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Help me choose my DSLR

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#1 DarkRise

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Posted 30 April 2016 - 08:01 AM

Hi there,

 

I just sold my canon 550d and I'm looking forward for a replacement. Here are the 3 camera I considering:

 

 

-Song A6300

-Samsung NX1(even if discontinued)

-Canon 7 Mk II

 

 

I would like to use the camera for both astro and land photo. I'm leaning toward the 7D Mk because of the following reason:

 

 

-Already have an canon IDAS clip LP filter

-Already have 2 canon lenses

-Easier to find somebody to mod it

-Astro Software support(already have APT and i love it)

 

My understanding is that both the NX1 and A6300 have better sensor and should perform better for astro work. I ,relatively , don't mind the 3 first considerations enumerated above, however it is unclear for me if both camera have USB to PC control capability and if there is any good software available for astro work(with bulb capability). 

 

 

 

Would it be safer to just go with the canon despite it might perform a little worst ?

 

Thanks


Edited by DarkRise, 30 April 2016 - 08:11 AM.


#2 entilza

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Posted 30 April 2016 - 08:44 AM

Based on what you said I would go with the Canon.



#3 bobzeq25

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Posted 30 April 2016 - 09:05 AM

The Canon is a decent, safe choice.  Not bad at all.  The biggest problem is the high read noise at low ISO, so you wind up using ISO 1600, with limited dynamic range.

 

If you're willing to give up the Canon lenses and filter, I recommend the $500 Nikon D5300, which is a bargain.  Better sensor, you can shoot at ISO200.  Low thermal noise, also.  Ha and (I believe) full spectrum mods available at LifePixel.  Good software compatibility, works with BackyardNikon, Sequence Generator Pro, no doubt others.

 

I have the very similar D5500, Ha modded by LifePixel.


Edited by bobzeq25, 30 April 2016 - 09:10 AM.


#4 jambi99

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Posted 30 April 2016 - 09:16 AM

The Canon is a decent, safe choice. Not bad at all. The biggest problem is the high read noise at low ISO, so you wind up using ISO 1600, with limited dynamic range.

If you're willing to give up the Canon lenses and filter, I recommend the $500 Nikon D5300, which is a bargain. Better sensor, you can shoot at ISO200. Low thermal noise, also. Ha and (I believe) full spectrum mods available at LifePixel. Good software compatibility, works with BackyardNikon, Sequence Generator Pro, no doubt others.

I have the very similar D5500, Ha modded by LifePixel.


Noted, what about the d7200 ?

#5 bobzeq25

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Posted 30 April 2016 - 09:37 AM

 

The Canon is a decent, safe choice. Not bad at all. The biggest problem is the high read noise at low ISO, so you wind up using ISO 1600, with limited dynamic range.

If you're willing to give up the Canon lenses and filter, I recommend the $500 Nikon D5300, which is a bargain. Better sensor, you can shoot at ISO200. Low thermal noise, also. Ha and (I believe) full spectrum mods available at LifePixel. Good software compatibility, works with BackyardNikon, Sequence Generator Pro, no doubt others.

I have the very similar D5500, Ha modded by LifePixel.


Noted, what about the d7200 ?

 

I don't have enough information to advise.  Here are some things I know the 5300 has, just don't know about the 7200.

 

Black point moved from 0 to 600.  Moire filter gone.  Both are useful.  Then there's the cost, if you're buying, instead of already have one. 

 

A personal thing is whether this is just an AP camera, or dual use.



#6 17.5Dob

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Posted 30 April 2016 - 02:12 PM

 

The Canon is a decent, safe choice. Not bad at all. The biggest problem is the high read noise at low ISO, so you wind up using ISO 1600, with limited dynamic range.

If you're willing to give up the Canon lenses and filter, I recommend the $500 Nikon D5300, which is a bargain. Better sensor, you can shoot at ISO200. Low thermal noise, also. Ha and (I believe) full spectrum mods available at LifePixel. Good software compatibility, works with BackyardNikon, Sequence Generator Pro, no doubt others.

