canon rumors FORUM

Rumors => EOS Bodies => Topic started by: Simdub on April 03, 2012, 11:46:05 AM

Title: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: Simdub on April 03, 2012, 11:46:05 AM
Canon Japan has just released the first samples from the new Canon EOS 60Da.

They used a φ115mm ED Astronomical telescope and images are modified by DPP. Here they are:

(http://web.canon.jp/imaging/eosd/samples/eos60da/img/002.jpg)
M42 Orion nebula

(http://web.canon.jp/imaging/eosd/samples/eos60da/img/003.jpg)
M45 Pleiades

(http://web.canon.jp/imaging/eosd/samples/eos60da/img/001.jpg)
M31 Andromeda galaxy

They also give a comparaison shot with the 60D (non-a):

(http://web.canon.jp/imaging/eosd/samples/eos60da/img/img_eos60d.jpg) (http://web.canon.jp/imaging/eosd/samples/eos60da/img/img_eos60da.jpg)
60D                                                                                          60Da

Here is the link to the official Japan Canon website: http://web.canon.jp/imaging/eosd/samples/eos60da/ (http://web.canon.jp/imaging/eosd/samples/eos60da/)

What do you think of these samples?
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: Tijn on April 03, 2012, 11:53:23 AM
They look like black clipping was not done or done poorly, but then again I'm not familiar with how astronomy photographs are supposed to look... Might just be the nebulas, but to me it looks hazy.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: Marsu42 on April 03, 2012, 02:05:43 PM
They look like black clipping was not done or done poorly, but then again I'm not familiar with how astronomy photographs are supposed to look... Might just be the nebulas, but to me it looks hazy.

Maybe the 60da shots aren't supposed to be comparable to the Hubble space telescope :-p .. and if you'd apply black clipping, you'd saw off nebula detail - I'd say a little more shadow gammy curve adjustment would be in order.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: daveswan on April 03, 2012, 03:31:47 PM
From the Japanese site it looks as if they just took single shots and processed in DPP, instead of a set of subs and stacking in DSS (Which is free).

I can see the improvement in the H-alpha but it's still not the best advert. Why they couldn't have fitted a square cut-off 400-700nm filter beats me, after all Baader and Astronomik do.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: kirispupis on April 03, 2012, 03:58:50 PM
Just curious, I know almost nothing about astrophotography, but how does the 60Da compare to the sensors that cost tens of thousands of $ that many astrophotography nuts use?  I am mainly curious to know what the difference is.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: JerryKnight on April 03, 2012, 04:16:10 PM
Just curious, I know almost nothing about astrophotography, but how does the 60Da compare to the sensors that cost tens of thousands of $ that many astrophotography nuts use?  I am mainly curious to know what the difference is.

I don't know much more than you, but I'm pretty sure that high-end astronomy CCDs are actively cooled and have no color filters (ie. Bayer pattern). You take multiple exposures with multiple filters (not necessarily RGB). The cooling cuts down on sensor noise, and the lack of built-in color filters makes the effective resolution higher, and I'm pretty sure they have no IR/UV filters unless you use your own, so you can photograph any range of light spectrum you want.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: lol on April 03, 2012, 04:55:06 PM
I can see the improvement in the H-alpha but it's still not the best advert. Why they couldn't have fitted a square cut-off 400-700nm filter beats me, after all Baader and Astronomik do.
Maybe I missed it, have Canon said what the 60Da filter response is somewhere?

Just curious, I know almost nothing about astrophotography, but how does the 60Da compare to the sensors that cost tens of thousands of $ that many astrophotography nuts use?  I am mainly curious to know what the difference is.
In short, the astro CCDs are optimised for high quantum sensitivity and low noise, helped out by active cooling on them. They are certainly "better", but at what cost...
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: riogrande100 on April 03, 2012, 05:42:34 PM
I actually came to photography from Astrophotography! And for years the community chose Canon as its DSLR of choice as it seemed to work better for long exposures and less noise. Canon identified this and released the 20Da.

Essentially since the 20Da was retired many astrophotographers have been hacking DSLR and removing the UV filter manually to increase the colors in HA.

The haze captured in the photos are called nebulosity and something astrotogs look for as it shows the feint dust clouds! However these pics with the exception of M42 have not been tweaked for contrast!

