Atik 314L+ versus 414EX

[Scott]

I'm looking at one or the other and was wondering if anyone has had any experience with the new 414? I know it's early days but I'd be interested to hear any comments. the 414 is supposed to be more sensitive but I'm struggling to move past the 314L+. After all, it's certainly got the runs on the board hasn't it ?

[NickK]

I'm looking at one or the other and was wondering if anyone has had any experience with the new 414? I know it's early days but I'd be interested to hear any comments. the 414 is supposed to be more sensitive but I'm struggling to move past the 314L+. After all, it's certainly got the runs on the board hasn't it ?

I was looking at the sensitivity ratings and more importantly the sensitivity for narrowband - especially Ha.

I'm excited because I have a 414ex on it's way here - fingers crossed this week

[Scott]

I look forward to hearing what you think of it Nick. To be honest, I can't imagine Atik would let loose an inferior product onto the market. It's toocut-throat to take chances of upsetting the customers

[johnrt]

The 314l is a great camera, and you can pick them up for a great price used now, but the 414 will represent several years of advances in technology - enhanced QE, read noise and cooling on the chip. If I had the budget I know where my money would be going, but without knocking the 314l - is a cracking camera in it's own right.

[NickK]

I think the folks at ATIK know what they're doing .. but my personal preference is for smaller pixels to get the maximum out of images.. but the 414's sensitivity will be great

If it's a 30% increase in sensitivity.. that's an extra hour of photons for the price of a three hour session..

[NickK]

It's arrived :D

Just checked it works with the new ATIK OS X TheSkyPlugin - bingo.. worked first time

[NickK]

I've just been playing with a 300mm F4 canon FD lens with the 414EX inside - first impressions are that it's a fair bit more sensitive. Will need to get it out on the back of the Pentax for more objective testing

[pete_l]

I think the folks at ATIK know what they're doing .. but my personal preference is for smaller pixels to get the maximum out of images.. but the 414's sensitivity will be great

If it's a 30% increase in sensitivity.. that's an extra hour of photons for the price of a three hour session..

The figures for the two CCDs are

ICX285: peak QE = 55%

ICX825: peak QE = 73%

if you're doing narrow-band imaging at the point of peak QE, then  a "flux" of 100 photons per second per pixel lighting up the sensors, an ICX285 camera would need 18.2 seconds to get 1,000 photons in a pixel (1000 / 0.55 = 1818 photons needed)

An ICX825 based camera would get 1,000 photons in a pixel in 13.7 seconds (1000 / 0.73).

So the ICX825 based camera will "see" the same number of photons per pixel in ¾ of the time (13.7 / 18.2)  that an ICX285 camera would take.

If you're doing  mono imaging, then the relative sensitivity of the ICX825 looks from the graphs to be about 49,000 compared with the ICX285 total sensitivity of 26,500 - so across the whole visual spectrum the camera would collect nearly 85% more photons than the ICX285, so your images will get to the same brightness in about 54% of the time - just over 1 hour instead of 2. And for Hα, that extra 60% sensitivity gets you the same brightness in 60% of the time: 35 minutes instead of an hour .

For RBG, it's more complicated as it depends on the relative "area under the curve" for the various filters you're using.

The ICX825 has some other advantages too. It has larger wells, so can collect more photons before saturating a pixel. It's also less noisy (lower dark noise) and has its sensitivity peak a little further towards the Hα and generally a flatter, broader peak efficiency range.

[NickK]

I just can't wait for the clouds to vamoosh!

Yup - it would mean a new LRGB calibration against a known star type as the sensor characteristics have changed. It should be interesting for Ha solar too.. once I get the spectrograph back on track!

[edjrgibbs]

My 414EX arrived yesterday! Looks to be clear on Saturday so I'll post some images if I get anything. Just to say, it's a thing of beauty. Lovely build quality.

[Stardust]

very interested to see what this camera can do, will keep an eye out for your images.