I have the very similar D5500, Ha modded by LifePixel.


Noted, what about the d7200 ?

 

 

The D7200 uses a Toshiba sensor, supposedly the same one they used in the D7100, which I own, but with better autofocus and a bit less noise than the D7200. The D7200 is more like a D7100 v2.0. The D5300/5500 uses a Sony sensor and is quite a bit better than the Toshiba.

I use a full spectum modded D5300 for AP now instead of my D7100. There's no way I could ever get used to the handling of the D5300 for normal use. The D7100/7200 uses the same dual top wheel controls as their premium professional cameras. The D5300 is still partially BOC LCD menu driven. Thankfully, all I had to do was set it up once, and then let BYN handle it from there.

If this is going to be a dual use camera, than stay with the Canon.

 


Edited by 17.5Dob, 30 April 2016 - 02:17 PM.


#7 Jon Rista

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Posted 30 April 2016 - 11:08 PM

Are you willing to consider a mono CMOS camera? ZWO has just released their ASI1600 cooled mono CMOS cameras. They are cheaper than the 7D II at $1200, support regulated cooling to -40°C dT from ambient, support both LRGB and narrow band imaging, can be used with a wide variety of filter wheels, including motorized ones (Xagyl, $250; a set of basic Baader LRGB would probably get you up to a total cost in range with the 7D II). This camera is extremely low noise...3.5e- at low gain, down to 1.2e- at high gain. They are supported by APT. They wouldn't need to be modded (basically already is modded, no extra cost! ;P)

 

About the only thing it might not be compatible with (although I may have read about a clip-in EOS adapter for this, or that would work with it) is the IDAS filter. 

 

I just ordered one of these guys myself. Some of the initial test images from people in the BII forum with prelease/beta models are quite impressive. 

 

Anyway...DSLR isn't the only low cost option anymore. And not necessarily the best option. 

 

http://astronomy-ima...asi1600mm-cool/

 

EDIT: 

 

Sorry, just noticed that you wanted a camera for landscapes as well. Obviously this camera would not work for that...however, for astro, I do believe the ASI1600 is a better option than the DSLR/Mirrorless cameras listed. 


Edited by Jon Rista, 30 April 2016 - 11:25 PM.


#8 Jerry Lodriguss

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Posted 01 May 2016 - 06:18 PM

Are you willing to consider a mono CMOS camera? ZWO has just released their ASI1600 cooled mono CMOS cameras. They are cheaper than the 7D II at $1200, support regulated cooling to -40°C dT from ambient, support both LRGB and narrow band imaging, can be used with a wide variety of filter wheels, including motorized ones (Xagyl, $250; a set of basic Baader LRGB would probably get you up to a total cost in range with the 7D II). This camera is extremely low noise...3.5e- at low gain, down to 1.2e- at high gain. They are supported by APT. They wouldn't need to be modded (basically already is modded, no extra cost! ;P)

 

About the only thing it might not be compatible with (although I may have read about a clip-in EOS adapter for this, or that would work with it) is the IDAS filter. 

 

I just ordered one of these guys myself. Some of the initial test images from people in the BII forum with prelease/beta models are quite impressive. 

 

Anyway...DSLR isn't the only low cost option anymore. And not necessarily the best option. 

 

http://astronomy-ima...asi1600mm-cool/

 

EDIT: 

 

Sorry, just noticed that you wanted a camera for landscapes as well. Obviously this camera would not work for that...however, for astro, I do believe the ASI1600 is a better option than the DSLR/Mirrorless cameras listed. 

 

Hi Jon,

 

Although this discussion would seem more appropriate for the CCD, or Beginner's Forum, I have to ask about this ZWO ASI 1600 monochrome camera.

 

The specs on the ZWO page say it has 1.2 electrons of noise with a full well of 20,000 electrons, but only a 12-bit depth.

 

That doesn't make sense to me.

 

If you have a step size of 1.2 electrons, you would need 16,666 steps with a 20,000 electron well, but 12 bits only gives you 4,096 steps.

