Lodestar x2 color x Atik Infinity

[Hibou]

3 hours ago, mystyco said:

The images that I posted, to me look absolutely amazing...  My concern are the faint objects, even M81 which is quite large looked like a grainy tv screen...

... what I really didn't liked at all was the chip size ...

I thought your images looked amazing too; almost enough to tempt me to get into colour astronomy :-) The Atik site has no Infinity images of M81, but it does have quite a few with the equivalent but older, less sensitive 285 chip in the 314L+ and they too look great to an ingénue like me. Of course that is a cooled camera, there's not much information on the exposure conditions, and the best one is with a mono chip and filters, far from EAA. As stash_old said, EAA is a choice. And I suppose that if you really didn't like the 825 chip size, you would have liked the smaller 829 in the lodestar even less :-) 

[mystyco]

I have a theory. I think that after 2-3 targets the camera gets super noisy and you won't be able to do quality images until it cools down. My first images always look great, not sure if it's because I've been practicing in easy, big and bright targets, but I have to confirm this. The camera drains my power tank pretty fast, so I can only to try again tomorrow. My first target will be a faint DSO.

Regarding the chip size, yeah, I would definitely not like a chip smaller than this.

And from today, running man nebula (again) no image editing other than noise reduction. 300 seconds, 20'' each.

[Carl Reade]

Hi I found an M81 from my first outing. This was using my usual setup with LP filter so guessing F6? This was with the first version software which had no colour adjustment settings. Bearing in mind this is with my gear which aint fast  I have taken shots of M81 with other cameras and found it very difficult if at all possible to get the outer rim of the galaxy. I myself still need to get a good play with different exposures and level settings if the weather would play nice.

Even looking at photos with 14 hours of "data" they are not spectacular imho.

To coin a phrase "the outer rim can be very dim"

 

[DoctorD]

Hi 

For comparison (if that's possible  ) here's my M81 from February - Lodestar-C, C8 F3.3 reducer at about F3.4, no filters, Starlight Live.

 

The "black" fleck's are hot pixels removed using live dark frame subtraction.

Taken from my Red Zone light polluted garden just West of Bradford.

I used one of the non linear display modes (0.5^2 I think) which reduces the chances of burning out the core.

Note pretty much no colour in the image.

HTH

 

Paul

[Martin Meredith]

Again, for comparison (and to show what is possible from a darker site, SQM 20.0 on this occasion, though not a really dark site!), this is with the Lodestar X2 mono in the same stack/exposure size as Paul's. I used arcsinh to bring out the details. This with an 8" f4 Newt mounted in alt-az, no filters. Ignore the dust bunnies...

Any more EAA M81s out there?

Martin

[DoctorD]

Hi Martin

I do like your round stars - the F3.3 reduced SCT shows significant distortion - I've tried playing with the reducer spacing and think I need to go back to 10mm spacer plus adapters which seems to give me about F3.5 and less distortion.

I'm also envious of your darker skies too!

CS

Paul

 

[Astrojedi]

2 hours ago, Martin Meredith said:

Again, for comparison (and to show what is possible from a darker site, SQM 20.0 on this occasion, though not a really dark site!), this is with the Lodestar X2 mono in the same stack/exposure size as Paul's. I used arcsinh to bring out the details. This with an 8" f4 Newt mounted in alt-az, no filters. Ignore the dust bunnies...

Any more EAA M81s out there?

Martin

Martin,

That is just incredible detail. Probably one of the best M81 I have seen in short exposures..

Hiten

[Astrojedi]

And here is the M81 using the Ultrastar mono from my heavily light polluted location (red/white zone) using a C8. Total exposure time is ~2.5 minutes (15x10s)

Not my best capture of the M81 but the only one I could find...

 

 

[Carl Reade]

Well off subject now?

[Astrojedi]

To bring it back on topic. Here is one using the Lodestar X2 color using asrcsinh non linear stretch. Again not the best example as it was shot through a light layer of clouds. But should provide some value in terms of comparison.