[Scott]

thanks for taking the time to post everyone, it certainly seems to be moving off the shelves anyway. I look forward to seeing some results when these pesky clouds do one

[NickK]

thanks for taking the time to post everyone, it certainly seems to be moving off the shelves anyway. I look forward to seeing some results when these pesky clouds do one

Forecast to be clear tonight ... so I'll be prepping early for a bash and a comparison against the 383L.. 

[NickK]

Well so far so good.. I thought I'd made a mess of the filter wheel code in the plugin.. but no it appears one usb cable is dead.. next.. lol.

I've taken a a moon shot so far - low down but at 0.02 seconds with the ExampleApp whilst focusing. No stretching just capture of a single sub. IIRC temps were about -10degC but it was all still cooling down. Atmosphere was churning like nobodies business. 

I have 20 more and will do a stack at some point.

One thing I do notice is the the slightly different scale of between the 383L (5.45um, 3362x2572 iirc) and the 414EX (~6.5um 1391x1039).

Still attempting to locate the horse head from last time for the 383L comparison. very difficult as it is in the direction of a street light :/

[Scott]

thanks nick, will you be taking it to sglx?

[NickK]

Err.. holy cows... m42 with 30 second exposures...

A sub FITS for your pleasure: 414EX.00000051.A.fit

[NickK]

thanks nick, will you be taking it to sglx?

I certainly will! 

[Scott]

I certainly will! 

good to hear, I think it's the one I'll be going for so I'll be picking your brain

[NickK]

Just noted that the focus wasn't great on that sub.. just taking a 5 minute sub after refocusing.. then onto the horse head and flame.

[Scott]

It's a good job you're not in stoke mate. you'd be imaging clouds

[NickK]

Comparison time

Temperature for both is -15 degC, no guiding and manual PA. Both at 670mm with the Pentax 105SDP.

414EX 500 second sub of the flame: 414EX.00000075.A.fit

383L 500 second sub of the flame & horsehead: 383L.00000040.A.fit

Dang that 383's sensor size but .. that 414 has a lead in the sensitivity! ... I still love the 383L even with it's shutter.. and I think this is going to be good for bright targets an still give DSOs a good innings... 

Filters in place for both: UV/IR cut, Neodymium and then UV/IR as L filter.. what is instantly apparent is that the sky background light polution is being detected as a faster rate.. I'll try a 35nm Ha filter in a bit..

[NickK]

Counting down on the 35nm Ha.. 500 seconds should help cut out the LP and see what we can get out of the 414..

Actually I forgot to mention, something did strike me whilst finding, focusing and setting up.

The 383L is easy to find a bright target. The sheer size gives you a massive error margin but it needs to have 5 second subs and possibly you may see the brighter stars. Things take a little longer in focusing due to the shutter but with preview mode and subframing, the download is brought down from 12 seconds to near realtime - enough for focusing manually. Having used the 11000M then 12 seconds seems quite reasonable.. IIRC the 11000M was something like 22 seconds for the full frame (but again preview, sub frame and binning work wonders).

The 414EX is way way easier to find targets.. the flame was detectable with 3 second subs with the LCD screen outside. However I forgot to realign the red dot finder so it made hunting for targets a right pain! Only once I'd found M42 and then factored in the shift due to sensor size etc, did I get to the flame. The download of the small image size is fast.. 

It's a pity my MBP's GPU is as dead as a dodo.. attempting to use Mount/ExampleApp/TheSkyX that cause a GPU switch has left me with 3 hangs this evening.. the mac mini is quietly capturing, running it all.. whilst sat out in it's little box all warm and snug.

And.. here for comparison is a 500 second 35nm Ha sub: Flame_500s_35nmHa.fit

[Krzychoo226]

Hmm.. Can you provide some bias frames (10?), dark frame and some flats?

[edjrgibbs]

Imaging run set up, filters in place came back an hour later to find that I'd hit the meridian ARGHHH!! So only the finder sub at 60 seconds (ambient, 3 degrees or so) and a 300s sub (-10). All just through the IR Cut filter.  Either way its pretty darn sensitive.

[edjrgibbs]

Sorry, should have mentioned, taken through an Equinox 66, HEQ5 mount and ST80/QHY5 finder setup. All taken with APT.