 

Ideally I think you would want to Nyquist sample the noise floor, so you would need 16 bits for 1.2 electrons of noise.

 

You could probably get away with 15 bits, but not 12.

 

So what are they doing here?

 

Jerry



#9 bobzeq25

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Posted 01 May 2016 - 10:32 PM

 

Are you willing to consider a mono CMOS camera? ZWO has just released their ASI1600 cooled mono CMOS cameras. They are cheaper than the 7D II at $1200, support regulated cooling to -40°C dT from ambient, support both LRGB and narrow band imaging, can be used with a wide variety of filter wheels, including motorized ones (Xagyl, $250; a set of basic Baader LRGB would probably get you up to a total cost in range with the 7D II). This camera is extremely low noise...3.5e- at low gain, down to 1.2e- at high gain. They are supported by APT. They wouldn't need to be modded (basically already is modded, no extra cost! ;P)

 

About the only thing it might not be compatible with (although I may have read about a clip-in EOS adapter for this, or that would work with it) is the IDAS filter. 

 

I just ordered one of these guys myself. Some of the initial test images from people in the BII forum with prelease/beta models are quite impressive. 

 

Anyway...DSLR isn't the only low cost option anymore. And not necessarily the best option. 

 

http://astronomy-ima...asi1600mm-cool/

 

EDIT: 

 

Sorry, just noticed that you wanted a camera for landscapes as well. Obviously this camera would not work for that...however, for astro, I do believe the ASI1600 is a better option than the DSLR/Mirrorless cameras listed. 

 

Hi Jon,

 

Although this discussion would seem more appropriate for the CCD, or Beginner's Forum, I have to ask about this ZWO ASI 1600 monochrome camera.

 

The specs on the ZWO page say it has 1.2 electrons of noise with a full well of 20,000 electrons, but only a 12-bit depth.

 

That doesn't make sense to me.

 

If you have a step size of 1.2 electrons, you would need 16,666 steps with a 20,000 electron well, but 12 bits only gives you 4,096 steps.

 

Ideally I think you would want to Nyquist sample the noise floor, so you would need 16 bits for 1.2 electrons of noise.

 

You could probably get away with 15 bits, but not 12.

 

So what are they doing here?

 

Jerry

 

I believe (not certain) that this is the answer.  Two parts.

 

I'm not understanding the focus on read noise.  There's no reason why the read noise needs to be one ADU.   It certainly isn't on my CCD.

 

I quite agree 12 bits is a drawback, that, with a 20,000 electron well depth, you're way undersampling the data.   Jon?


Edited by bobzeq25, 01 May 2016 - 10:39 PM.


#10 Jon Rista

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Posted 01 May 2016 - 11:17 PM

The ASI1600 has a 20ke- FWC wth 3.5e- RN at minimum gain. That is about 12.5 stops DR, or 12.5 bits of information (20,000/3.5). In contrast, a KAF-8300 has a 25.5ke- FWC with 8e- read noise, which gives it about 11.6 stops DR, or about 11.6 bits of information...so the ASI1600 has a lead here. Increasing bit depth doesn't really help you much, outside of possibly mitigating quantization noise. So I don't necessarily see 12 bits as a huge problem, although since it can resolve about 12.5 bits worth, I'd have preferred it to be 14-bit.

 

At unity gain, you obviously get 4096 discrete levels and therefor 12 stops DR/bits of information. You don't hit 1.2e- read noise until higher gain, where FWC is about 1000e-. At that point you have about 9.8 stops. 

 

So while you are throwing away half a bit at minimum gain, your not throwing away 4 bits worth of information. 



#11 Jerry Lodriguss

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Posted 02 May 2016 - 12:27 AM

The ASI1600 has a 20ke- FWC wth 3.5e- RN at minimum gain. That is about 12.5 stops DR, or 12.5 bits of information (20,000/3.5). In contrast, a KAF-8300 has a 25.5ke- FWC with 8e- read noise, which gives it about 11.6 stops DR, or about 11.6 bits of information...so the ASI1600 has a lead here. Increasing bit depth doesn't really help you much, outside of possibly mitigating quantization noise. So I don't necessarily see 12 bits as a huge problem, although since it can resolve about 12.5 bits worth, I'd have preferred it to be 14-bit.