Whilst CCD cameras are used for monochrome images, the larger sensors are high MPX means higher resolution pics!

A lot of CCD cameras are cooled as when open for long exposure the sensor heats up and generates more noise! Yes temperature of the sensor has an impact on noise performance wonder how many people factor that into their noise tests!

However a Full Frame CCD sensor puck is in the 1000s and can only be used for astro! now by removing the UV filter it does make the camera almost unusable in the day as all images capture more Colors in the infrared!

But i am happy Canon released this camera should have done so sooner!





Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: emag on April 03, 2012, 05:43:34 PM
Fairly clean images for 8 minute exposures at ISO 1600.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: dr croubie on April 03, 2012, 05:43:39 PM
So, ... they've just introduced a Canon camera with more red?  :o
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: epsiloneri on April 03, 2012, 07:42:34 PM
Just curious, I know almost nothing about astrophotography, but how does the 60Da compare to the sensors that cost tens of thousands of $ that many astrophotography nuts use?  I am mainly curious to know what the difference is.
To begin with, back-lit CCDs are way more sensitive (no Bayer filter + higher QE => up to 5 times more sensitive for a given wavelength) but as important is that astronomical CCDs almost always are actively cooled to reduce the dark current. Dark current can easily be the most signicant source of noise for very faint sources that require long exposures. An additional problem is that the dark current fills up the electron well with time, reducing the dynamic range unless the photo-sites are periodically reset by making multiple shorter exposures, but the problem with multiple exposures is that each readout adds noise.

The advantage of the 60Da on the other hand is that you get all three colours simultaneosly, and at 18 Mpix, for a low cost. And you can easily use it with EOS lenses, something that can be a bit involved for astrophotography-dedicated CCDs.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: FunPhotons on April 03, 2012, 09:01:59 PM
They look very good for DSLR astro photos. I'm not much into DSLR astrophotography, because the captures look blobby, low res with washed out colors compared to a good CCD with color wheels. But its an easy way to get a picture without having to spend $10k and mess with the filters. If you're into it then this looks like a step up.

Makes me wonder, by the time you get a decent mount, 'scope, etc, and spend the time to set up and the hour(s) to take the shot, why bother putting a substandard imager on there?
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: emag on April 03, 2012, 10:39:40 PM
Valid points re: cooled CCD/filters vs. DSLR.  The truly spectacular images are taken with such equipment (cooled CCD), there are always better ways to image faint fuzzies than what any one of us has or likely will ever have.  A DSLR is a capable imager that allows us to photograph things we can't see and doesn't require hours of accumulated imaging time followed by even more hours combining LRGB, Ha, OIII, S2 or whatever colors.  I do a lot of public outreach work and stargazes for Scouts camped in the dark country an hour away.  A DSLR with a 300L piggybacked on a small scope is the perfect combo - they can look through the scope and see (I believe the technical term most often heard is) a fuzzy blob, wait a minute or so and then see the Lagoon in full color on the laptop or a monitor.  On those relatively few nights per year when weather, work and moon combine to permit a night of imaging, I can spend hours on two or three objects in the hopes of capturing something spectacular or capture a dozen or more objects in quality adequate to please me and not make it feel like work.  My concern with the 60Da is whether it is so much better than a modified T3i that the heftier price is worth it (to me, at least).  I'll let things shake out for a few months.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: nitsujwalker on April 03, 2012, 11:29:32 PM
They look like black clipping was not done or done poorly, but then again I'm not familiar with how astronomy photographs are supposed to look... Might just be the nebulas, but to me it looks hazy.

Maybe the 60da shots aren't supposed to be comparable to the Hubble space telescope :-p .. and if you'd apply black clipping, you'd saw off nebula detail - I'd say a little more shadow gammy curve adjustment would be in order.

I dunno, I just did slight clipping on the third photo..  Didn't lose anything really.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: Caps18 on April 04, 2012, 12:25:32 AM
From the Japanese site it looks as if they just took single shots and processed in DPP, instead of a set of subs and stacking in DSS (Which is free).

I can see the improvement in the H-alpha but it's still not the best advert. Why they couldn't have fitted a square cut-off 400-700nm filter beats me, after all Baader and Astronomik do.

I wonder why DPP can't do stacking...

