Difference between cameras with the same sensor

[andrew s]

Unfortunately,  we don't have an astronomy press that quantitatively compares equipment. While with optics this is difficult with CCD or CMOS cameras the basics can be easily  measured. In fact anyone set up to do astro photography can do it.

It is also a fact of life few if any SGLers will have access to multiple equipment with, in this case, the same camera chips. That's why we have not been able to help.

I did point out the only comparison I new about which showed camera can differ but it was not the chip you were interested in.

Regards Andrew 

Edited November 11, 2020 by andrew s

[FLO]

7 hours ago, Andy274 said:

That's my experience im afraid Steve

Sorry to hear you feel that way. I can assure you that was not his intention. Ian is not a fob-you-off kinda guy 🙂 

HTH

Steve 

[johninderby]

6 minutes ago, FLO said:

 

Ian is not a fob-you-off kinda guy 🙂 

 

Have had the pleasure of dealing with Ian a few times and he must the most helpful person out there. 👍🏻👍🏻👍🏻

[gilesco]

45 minutes ago, andrew s said:

Unfortunately,  we don't have an astronomy press that quantitatively compares equipment. While with optics this is difficult with CCD or CMOS cameras the basics can be easily  measured. In fact anyone set up to do astro photography can do it.

It is also a fact of life few if any SGLers will have access to multiple equipment with, in this case, the same camera chips. That's why we have not been able to help.

I did point out the only comparison I new about which showed camera can differ but it was not the chip you were interested in.

A good way to ascertain the quality of a particular piece of equipment in a "by and large" and "in general way" it just to peruse the various galleries of images that get posted on various websites (e.g. astrobin).

These images are generally posted with metadata which informs you all about the equipment and software that was used to obtain and produce them, and often a little about the methodology involved.

This is what drove me to buy my ZWO cameras, which at the time I thought very competitively priced. I think I would continue to buy ZWO in the future, not exclusively, but no reason not to. The only time I had to contact support online via their forums was with a broken ASIStudio on Linux, they responded pretty quickly. 

I'm failing to tie up some of the comments in this thread with my own experiences...

[MartinB]

51 minutes ago, Andy274 said:

That's my experience im afraid Steve, I did feel thoroughly fobbed off by Ian - asked 1 or 2 questions which I answered then bounced me to ZWO support. I understand that I may be an outlier with that experience.

The end of my post stated that I'll buy what's right for me & not because its any particular brand but because its what I believe will work. 

The whole point of this post was to ask for details in the difference between the 3 brands of camera so I could make an informed choice & so far nobody had been able to give me one.

Instead my post had been filled with partisan affiliation which frankly isn't helpful. 

Not the intention to rubbish any brand, but quite within my rights to share my experience on here - whether people agree or not. 

Cheers

Andy

Andy, you have asked about a camera which, as far as I am aware, is only available "pre order".   Any response is bound to be speculative and likely to include reference to what members have experience of.  It is also no surprise to find "partisan affiliation" from satisfied customers.  You have now managed to critisise the members who have taken the time to respond, FLO and a hugely respected member of the astro retail community.  Also you have implied in this thread the notion that members will be leaving in droves to another forum.  You have asked a perfectly sensible question so it would be a shame if the thread descended into rancour.  I am very interested to hear about this camera!

[andrew s]

54 minutes ago, gilesco said:

A good way to ascertain the quality of a particular piece of equipment in a "by and large" and "in general way" it just to peruse the various galleries of images that get posted on various websites (e.g. astrobin).

These images are generally posted with metadata which informs you all about the equipment and software that was used to obtain and produce them, and often a little about the methodology involved.

This is what drove me to buy my ZWO cameras, which at the time I thought very competitively priced. I think I would continue to buy ZWO in the future, not exclusively, but no reason not to. The only time I had to contact support online via their forums was with a broken ASIStudio on Linux, they responded pretty quickly. 

I'm failing to tie up some of the comments in this thread with my own experiences...

Certainly you can do that. You can also very easily check your camera to see if it meets specification.  Gain, dark current, linearity, well depth, cooling capacity.

When comparing images there are many factors in play. Not least of which are optics, sky conditions and processing skills. Personally given what can now be done in software post processing it's not clear to me how you would isolate the camera from all else that is in play.

However, I realise I am in a minority on this issue in astronomy but not it seems with general photography where they seem to value measurement as well as subjective comparisons. 

