuzzy blob in the eyepiece at 200X.

Steve