I wonder if back-lighting or sensor cooling would help at all.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: nikkito on April 04, 2012, 12:55:57 AM
Well, usually almost every sample picture they upload needs some small levels & contrast adjustments. I understand they want to upload the pictures straight from the camera, but come on....  ::)
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: dr croubie on April 04, 2012, 12:56:05 AM
I wonder if back-lighting or sensor cooling would help at all.
I'm wondering why this isn't the 7Da instead.
Surely, we don't need 19AF points and 8fps for astro.
And the weather-sealing on the 7D probably makes the sensor heat-up faster. Or would the metal-body help with passive-cooling?
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: daveswan on April 04, 2012, 10:21:00 AM
From the Japanese site it looks as if they just took single shots and processed in DPP, instead of a set of subs and stacking in DSS (Which is free).

I can see the improvement in the H-alpha but it's still not the best advert. Why they couldn't have fitted a square cut-off 400-700nm filter beats me, after all Baader and Astronomik do.

I wonder why DPP can't do stacking...

I wonder if back-lighting or sensor cooling would help at all.

Because it's a basic raw converter for "ordinary" photos. Something like DSS is dedicated to stacking raw astrophotos and would be no good for "ordinary" photography. Tools for the job, pick the right one.


Only by removing the back and adding a Peltier cooler and fan, but then you'd lose the LCD.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: kdsand on April 04, 2012, 01:09:06 PM
I can't wait!
This will be perfect for my next vacation!

Have spacesuite will travel.
  ;)



Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: Axilrod on April 04, 2012, 01:28:41 PM
They look like black clipping was not done or done poorly, but then again I'm not familiar with how astronomy photographs are supposed to look... Might just be the nebulas, but to me it looks hazy.
Dude they're taking pictures of objects so far away it's hard to even comprehend the distance, I'd say they're pretty damn good for a $1400 camera.  But then again I'd like to know what kind of telescope they were shooting through...
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: kdsand on April 04, 2012, 01:32:08 PM
They look like black clipping was not done or done poorly, but then again I'm not familiar with how astronomy photographs are supposed to look... Might just be the nebulas, but to me it looks hazy.
Dude they're taking pictures of objects so far away it's hard to even comprehend the distance, I'd say they're pretty damn good for a $1400 camera.  But then again I'd like to know what kind of telescope they were shooting through...

The kit lens.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: BobSanderson on April 04, 2012, 02:13:58 PM
The photos posted here are amazing and beautiful. Thanks.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: mws on April 04, 2012, 03:37:40 PM
They look like black clipping was not done or done poorly, but then again I'm not familiar with how astronomy photographs are supposed to look... Might just be the nebulas, but to me it looks hazy.
Dude they're taking pictures of objects so far away it's hard to even comprehend the distance, I'd say they're pretty damn good for a $1400 camera.  But then again I'd like to know what kind of telescope they were shooting through...


5200mm f/14

http://www.popphoto.com/news/2010/01/canons-enormous-5200mm-f14-dslr-lens (http://www.popphoto.com/news/2010/01/canons-enormous-5200mm-f14-dslr-lens)

I honestly have no idea, but I wonder what you could do with that lense.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: Lee Jay on April 04, 2012, 03:48:15 PM
But then again I'd like to know what kind of telescope they were shooting through...

From the OP:

"They used a φ115mm ED Astronomical telescope..."

Maybe a Meade or Vixen?

Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: dstppy on April 04, 2012, 03:51:16 PM
I wonder if back-lighting or sensor cooling would help at all.
I'm wondering why this isn't the 7Da instead.
Surely, we don't need 19AF points and 8fps for astro.
And the weather-sealing on the 7D probably makes the sensor heat-up faster. Or would the metal-body help with passive-cooling?

Seriously . . . they coulda dinged people for $2k if that were the case . . .

My questions is, can we get some SMALLER images to compare?   :o
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: whwang on April 04, 2012, 09:57:43 PM
To begin with, back-lit CCDs are way more sensitive (no Bayer filter + higher QE => up to 5 times more sensitive for a given wavelength) but as important is that astronomical CCDs almost always are actively cooled to reduce the dark current. Dark current can easily be the most signicant source of noise for very faint sources that require long exposures. An additional problem is that the dark current fills up the electron well with time, reducing the dynamic range unless the photo-sites are periodically reset by making multiple shorter exposures, but the problem with multiple exposures is that each readout adds noise.