 

At unity gain, you obviously get 4096 discrete levels and therefor 12 stops DR/bits of information. You don't hit 1.2e- read noise until higher gain, where FWC is about 1000e-. At that point you have about 9.8 stops. 

 

So while you are throwing away half a bit at minimum gain, your not throwing away 4 bits worth of information. 

 

So there are two gain settings?

 

And exactly what is the gain at the high setting, and what is the gain at the low setting?

 

Jerry



#12 Jon Rista

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Posted 02 May 2016 - 12:30 AM

It is variable gain, like most other planetary cameras. It ranges from 0 to 600. At 139 you reach unity. Read noise is 3.5 at 0, and drops to 1.2 as you approach 600 and bottoms out there. 



#13 Jerry Lodriguss

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Posted 02 May 2016 - 01:49 AM

It is variable gain, like most other planetary cameras. It ranges from 0 to 600. At 139 you reach unity. Read noise is 3.5 at 0, and drops to 1.2 as you approach 600 and bottoms out there. 

 

Hi Jon,

 

I don't understand what 0 gain means.

 

Gain defines how many electrons are represented by each Analog to Digital Unit.

 

How can you have zero electrons assigned to an ADU?

 

Jerry



#14 Jon Rista

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Posted 02 May 2016 - 02:17 AM

It is just a setting value, not the actual voltage gain or e-/ADU ratio (they don't list that detail). At setting 0, you are at minimum gain. At setting 600, you are at maximum gain. According to ZWO's information, a setting of 139 is unity gain, so 4096e- == 4096 ADU. You can choose any gain setting value from 0 through 600, so you have very fine control. The driver also has three canned settings, low gain, high gain, and unity gain. From what I can tell from ZWO's site, you have ~1.75e- RN at unity gain, for DR of ~67.4dB or 11.23 stops. 

 

To put that in DSLR terms. My 5D III has 4070e- saturation at ISO 1600, with read noise of 3.8e-. That gives me 60.5dB or 10 stops DR. The 6D has 5127e- FWC and 3.1e- read noise for 64.4dB or 10.7 stops DR. So the ASI at unity gain has about a 1 1/4 stop edge on my 5D III when it comes to dynamic range...not counting the other benefits of a mono sensor like a full 100% pixel fill factor, or the higher Q.E. (sounds like it will be around 60%), the ability to do narrow band imaging, the ability to do high speed or lucky imaging with ROI, etc.


Edited by Jon Rista, 02 May 2016 - 02:45 AM.


#15 Jerry Lodriguss

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Posted 02 May 2016 - 02:36 AM

It is just a setting value, not the actual voltage gain or e-/ADU ratio (they don't list that detail). At setting 0, you are at minimum gain. At setting 600, you are at maximum gain. According to ZWO's information, a setting of 139 is unity gain, so 4096e- == 4096 ADU. 

 

I'm just trying to figure out the specs on this camera, I'm interested in it.

 

So at a "setting" of zero, we are at minimum gain, but we don't know what it is?

 

Is ZWO specifically saying that the gain at the zero setting is 3.5e-, the same as the read noise?  Or are you just assuming that? Or has someone actually measured it?

 

Just because the read noise is 3.5e-, doesn't necessarily mean that is what the gain is.

 

What is the read noise at unity gain?

 

And at a "setting" of  600, we are at maximum gain, but again we don't know what it is?

 

It seems like these specs should be listed for a camera intended for astronomical use.

 

I looked at the ZWO web page for the camera, and  here are some other questions I had:

 

1. What is the thermal signal?

2. Is the chamber sealed? 

3. Is the chamber filled with an inert gas?

4. What is the mating thread?

5. Is it USB2 or USB3?

6. Does it have Win 10 drivers?

 

Thanks,

 

Jerry


Edited by Jerry Lodriguss, 02 May 2016 - 02:41 AM.


