ASI174 any good for deep sky?

[Space Cowboy]

Anyone tried the new ASI 174 for deep sky imaging? Think I'm correct in thinking it does long exposures? Just wondering if I could sell all my cams and buy this to image planets,solar, lunar and DSO?

[rwg]

Hi Stuart,

I have the 174MC and it's OK for deep sky - some amp glow that needs to be taken out with darks, but the noise isn't too bad. I have taken usable 4 minute subs with it. I expect the MM would be better as the thermal noise tends to be less noticeable in monochrome cameras.

I did an M42 and a horsehead earlier in the year to test out the camera. They are on the ZWO facebook page (https://www.facebook.com/ZwoDesignAstronomyCameras?fref=ts) - scroll down to the 16th Feb. They are a bit noisy, but really that was just a lack of total exposure time.

cheers,

Robin

[JamesF]

Would you be able to reach the necessary focal lengths easily enough for planetary, Stuart?  I imagine people are going to be looking for f/30 to f/35-ish or even beyond with the ASI174 (I think that's where Darryl is headed) and that's got to be a fair stretch with the 250P?

James

[riklaunim]

Would you be able to reach the necessary focal lengths easily enough for planetary, Stuart?  I imagine people are going to be looking for f/30 to f/35-ish or even beyond with the ASI174 (I think that's where Darryl is headed) and that's got to be a fair stretch with the 250P?

Pixel size again? I rarely used f/30 with 5.6 pixels in old/new DMK, and mostly sticked to f/20-25. There is no problem with getting a Barlow that would provide you desired focal length increase, even more than 5x. And note that people did use Lumenera or even old SBIG cameras with bigger pixels (20x20 in SBIG ST-9 )

[Space Cowboy]

Thanks Robin that's a pretty impressive m42 shot! This cam will be far.more sensitive than my canon 1000D.

No worries James my 5x power mate has been crying out for larger pixels since I stopped using the DFK ;-)

Thanks Rik!

I guess my question now is has anyone used the 174 with a Coronado PST?

[riklaunim]

IMX works nicely with solar H-alpha.

[JamesF]

No worries James my 5x power mate has been crying out for larger pixels since I stopped using the DFK ;-)

The 5x Powermate can give you more power with an extension too, so there should be some flexibility there if you do want to push the focal length up a bit.

James

[JamesF]

I guess my question now is has anyone used the 174 with a Coronado PST?

Meant to add... There were a lot of people keen to use this camera for PST imaging when it was released.  The sensor is large enough not to need mosaics which I know quite a few would consider a big plus, and if you do want to up the focal length there's a lot of sensor to play with.

Probably the most significant limitation is the aperture for the final filter which looks very tight relative to the size of the light cone.  I made a new fitting for my PST to allow that filter to be positioned right in front of the optical window on my 120MM.  The "nose" is longer on the 174 so I'll have to look to see if it needs at bit more work in the lathe.

James

[Space Cowboy]

Getting the full disk without mosaics is the main appeal of this camera James. Interesting what you say about the nose length and how that could effect things. I will have a sniff around the net and see if there are any images out there with this combination.

[JamesF]

Is your PST modded Stuart, or as it came out of the box?

This is what I did for my ASI120: http://stargazerslounge.com/topic/223721-my-latest-pst-bf5-positioning-mod/

Then I got a bit carried away and made one for the 314L+, too: http://stargazerslounge.com/topic/224240-pst-filter-mod-for-atik-314l/

Having checked it appears that although the 2" nose on the 174 is longer than the 120, internally the M42 threaded "well" looks the same depth on both so I think I should be ok.

According to ZWO's drawings however, the sensor in the 174 is 5mm further back from the front of the nose compared with the 120.  That could be awkward for getting focus with the stock PST.  If so something like a 1.5x barlow might push the focal plane out far enough whilst leaving an image that still fits in one frame?

James

[Space Cowboy]

My PST is unmodded James. That's some very impressive work you've done! The only cam I've used with the Coronado is the Qhy5l-ii which drops well inside the holder so very different to the zwo cams.

To be honest I'm not too keen on modding scopes to this degree so hopefully are are right about a 1.5x Barlow doing the job.