Regards Andrew 

[Andy274]

57 minutes ago, MartinB said:

Andy, you have asked about a camera which, as far as I am aware, is only available "pre order".   Any response is bound to be speculative and likely to include reference to what members have experience of.  It is also no surprise to find "partisan affiliation" from satisfied customers.  You have now managed to critisise the members who have taken the time to respond, FLO and a hugely respected member of the astro retail community.  Also you have implied in this thread the notion that members will be leaving in droves to another forum.  You have asked a perfectly sensible question so it would be a shame if the thread descended into rancour.  I am very interested to hear about this camera!

In what way have I criticised SGL members that have responded Martin? 

By partisan affiliation with regard to any astronomical brand, I liken it to supporting a football team - some people will only buy a particular brand etc, not in any way can that be construed as criticising anyone. 

No offence was meant to Steve, FLO or Ian, but I think I'm safe enough to describe my experience - im not in China or North Korea. 

I really don't want to get into the politics of brand bashing, not my thing, the post was started by asking an open & honest question - which still stands. 

The proof of the pudding will be in the images I guess, now all we really need to work on is a de-cloud machine. 

If we can all work on that we'd be onto a winner!

Cheers

Andy

[tomato]

If you want a summary of the differences between the ZWO and QHY offerings, take a look at the end of this review:

https://www.amateurastrophotography.com/qhy268c-test-report

[vlaiv]

I don't believe there will be much difference in images produced with same sensor regardless of the camera vendor (if other variables are kept reasonably the same - scope, mount, sky quality, etc ...).

I think it is more about things like - how good camera casing is, what is the weight, are there any reflections from camera sensor cover window, what about power consumption. Is USB connection stable? How good are the drivers.

User experience in general. Sensor will be the same after all so data produced will be very similar.

[Adam J]

1 hour ago, vlaiv said:

I don't believe there will be much difference in images produced with same sensor regardless of the camera vendor (if other variables are kept reasonably the same - scope, mount, sky quality, etc ...).

I think it is more about things like - how good camera casing is, what is the weight, are there any reflections from camera sensor cover window, what about power consumption. Is USB connection stable? How good are the drivers.

User experience in general. Sensor will be the same after all so data produced will be very similar.

Yes I agree, if its working as intended then its unlikely that you would see much difference, but build quality, support, drivers and other factors need to be considered.

Personally on those grounds I would not look to skimp on a couple of hundred pounds and would just get the thing from a Make / vendor with a good reputation.

This is a good look at the ASI1600mm pro vs the ATIK Horizon for example. 

http://www.astrosurf.com/buil/atik_vs_zwo/

Adam

Edited November 11, 2020 by Adam J

[gilesco]

The imaging sensor is a single component, it needs to be mounted onto a PCB, and attached to whole set of other components, probably including:

• Some sort of Microcontroller
• Some sort of Memory and memory buffer
• Some clock mechansim
• Cooling Mechanism
• USB Controllers
• etc...

All the above cost additional to the sensor, it is likely that the £500 you are looking to save is being saved in the above components, because everyone is buying the imaging sensor for the same price, and only the bigger customers will be able to get a small edge on the sensor alone.

I used to work for a manufacturer of IT components, and one of the products was a SoundBlaster 16 compatible sound card. I was providing the UK support for the imported products. Then one day someone phoned up with a strange issue, he had recorded something via his soundcard and sent it to a friend to playback. The friend reported that it sounded like the guy had been breathing Helium. So he played it back on his computer and it sounded normal.

What had happened? Well I asked him to return the sound card and examined it. It turns out on the new batch of imported cards the PCB assembler had decided to wire an existing 25Mhz clock to the chipset where it actually required a 33Mhz clock (or was it vice versa). Thus not having to put both clocks on the PCB and saving themselves about 25p per card. So when a user recorded a sound at a sampling rate of say 44kHz, they actually recorded at a different kHz value. It would play back fine on a similarly defunct card, but on cards that had the correct clock wiring the sampling would be wrong.

And, anyway, the Altair might become a game changes, it might cause other manufacturers to lower prices, or it might have stretched the limits of cost savings to affect operability and performance.

As far as we know, given the lack of response so far to your questions, very few are out there in use, and as you say, not much chance of the clouds breaking either (here in the UK). We're happy that you or someone will take the jump and report back though.

 

[vlaiv]

5 minutes ago, gilesco said:

All the above cost additional to the sensor, it is likely that the £500 you are looking to save is being saved in the above components, because everyone is buying the imaging sensor for the same price, and only the bigger customers will be able to get a small edge on the sensor alone.