 

[DoctorD]

Hi Hiten

You seem to be able to pull out much more detail than I can using similar equipment in a similarly light polluted area - well done!

I wonder where or not your skies are clearer despite the light pollution - I think I may suffer from higher humidity levels which may exacerbate the local light pollution.

My image looks much more like your image taken through thin clouds.

CS

Paul

[Astrojedi]

Thanks Paul.

Note that we also typically have high humidity as I am just ~5 miles from the coast but we do also get some dry days (when we have a high pressure system over land) which helps.

But the real reason the image looks like that is because I had dew on the corrector plate (I only found out later). The dew was not obvious/visible as these were still micro droplets but sufficient to impact capture.

The thing is that on humid/high moisture days you get a double whammy as transparency is low but also moisture collects more quickly on optics. I highly recommend keeping the dew heater running even if there isn't sufficient accumulation to make the dew visible/obvious.

The other critical factors that impact detail are accurate focus and collimation of the scope. I spend quite a bit of time getting accurate focus at the start of a session and then recheck every couple of hours.

I also noticed in your signature that you use the original Lodestar C. The Lodestar C has relatively high read noise vs. X2 Lodestars which means you will lose subtle detail in short exposures. Not sure if this applies to you but in my experience lower read noise cameras produce better detail in the same exposure time.

[DoctorD]

Hi Hiten

I tend to leave my dew heater on all the time as I cannot control this remotely. 

I use a bahnitov mask for focusing, but perhaps I should try using a dimmer star. 

I rarely check collimation - do you do this by eye or with your camera?

I had a go recently when we had a partly cloudy night, used a defocused star and tried to centre the hole in the donut using the camera with no reducer. I was unable to see any diffraction pattern using the Lodestar .

Interesting comment on read noise - I had not realised that the X2 was significantly different from the original, thought it was primarily better sensitivity. 

CS

 

Paul

[HiloDon]

Hi Doc,

I downloaded your M81 image and opened it in Nebulosity 3.  Increasing the white level brought out a lot of detail similar to Hiten's without blowing out the center. I think both of you were dealing with moisture issues that caused a lightening of the dark sky around the object.  It's always a balance adjusting the white black and contrast to bring out the faint details and still keep the background sky dark.  Moisture on the lens or in the astmosphere makes it even more difficult.

I think the OP may be facing the same problems.  The color 825 sensor is pretty noisy when imaging dimmer objects.  Atmospheric conditions can make it worse.  As I indicated in earlier posts, the 825c sensor works best with fast optics and dark skies.  Extensive stacking will also help.  I doubt that it's the sensor temperature that's causing his problem.  I have not seen that in my experience with the Ultrastar.

Don

[Astrojedi]

Paul,

Read noise plays a critical role in determining sensitivity of the camera. The other factor being Quantum Efficiency of the sensor. Even with the same QE a camera with lower read noise will require shorter exposures to bring out more faint detail (longer exposures and stacking compensate but both incur a time penalty).

Hiten

[mystyco]

1 hour ago, HiloDon said:

Hi Doc,

I downloaded your M81 image and opened it in Nebulosity 3.  Increasing the white level brought out a lot of detail similar to Hiten's without blowing out the center. I think both of you were dealing with moisture issues that caused a lightening. Moisture on the lens or in the astmosphere makes it even more difficult.

I think the OP may be facing the same problems.  The color 825 sensor is pretty noisy when imaging dimmer objects.  Atmospheric conditions can make it worse.  As I indicated in earlier posts, the 825c sensor works best with fast optics and dark skies.  Extensive stacking will also help.  I doubt that it's the sensor temperature that's causing his problem.  I have not seen that in my experience with the Ultrastar.

Don

Don,

thanks for this tip. I have a dew heater but I would need another power tank to connect it since the Atik needs power as well. And in 3 hours my power tank gets empty. It used to last for at least a week.