#16 Jon Rista

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Posted 02 May 2016 - 02:59 AM

I updated my previous answer with some more info.

 

I have not seen what the actual gain setting in e-/ADU is. ZWO has not reported it. However, it is easy enough to derive, assuming all the other info is correct. The camera uses a 12-bit ADC. It has 3.5e- read noise at minimum gain, with the FWC of 20ke-. That gives us 20000e-/4096ADU conversion rate, or ~4.9e-/ADU at minimum gain (gain setting 0). At gain setting 139 the gain is 1e-/ADU. At a gain setting of ~260 you hit minimum read noise of ~1.2e-, with an FWC of 1000, for a gain of ~0.24e-/ADU. 

 

The camera uses regulated cooling, down to -40 to -45 C dT below ambient. The ZWO rep posted a dark current chart in one of the threads in BII...I'll see if I can dig it up. From what I remember, at -10C and colder, dark current was very low. There is some low-level amp glow, however in example narrow band images, it has calibrated out very well. In only one image did I see anything that looked like a glow remnant...however the owner of the image said it might have been a reflection or gradient from the moon as well. Overall, the dark current seems to be well managed, and when cooled, it is quite low. Competitively low at the very least, if not better than the KAF-8300.

 

The camera is USB3. It is the same 4/3 format as the KAF-8300. I am not sure if the chamber is sealed, I do not believe it is filled with inert gas, though. It uses a female M42 thread by default with a backfocus requirement of 17.5mm, however the female T-thread adapter can be removed to expose a male M42 thread, which if used with Precise Parts custom adapters, would give you a mere 6.5mm backfocus (I am actually going to be doing this myself to adapt it to the Atik EFW2 FW and give myself enough backfocus to use a thin 10mm Telescop Service EF mount adapter to adapt the camera and FW to my 600mm Canon lens.) 

 

I am not sure if it has Windows 10 drivers. I am still using Windows 8 on my main computer, where I'll be doing most imaging, so I did not check on that. The details should be on ZWO's site, though:

 

https://astronomy-im...asi1600mm-cool/

 

Oh, and FWIW, the camera is releasing this month. It's brand new. I'm kind of taking the plunge in preordering, so I don't yet have first hand experience with it, nor have I had the opportunity to actually do any measurements. There are a couple of individuals who have beta cameras who have shared some data in the BII forum in one of a few threads about the camera. You can look there for more info. I'm impressed with everything except the amp glow so far, however I am not terribly concerned about the amp glow. I've been dealing with that for years with my 5D III, and it should be far easier to deal with when operating at a regulated temperature.

 

In terms of overall build quality...it is not going to be as high end nor as refined as a KAF CCD camera from SBIG, QSI, FLI, etc. If you want that grade of quality, then you are probably better off still going with a CCD for now. The KAF-8300 cameras are basically direct competitors. That said...you will spend 3-4x as much at the very least on a CCD...as the ASI1600 is currently under $1200. 


Edited by Jon Rista, 02 May 2016 - 03:08 AM.


#17 Jerry Lodriguss

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Posted 02 May 2016 - 03:19 AM

I updated my previous answer with some more info.

 

I have not seen what the actual gain setting in e-/ADU is. ZWO has not reported it. However, it is easy enough to derive, assuming all the other info is correct. The camera uses a 12-bit ADC. It has 3.5e- read noise at minimum gain, with the FWC of 20ke-. That gives us 20000e-/4096ADU conversion rate, or ~4.9e-/ADU at minimum gain (gain setting 0). At gain setting 139 the gain is 1e-/ADU. At a gain setting of ~260 you hit minimum read noise of ~1.2e-, with an FWC of 1000, for a gain of ~0.24e-/ADU. 