The advantage of the 60Da on the other hand is that you get all three colours simultaneosly, and at 18 Mpix, for a low cost. And you can easily use it with EOS lenses, something that can be a bit involved for astrophotography-dedicated CCDs.


Hi,

I happen to be an astronomical researcher and an astrophotographer who use Canon extensively.  Here are a few of my recent photos taken with a modified 5D2:
http://www3.asiaa.sinica.edu.tw/~whwang/gallery/picutres/M42_2010.html (http://www3.asiaa.sinica.edu.tw/~whwang/gallery/picutres/M42_2010.html)
http://www3.asiaa.sinica.edu.tw/~whwang/gallery/picutres/M101.htm (http://www3.asiaa.sinica.edu.tw/~whwang/gallery/picutres/M101.htm)
http://www3.asiaa.sinica.edu.tw/~whwang/gallery/picutres/rosette-2011.htm (http://www3.asiaa.sinica.edu.tw/~whwang/gallery/picutres/rosette-2011.htm)

I would like to add a few words to the topic on DSLR vs cooled astronomical monochrome CCDs.

As epsiloneri pointed out, a big advantage of astro mono CCDs is their high QE.  The fact they don't have Bayer filters allow them to adopt the LRGB color combination, in which they spend most of the time on L and only a little time on RGB. The L filter essentially uses the entire throughput range in the optical spectrum.  Coupled with the high QE of the sensors, this produces very high S/N and high resolution in a short amount of time.  This is proven to be an extremely efficient way of producing high quality color pictures, and DSLR just can't match this.  Even if DSLRs have similar QE as mono CCDs, it will still take a Bayer-style DSLR 2x (or even 3x) more exposure time to achieve the same quality. In my opinion, the biggest advantage of mono CCDs is their flexible filter usage, which allows for the very efficient LRGB and other possibilities.

Many people also think cooled CCDs are good because they are cooled and they have low noise.  Unfortunately, this is not correct.  First, recent DSLRs produced by Canon and Nikon all have LOWER noise comparing to CCDs from Kodak and Sony. Here I am talking about readout noise.  DSLRs' readout noise can be as low as 2-3 electrons rms per pixel (for example, 5D2 at ISO 1600 and 3200), but CCDs are still in the range of 7-10 (even > 10) electron per pixel. This is the same for dark current.  Recent Canon and Nikon CMOS chips have dark current that's MANY TIMES LOWER than that of Kodak/SONY CCD chips under the same temperature. The low temperature produced by the cooling system in those cooled CCDs help to reduce their dark current from being miserable to better than DSLRs, but not much better.  Plus, even when uncooled, recent DSLRs already have dark current that's comparable or even lower than sky photon rates in most astrophoto environments.  So dark current is no longer a limiting factor for the performance of DSLRs on astrophoto, as long as one subtract dark carefully, which is not difficult and doesn't take much time.

So, be happy with the Canon DSLRs you have.  They are great, maybe not up to the level of the best cooled CCDs, but not far behind too.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: kdsand on April 05, 2012, 01:43:26 AM
To begin with, back-lit CCDs are way more sensitive (no Bayer filter + higher QE => up to 5 times more sensitive for a given wavelength) but as important is that astronomical CCDs almost always are actively cooled to reduce the dark current. Dark current can easily be the most signicant source of noise for very faint sources that require long exposures. An additional problem is that the dark current fills up the electron well with time, reducing the dynamic range unless the photo-sites are periodically reset by making multiple shorter exposures, but the problem with multiple exposures is that each readout adds noise.

The advantage of the 60Da on the other hand is that you get all three colours simultaneosly, and at 18 Mpix, for a low cost. And you can easily use it with EOS lenses, something that can be a bit involved for astrophotography-dedicated CCDs.


Hi,

I happen to be an astronomical researcher and an astrophotographer who use Canon extensively.  Here are a few of my recent photos taken with a modified 5D2:
http://www3.asiaa.sinica.edu.tw/~whwang/gallery/picutres/M42_2010.html (http://www3.asiaa.sinica.edu.tw/~whwang/gallery/picutres/M42_2010.html)
http://www3.asiaa.sinica.edu.tw/~whwang/gallery/picutres/M101.htm (http://www3.asiaa.sinica.edu.tw/~whwang/gallery/picutres/M101.htm)
http://www3.asiaa.sinica.edu.tw/~whwang/gallery/picutres/rosette-2011.htm (http://www3.asiaa.sinica.edu.tw/~whwang/gallery/picutres/rosette-2011.htm)

I would like to add a few words to the topic on DSLR vs cooled astronomical monochrome CCDs.