I'll have to image a faint target in the beginning of my next session and make a note of my humidity level. Then after a hour or so, I'll image the same target again to compare. But I believe you are right, faint targets are not that good for this chip, and that disappoints me a bit, specially for the price of this camera. But I still need a week or so of tests because my first image was the M82 and the level of detail was impressive. Even the supernova was clearly visible.

Another thing that I've noticed with this camera is that I can't do exposures over 20" or I'll get star trails. With my DSLR I can go up to 60 seconds. In most cases, 40 seconds. Not sure exactly why. Probably a new mount is needed, but I don't want to go bankrupt with this hobby.

thanks.

 

[HiloDon]

I think M82 is a fairly bright object compared to the faint arms of M81.  Below is an image I captured recently with both in the FOV showing their relative brightness.  To get the faint arms of M81 I had to blow out almost the entire M82.  This was the Ultrastar with the same 825 sensor as your Infinity.  The skies were perfect and I used a C6 with Hyperstar.  290mm focal length at a fast F1.9.  Exposure was only 15 seconds with five stacks.

Your DSLR will have a much larger FOV than your Infinity using the same optics.  That may be the reason you get star trails with one and not the other.

Don

[mystyco]

Black Eye Galaxy (M64)

240 seconds (15'' each exposure). Since it looks like this camera limits me to 20'' exposures, I wonder if a focal reducer would make my f/5 newtonian faster? Any idea of what kind of reducer I should get?

Thanks!

[mystyco]

Elliptical galaxy M87 emitting a relativistic jet from the black hole. 240 seconds, 20'' each exposure. I still can't believe I captured this.

[Astrojedi]

Great capture. The jet is very bright and actually shows up better in shorter exposures. I would try using 15s exposures or using a less aggressive stretch for even better results. 

[mystyco]

6 hours ago, Astrojedi said:

Great capture. The jet is very bright and actually shows up better in shorter exposures. I would try using 15s exposures or using a less aggressive stretch for even better results. 

Thanks mate! I can't compare it with the one you did, but I was definitely surprised I could capture such a tiny detail. I tried a few months ago (spent a full night) and couldn't get anything. I'll try again with shorter exposures as you suggested, but I'm considering upgrading my mount, as I think that I'm missing the full potential of this ccd.

[DonBoy]

Here is M81 I took while learning AstroToaster with the Atik 414EX I had on loan.

 

This was the broadcast image with no post processing.

Don

 

 

 

[aparker]

Another M81 example - from last night.  Red/White zone (heavily light polluted) metro Boston, C8 @ 1360 mm EFL, no LP filter, Ultrastar.  I'm eagerly anticipating pixel binning in SLL v3, as this setup is way oversampled at under 1 arcsec/pixel.  2x2 or even 3x3 binning would not hurt detail given the seeing I usually have, and should crank the sensitivity greatly.

[Hibou]

On 2/26/2016 at 17:06, Astrojedi said:

You are implying that the Atik Infinity Color will 'win for intensity' due to its larger size as you can bin.

Lets get the facts straight...

1. You cannot bin the Infinity in hardware/charge domain and keep color

2. Binning in software does nothing for sensitivity or SNR yet you brought it up in defending your point.

3. Unbinned the Color Infinity and Ultrastars require long total exposures at slower f ratios. In my option these are best used at F2.

Looks like we are in agreement now.

Astrojedi may be interested to see that Atik now have an option for colour software binning in their Infinity stacking software. Software binning is not quite as good as hardware binning of the CCD charge - it's more like stacking. Yes, my original point was that bigger chips will always win for intensity, if you can adjust your focal length to give the same FOV, and even if the pixels are then too small, you can always bin to make them "larger" to collect more light. Astrojedi argued that hardware (charge) binning was not possible for colour CCDs, and appeared to dismiss software binning. Glad we are in agreement now that the facts are straight :-)

BTW, my favourite chip is now the 1" Sony monochrome CCD (Atik 460EX and fast readout Atik VS60). It's the biggest CCD Sony make, with great sensitivity and exceptionally low noise. Bigger is better.