 

The camera uses regulated cooling, down to -40 to -45 C dT below ambient. The ZWO rep posted a dark current chart in one of the threads in BII...I'll see if I can dig it up. From what I remember, at -10C and colder, dark current was very low. There is some low-level amp glow, however in example narrow band images, it has calibrated out very well. In only one image did I see anything that looked like a glow remnant...however the owner of the image said it might have been a reflection or gradient from the moon as well. Overall, the dark current seems to be well managed, and when cooled, it is quite low. Competitively low at the very least, if not better than the KAF-8300.

 

The camera is USB3. It is the same 4/3 format as the KAF-8300. I am not sure if the chamber is sealed, I do not believe it is filled with inert gas, though. It uses a female M42 thread by default with a backfocus requirement of 17.5mm, however the female T-thread adapter can be removed to expose a male M42 thread, which if used with Precise Parts custom adapters, would give you a mere 6.5mm backfocus (I am actually going to be doing this myself to adapt it to the Atik EFW2 FW and give myself enough backfocus to use a thin 10mm Telescop Service EF mount adapter to adapt the camera and FW to my 600mm Canon lens.) 

 

I am not sure if it has Windows 10 drivers. I am still using Windows 8 on my main computer, where I'll be doing most imaging, so I did not check on that. The details should be on ZWO's site, though:

 

https://astronomy-im...asi1600mm-cool/

 

Oh, and FWIW, the camera is releasing this month. It's brand new. I'm kind of taking the plunge in preordering, so I don't yet have first hand experience with it, nor have I had the opportunity to actually do any measurements. There are a couple of individuals who have beta cameras who have shared some data in the BII forum in one of a few threads about the camera. You can look there for more info. I'm impressed with everything except the amp glow so far, however I am not terribly concerned about the amp glow. I've been dealing with that for years with my 5D III, and it should be far easier to deal with when operating at a regulated temperature.

 

In terms of overall build quality...it is not going to be as high end nor as refined as a KAF CCD camera from SBIG, QSI, FLI, etc. If you want that grade of quality, then you are probably better off still going with a CCD for now. The KAF-8300 cameras are basically direct competitors. That said...you will spend 3-4x as much at the very least on a CCD...as the ASI1600 is currently under $1200. 

 

Hi Jon,

 

Thanks for the info, it seems some specs are in graphs here:

 

https://www.astronom...-FW-vs-gain.jpg

 

Jerry



#18 bobzeq25

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Posted 02 May 2016 - 10:45 AM

 

I updated my previous answer with some more info.

 

I have not seen what the actual gain setting in e-/ADU is. ZWO has not reported it. However, it is easy enough to derive, assuming all the other info is correct. The camera uses a 12-bit ADC. It has 3.5e- read noise at minimum gain, with the FWC of 20ke-. That gives us 20000e-/4096ADU conversion rate, or ~4.9e-/ADU at minimum gain (gain setting 0). At gain setting 139 the gain is 1e-/ADU. At a gain setting of ~260 you hit minimum read noise of ~1.2e-, with an FWC of 1000, for a gain of ~0.24e-/ADU. 

 

The camera uses regulated cooling, down to -40 to -45 C dT below ambient. The ZWO rep posted a dark current chart in one of the threads in BII...I'll see if I can dig it up. From what I remember, at -10C and colder, dark current was very low. There is some low-level amp glow, however in example narrow band images, it has calibrated out very well. In only one image did I see anything that looked like a glow remnant...however the owner of the image said it might have been a reflection or gradient from the moon as well. Overall, the dark current seems to be well managed, and when cooled, it is quite low. Competitively low at the very least, if not better than the KAF-8300.

 

The camera is USB3. It is the same 4/3 format as the KAF-8300. I am not sure if the chamber is sealed, I do not believe it is filled with inert gas, though. It uses a female M42 thread by default with a backfocus requirement of 17.5mm, however the female T-thread adapter can be removed to expose a male M42 thread, which if used with Precise Parts custom adapters, would give you a mere 6.5mm backfocus (I am actually going to be doing this myself to adapt it to the Atik EFW2 FW and give myself enough backfocus to use a thin 10mm Telescop Service EF mount adapter to adapt the camera and FW to my 600mm Canon lens.) 