As epsiloneri pointed out, a big advantage of astro mono CCDs is their high QE.  The fact they don't have Bayer filters allow them to adopt the LRGB color combination, in which they spend most of the time on L and only a little time on RGB. The L filter essentially uses the entire throughput range in the optical spectrum.  Coupled with the high QE of the sensors, this produces very high S/N and high resolution in a short amount of time.  This is proven to be an extremely efficient way of producing high quality color pictures, and DSLR just can't match this.  Even if DSLRs have similar QE as mono CCDs, it will still take a Bayer-style DSLR 2x (or even 3x) more exposure time to achieve the same quality. In my opinion, the biggest advantage of mono CCDs is their flexible filter usage, which allows for the very efficient LRGB and other possibilities.

Many people also think cooled CCDs are good because they are cooled and they have low noise.  Unfortunately, this is not correct.  First, recent DSLRs produced by Canon and Nikon all have LOWER noise comparing to CCDs from Kodak and Sony. Here I am talking about readout noise.  DSLRs' readout noise can be as low as 2-3 electrons rms per pixel (for example, 5D2 at ISO 1600 and 3200), but CCDs are still in the range of 7-10 (even > 10) electron per pixel. This is the same for dark current.  Recent Canon and Nikon CMOS chips have dark current that's MANY TIMES LOWER than that of Kodak/SONY CCD chips under the same temperature. The low temperature produced by the cooling system in those cooled CCDs help to reduce their dark current from being miserable to better than DSLRs, but not much better.  Plus, even when uncooled, recent DSLRs already have dark current that's comparable or even lower than sky photon rates in most astrophoto environments.  So dark current is no longer a limiting factor for the performance of DSLRs on astrophoto, as long as one subtract dark carefully, which is not difficult and doesn't take much time.

So, be happy with the Canon DSLRs you have.  They are great, maybe not up to the level of the best cooled CCDs, but not far behind too.

Wow.

That's a interesting post with some good points.  :)
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: outsider on April 05, 2012, 10:10:46 AM
It would have been nice if canon could have taken these same shots with a regular 60D to highlight the difference.

I wonder how much better the 60Da is over a stock 60D, or if this just marketing talk to market to the astronomer niche market?
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: epsiloneri on April 05, 2012, 10:14:26 AM
So dark current is no longer a limiting factor for the performance of DSLRs on astrophoto, as long as one subtract dark carefully, which is not difficult and doesn't take much time.
I'm very surprised to read this, but it sounds great! Do you have numbers for what the dark current actually is for modern DSLR sensors, e.g. in terms of electrons/hour?

Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: epsiloneri on April 05, 2012, 10:16:28 AM
It would have been nice if canon could have taken these same shots with a regular 60D to highlight the difference.
They did that for the Rosette nebula, in case you didn't see it. See OP.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: M.A.S. Productions on April 05, 2012, 10:51:48 AM
To me, the image from the 60D looks better. The image from the 60Da just looks more red.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: Heidrun on April 05, 2012, 10:54:37 AM
Hope that there wil come some pictures of the milky way with a wideangle lens and 60DA. Because if im gonna get this type of camera. I would 999 times out of 1000 use it to get pictures of the milky way or maybe Aurora Boralis
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: kdsand on April 05, 2012, 10:54:55 AM
 ;D

Just a thought ( ouch )

These pictures were actually taken with a Nikon........
 :o


No my bad its the other way around. :P
That is me being sarcastic
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: whwang on April 05, 2012, 11:07:34 AM
[I'm very surprised to read this, but it sounds great! Do you have numbers for what the dark current actually is for modern DSLR sensors, e.g. in terms of electrons/hour?


My own measurement on 5D2 is 0.86 electron per second at 20 deg C, and 0.051 electron per sec at 3 deg C. These are ambient temperature, not sensor temperature. The sensor must be much hotter after continuous operation of several 10s of minutes. The full report I wrote is here:
http://www3.asiaa.sinica.edu.tw/~whwang/misc/Canon5D2.pdf (http://www3.asiaa.sinica.edu.tw/~whwang/misc/Canon5D2.pdf)
It is oriented for astronomers.

