QSI RS8.2 - First Light

[zakky2k]

Hi All,

    I recently purchased this camera based primarily on the company's solid reputation in this and other forums, however I had noticed that the new RS line was available with some additional features that I admit probably won’t be immediately useful (at least for amateur astronomers). 

After including in my order the optional 8 position CFW with IGP port (QSI's Integrated Guider Port, a built-in OAG), it effectively becomes a 683-wsg8 with the only exception as far as I know that the camera comes with a fused-quartz window protecting the CCD. 

Additionally I took the wider nose-piece and the Canon lens adapter. Unfortunately due my limited time I was not able to try out the lens adapter. It does require the face-plate to be exchanged with the standard, non-IGP face-plate in order to reach focus, only a 5 minute job in itself but something on my to-do list next time.

The reputation for QSI's quality is well deserved in my opinion; everything arriving securely packed in its own, high-quality pelican case. 

Within minutes I had the drivers installed and was able to control the camera and filter wheel through Maxim.

I decided to leave the standard 2" nose piece on the spare face-plate (the standard, non-IGP version) and attached the slightly larger nose piece to the IGP face-plate.

This is my first time using a dedicated CCD, so full-frame, low noise, high sensitivity over a wide spectrum and being able to set the temperature were all big firsts for me. I settled with -25C as the ambient was hovering around 0C, and only required approximately 35% cooler power to maintain. Being able to take re-usable darks at a specific temperature at any time proved to be a big time-saver.

It was also my first time auto-guiding, and following the simple focusing procedures provided by QSI I was up and running capturing data within an hour. 

The weather was naturally atrocious for the following week, but managed to get around 5 clear nights throughout December.

For anyone interested, my favorite images are in the album below:

http://stargazerslounge.com/gallery/album/2912-december-2013/

Comments, questions and even mild criticism welcome ;-)

Clear skies,

Zak

[narrowbandpaul]

Hi Zak,

Interesting choice of camera. Why the choice of the RS version over the 683? Are you planning on doing any kind of science with it? As for cooling the lower the better. I stick with the cooler at about 80% ish. I have never had any issues with this.

The QSI is a good camera and the 8300 a good sensor. You'll enjoy working with it.

Paul

[Sam]

Zak, I have the QSI 683wsg and am equally impressed. I've had it down to -25 when the ambient has been up around 15 degrees so the cooling is certainly very effective.

[zakky2k]

Hi Paul,

    I have to admit that the additional features of the RS series probably will not be immediately useful to me, however after years of reading reviews and opinions of the available CCD products, I had already made my choice for the QSI 683 series (built-in OAG, 8pos filter wheel and largest chip with 1.25" or 31mm filters were the key factors for me, combined with seemingly constant praise for the camera's build and image quality).

It was only when I got to the point of ordering the camera I noticed the RS range, and after comparing the features and discussing with the sales staff it seemed to me like a more future-proof investment, as it would still perform all the functions I needed, offer the potential and flexibility for other applications and *could* be easier to re-sell if I ever wanted to due to a wider range of potential buyers.

By the way, I've just noticed that QSI now offer a 9mp version with the latest Sony CCD. 70% peak sensitivity, so much for my future proof theory!

Ah, such is life in this hobby of ours...

Zak

[zakky2k]

Zak, I have the QSI 683wsg and am equally impressed. I've had it down to -25 when the ambient has been up around 15 degrees so the cooling is certainly very effective.

Hi Sam,

I was impressed by how fast the temperature stabilized! It's my first time using a cooled CCD and ambient was low anyway so that might be expected, but nice none the less. After initializing the camera the coolers had stabilized by the time the telescope had slewed to my target!

Obviously I could have pushed the cooling further but when I read about the diminishing rate of returns cooling has on noise, -25C seemed like a reasonable number. My plan is to maintain the same cooling throughout the year (simplifying calibration and processing).

So I'm hoping -25C will also be reachable during the hotter months (15-20C at night). It's going to be tight, especially if we have another heat wave in August, but for the rest of the year it will be easily achievable.

Then there's always the option to maintain two sets of calibration files, (i.e. cold + hot) or alternatively the water-cooling add-on.

The advantage of W/C would be to sustain a lower temperature throughout the year (i.e -35C), but given the low noise currently present I'd need to spend more time researching if this would be wise choice.

Zak

[Sam]

Last night I had my camera at -25 and the ambient was just under 20. The camera was 60% of effort so I think -25 is a safe bet all year round.

[Physopto]

The 690 chip is only about half the actual size of the 683 chip. So your image will be half the size when used with the same telescope set up! OK if you want a higher mag image but useless if you want to get the same area of star formation.

[Physopto]

As an addendum to my last post, the fused quartz window should be a lot stronger than the standard window. Also fused quartz if properly heat treated, i.e. cooled down slowly to stress relieve internally, will transmit ultraviolet light probably below 200nm without affecting polarisation of the light.

Derek

[zakky2k]

As an addendum to my last post, the fused quartz window should be a lot stronger than the standard window. Also fused quartz if properly heat treated, i.e. cooled down slowly to stress relieve internally, will transmit ultraviolet light probably below 200nm without affecting polarisation of the light.

Derek

Good to know! I've been considering some UV work for planetary imaging. It seems Venus starts showing some decent details at these wavelengths, but I'd really need to move up to bigger diameters/longer focal lengths to get the resolution.

This comes back to your previous point about sensor size, there is always some compromise to be made! However I'm still satisfied with my choice and the camera performs great, I just wish there was a few more clear nights! 

[Physopto]

Good to know! I've been considering some UV work for planetary imaging. It seems Venus starts showing some decent details at these wavelengths, but I'd really need to move up to bigger diameters/longer focal lengths to get the resolution.

This comes back to your previous point about sensor size, there is always some compromise to be made! However I'm still satisfied with my choice and the camera performs great, I just wish there was a few more clear nights! 

Hi Zak,

 You have not said what kind of telescope you are going to use.

The QSI RS CCD is not really intended for anything other than research.  To do any type of UV astronomy, any other optical component in the light path before the CCD must also be of the  stress relieved Fused Quartz type.  This includes the filters as well (some quartz type are made by Astrodon).  Lenses  used in focusers are another matter, I've never heard of any.

The Fused Quartz that is used is of two basic types, Type "A" and "B". Type "A" is the best. If not properly heat treated e.g. stress relieved on cooling it will exhibit birefringence. Birefringence means that the light can follow two separate paths through the component. It is to do with the crystal structure of the glass. The two paths are because there are two distinct refractive indexes in the material orthogonal to each other. The two light rays are called the Ordinary and Extraordinary rays one of which will travel at a slower speed than the other. Thus the two rays will normally end up out of phase when leaving the substrate (lens/window). Proper stress relief removes this problem. The reason I mention this is because it adds a great deal of expense to any lens/window. The benefit to you with the camera you have bought, is strength and also there should be a total lack of induced polarisation artifacts caused by the CCD window.

In short it is a beautiful camera.

And don't we all wish for clear nights!

Good luck in your astro endeavors.

Regards,

 Derek