 

I am not sure if it has Windows 10 drivers. I am still using Windows 8 on my main computer, where I'll be doing most imaging, so I did not check on that. The details should be on ZWO's site, though:

 

https://astronomy-im...asi1600mm-cool/

 

Oh, and FWIW, the camera is releasing this month. It's brand new. I'm kind of taking the plunge in preordering, so I don't yet have first hand experience with it, nor have I had the opportunity to actually do any measurements. There are a couple of individuals who have beta cameras who have shared some data in the BII forum in one of a few threads about the camera. You can look there for more info. I'm impressed with everything except the amp glow so far, however I am not terribly concerned about the amp glow. I've been dealing with that for years with my 5D III, and it should be far easier to deal with when operating at a regulated temperature.

 

In terms of overall build quality...it is not going to be as high end nor as refined as a KAF CCD camera from SBIG, QSI, FLI, etc. If you want that grade of quality, then you are probably better off still going with a CCD for now. The KAF-8300 cameras are basically direct competitors. That said...you will spend 3-4x as much at the very least on a CCD...as the ASI1600 is currently under $1200. 

 

Hi Jon,

 

Thanks for the info, it seems some specs are in graphs here:

 

https://www.astronom...-FW-vs-gain.jpg

 

Jerry

 

Please forgive ignorant questions, and educate me.

 

So, looking at this, it appears as though, to get the benefits of low read noise, you don't want to operate the 1600 much (if at all) below unity gain?  And, at unity gain, the DR is a bit over 11 stops, so 12 bit processing is fine?

 

Kind of like how you don't want to use an older Canon much below ISO800, because the read noise is skyrocketing?

 

Am I getting this?  Does calibrating with a suitable number of bias frames change anything at all?

 

And how does my $2500 Atik 460EXM compare?  20,000 full well, 4 read noise.  No doubt similar cooling and quantum efficiency.   Setting aside the larger chip, is the 1600 just as good, or better?  The 16 bit processing on the 460 just a useless frill?  If "quality" on the 460 is better, how so?

 

I really don't mind if my vaunted camera has been made obsolete.  I just would like to know.


Edited by bobzeq25, 02 May 2016 - 10:55 AM.


#19 Jon Rista

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Posted 02 May 2016 - 11:02 AM

At 20ke-/4e- RN, you are doing quite well on the dynamic range front. You have ~12.3 stops. So while 16-bit isn't exactly necessary, 14-bit would allow you to make full use of the DR the camera can offer. Still, losing a third of a bit isn't a particularly huge deal. The stars that are going to clip with 12 bits are going to clip with 14 or 16 bits. 

 

Calibrating the ASI1600 cleans up it's glows quite well. After that, it's like any other signal, just with lower read noise than most (even at minimum gain). Personally, I'll operate the ASI1600 at minimum gain if I need the DR, however for the most part, I think I'll be using it at unity. It is much like using a DSLR at the ISO closest to unity, however the difference with the ASI is you don't end up with 30e- read noise if you decide to use minimum gain. You have, tops, 3.5e- read noise, which is about what most DSLRs get at high ISO. 

 

Since you already have the Atik 460 Bob, I don't think there are many compelling reasons for you to move to the ASI1600. You wouldn't see much change is my guess, however I don't believe the Atik 460 has any glow issues...so you actually ahead of the curve a bit there. If you already have a CCD camera, there still isn't a whole lot of reasons to upgrade. The ASI does support high speed imaging with video, starting at 23fps at full res, and increasing to 200fps with smaller ROI. That could be a benefit...it makes the camera viable for planetary, lunar, solar...lucky imaging, etc. 



#20 t_image

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Posted 02 May 2016 - 11:13 AM

DarkRise,

 

back to the cameras.

I imagine you have researched the details and specs, but just so no one gets blinded by tunnel vision:

 

Both the NX1 and the a6300 can film 4K video. I know everyone just cares about photos, but 4K video can make lunar, solar, planetary fun sometimes.