In general, this page of Roger Clark's is an excellent source for sensor performance that amateur astronomers care:
http://www.clarkvision.com/articles/digital.sensor.performance.summary (http://www.clarkvision.com/articles/digital.sensor.performance.summary)
Unfortunately Roger's page does not contain much information on the dark rates.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: lol on April 05, 2012, 12:46:41 PM
I wonder how much better the 60Da is over a stock 60D, or if this just marketing talk to market to the astronomer niche market?
See following link for an indication of the possible difference, as they show the sensitivities of a 40D before and after modification. Note the increased red sensitivity, particularly around 6563 angstroms, which is where most of the "red glowy stuff" from nebulas sits. Assuming they haven't radically changed their colour filter since the 40D, then a similar gain is possible. Also note it doesn't significantly change the green or blue sensitivities.
http://www.astrosurf.com/buil/50d/test.htm (http://www.astrosurf.com/buil/50d/test.htm)


Hope that there wil come some pictures of the milky way with a wideangle lens and 60DA. Because if im gonna get this type of camera. I would 999 times out of 1000 use it to get pictures of the milky way or maybe Aurora Boralis
The IR filter modification only gets you a benefit in the deep reds. So for broader spectrum objects like galaxies (including the milky way) there isn't much benefit over a standard camera. I'm not familiar with the causes of the Aurora glow, so I'm not sure if the Da would or would not help there. If it did, it would only be from increased red sensitivity.

Note both the above assume Canon only changed the colour filter, and didn't make any other changes which may improve the image output.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: epsiloneri on April 06, 2012, 06:26:05 AM
My own measurement on 5D2 is 0.86 electron per second at 20 deg C, and 0.051 electron per sec at 3 deg C.
Thank you for doing this, very useful and interesting reading. Did you also characterise the variation of the flat field and the static dark current image? I.e., how much noise you would introduce by not correcting for flat field and dark. I've been impressed by how flat the dslr sensor appear compared to CCDs, so I've wondered if Canon actually has some first-order built-in flat fielder.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: whwang on April 06, 2012, 10:55:57 AM
Thank you for doing this, very useful and interesting reading. Did you also characterise the variation of the flat field and the static dark current image? I.e., how much noise you would introduce by not correcting for flat field and dark. I've been impressed by how flat the dslr sensor appear compared to CCDs, so I've wondered if Canon actually has some first-order built-in flat fielder.

For pixel response, modern sensors in the visible light are all very flat to begin with. This is true for both CCD and CMOS. I think, the most important flat field effect is introduced by the optics (vignetting) rather than by the sensors. Personally whenever I do astrophoto, I try to get a good flat field image to correct for the vignetting (and dust shadow).

For the dark part, as I mentioned in the PDF file, it is not possible (at least to my knowledge) to measure the real dark current in Canon CMOS. I can only measure the frame-to-frame variation of dark images, which is dark noise, and use that to infer what the dark current may be. The frame-to-frame variation is very small as long as temperature is stable. This means that a proper dark subtraction can remove thermal effect very cleanly and leaves very little trace of noise in a dark subtracted image.
Title: Re: First Canon EOS 60Da samples (Andromeda, Orion & Pleiades)!
Post by: epsiloneri on April 07, 2012, 05:51:45 PM
For the vignetting, I assume you would only have to take a "master flat" for the lens/camera combination once and for all, and then keep re-use it (much like is done in DPP and DxO). Dust may move around of course. I was more interested in the pixel-to-pixel variation of the flat field - how flat is very flat? If you haven't measured it - no problem I can do it myself when opportunity presents, I was just curious if you already had the data. Same thing for the dark current static structure - how much is the pixel-to-pixel variation? I understand it's a differential measurement, but one should anyway be able to measure this (otherwise one couldn't calibrate for it).

0.05 electrons/pix/sec is great performance, 1 electron/pix/sec not so much. The dark current seems to be (surprisingly) temperature sensitive in this regime. That means one needs to match the temperature of the sensor fairly accurately for the dark. Alternatively, optimise the dark subtraction by scaling it with the help of a bias frame.

The 5D2 sensor is also famous for some "band" structure in the dark that unfortunately is not stable in between exposures, and so very difficult to properly remove. Have you made any progress in this area? It will be interesting to see if the 60Da improves in this area.