Since you will be doing terrestrial day work as well, I'm sure there will be moments you want to future-proof your videos with great resolution.

 

I enjoy the Sony e mount.

#1 there is no difference between my full frame a7s and my a5000 as far as lens that will work.

#2 I use manual focus/aperture so have no problem with a simple mechanical adapter to use my nice Canon and Nikon lenses (I don't have a Sony lens except the kit zoom).

#3 mirrorless cameras are built for constant live-view. Having an EVF is so fun.

#4 the a6300 not only shoots 4K video, it can shoot 1080HD video at 120fps. 120fps is a lot of frames, but is really helpful for slow mo and planetary.

 

 

you don't have BYEOS and that is a deal breaker for some. All depends on what you want to do.

I have no problem with my workflow using an intervalvometer and an external display.

The wifi phone/tablet app can also do lots for you.

 

 

 

 



#21 HaleBopper

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Posted 02 May 2016 - 04:09 PM

DarkRise, I have been thinking about the 7D Mk II myself. For pretty much have the same reasons as you. Anyway,here is a link you might want to have a look at:

 

http://www.clarkvisi...ion-canon-7dii/

 

Hope it helps you decide.



#22 DarkRise

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Posted 02 May 2016 - 09:38 PM

Thanks for help guys. What do you think of the nikon d600? Better than the 7d2 or the d5500?

#23 bobzeq25

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Posted 03 May 2016 - 12:15 AM

Thanks for help guys. What do you think of the nikon d600? Better than the 7d2 or the d5500?

Different animal, a full frame.  Are your optics suitable to cover it?  Many aren't, can vignette excessively.

 

The issue about black point I noted in #5 applies.

 

I have a D5500, and like it, but it's hard to justify the $200 price increase over the D5300, unless the touch screen is important to you.

 

I only use it for astro, where it shines.  Check out terrestrial reviews, see if others have 17.5Dobs issues about the controls.



#24 Herra Kuulapaa

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Posted 03 May 2016 - 02:02 AM

Thanks for help guys. What do you think of the nikon d600? Better than the 7d2 or the d5500?

 

You will get bigger pixels (~6um) with full frame D600, lower noise and larger full well capacity. At unity gain (ISO500) the well capacity is ~17ke-. I have found my D600 more capable when lifting shadows than D5100, which is not very surprising considering it’s full frame and the other one is a crop (D600 has 55% larger pixel surface area).

 

The question is in the end about your scope. You need a bigger and better (more expensive) telescope to cover the full frame sensor like previously mentioned. With smaller pixel size you get more “reach” and smaller scopes are suitable as well. This is the reason why I like to image sun with D5100am instead of D600am.

 

I personally would love to jump into ASI1600 world, but I find the sensor size a bit limited and also the pixel size for narrow band imaging.
Let’s make a brief comparison with pixel sizes of 3.8um, 4.78um and 5.95um: With D600 I get 1.5x the pixel surface of the D5100, and 2.5x the ASI1600. Also both DSLRs beat the ASI1600 with well capacity when imaging at unity gain. But don’t get me wrong, ASI1600 is a step into right direction, I just wish to have a bit more..


Edited by Herra Kuulapaa, 03 May 2016 - 02:29 AM.


#25 bobzeq25

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Posted 03 May 2016 - 09:17 AM

 

I personally would love to jump into ASI1600 world, but I find the sensor size a bit limited and also the pixel size for narrow band imaging.
Let’s make a brief comparison with pixel sizes of 3.8um, 4.78um and 5.95um: With D600 I get 1.5x the pixel surface of the D5100, and 2.5x the ASI1600. Also both DSLRs beat the ASI1600 with well capacity when imaging at unity gain. But don’t get me wrong, ASI1600 is a step into right direction, I just wish to have a bit more..

 

You like a DSLR for narrowband?  You're basically using only 25% of the pixels with each filter.  The mono 1600 (or other mono camera) has to be better, pixel size must be less important than that.  You could bin the mono camera 2X2, and come out way ahead.




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