I highly doubt that astronomy camera manufacturers actually have their own R&D teams that put together all that.

I believe they just take the reference implementation and pack it into suitable housing. I bet that if one took two different cameras apart, one would find same electronics next to sensor.

[gilesco]

5 minutes ago, vlaiv said:

I highly doubt that astronomy camera manufacturers actually have their own R&D teams that put together all that.

I believe they just take the reference implementation and pack it into suitable housing. I bet that if one took two different cameras apart, one would find same electronics next to sensor.

Yes, the sensor will come with a spec sheet that will detail how it needs to be connected, but I'm certain that ZWO assemble the components and solder them onto the PCB, hence the ASI120S Rev1.6 marking on this board, if it wasn't ZWO, they wouldn't call it ASI

[andrew s]

7 minutes ago, vlaiv said:

I highly doubt that astronomy camera manufacturers actually have their own R&D teams that put together all that.

I believe they just take the reference implementation and pack it into suitable housing. I bet that if one took two different cameras apart, one would find same electronics next to sensor.

Interestingly Starlight Xpress did experiment with the clocking on their CSX 304 CMOS camera to reduce amp glow. Regards Andrew 

[Adam J]

5 minutes ago, gilesco said:

Yes, the sensor will come with a spec sheet that will detail how it needs to be connected, but I'm certain that ZWO assemble the components and solder them onto the PCB, hence the ASI120S Rev1.6 marking on this board, if it wasn't ZWO, they wouldn't call it ASI

What Vlaiv means is that they are likely working with the same chip set as specfied by sony along with the interface diagram etc etc. I am sure they do assemble their own boards etc as you say.

[Adam J]

6 minutes ago, andrew s said:

Interestingly Starlight Xpress did experiment with the clocking on their CSX 304 CMOS camera to reduce amp glow. Regards Andrew 

Yes I remamber having a chat with them about that at the 2019 parctical astronomy show and it sounded promissing but I have still not seen an image from that camera anywhere on the internet.

Its a complete unknown, you would think someone must own one by now though.

Adam

[vlaiv]

1 minute ago, Adam J said:

What Vlaiv means is that they are likely working with the same chip set as specfied by sony along with the interface diagram etc etc. I am sure they do assemble their own boards etc as you say.

Exactly, it's not overly complicated to turn reference design into PCB layout - there is software to do that easily and board printing companies expect that you send them layout in particular format.

[Andy274]

This is exactly the type of debate I was hoping to generate guys. I agree with Vlaiv, I don't think there will be much difference - hence the whole reason for the post. 

When my camera arrives & if we ever get a clear night I'll be out there & we'll see what's what

[johninderby]

I think a lot has to do with personal experience with different brands. Had problems with an Altair camera so sent it back but zero problems with a couple of ZWO cameras so now I would buy ZWO over Altair. 🙂

Find ZWO has better support than Altair  in terms of drivers.

Edited November 11, 2020 by johninderby

[vlaiv]

In that tone, here is my direct comparison between QHY and ASI. I used to have QHY5IILc and I now exclusively have ASI cameras.

This is of course limited "sample size" to be able to draw any serious conclusions, but at the time I had QHY camera - it was very much lacking in drivers department / software support. I did not have such issues with ASI range. On the other hand, I had some issues with ASI range - that turned out not to be issues with cameras themselves but rather USB system. Once I added powered USB hub and changed USB cables - everything works without any issues.

Fact that I now have 3 ASI cameras says something about their quality I suppose.

[gilesco]

29 minutes ago, vlaiv said:

Exactly, it's not overly complicated to turn reference design into PCB layout - there is software to do that easily and board printing companies expect that you send them layout in particular format.

The picture also shows that there have been multiple revisions since original production (assuming v1.0 was the initial production version). These revisions come about for various reasons:

• A supplier of a particular component no longer becomes available, or a cheaper but equivalent component becomes available.
• Minor changes, e.g. They discover that while the reference specification may ask to use resistors with a 5% error tolerance, that they can get away with cheaper resistors with a 10% error tolerance, without any hit on their Q&A (although over time this may affect operational life of the device).
• More major changes - for example, introducing programmable firmware, where the firmware was not programmable in a prior release.

I've worked for manufacturers producing PCBs, you would be amazed at the levels of cost cutting and production optimisations that are considered during a single product's life. Some affect the overall life of a product, but that is less of a concern towards the end of a products support cycle.

In any case, I don't think cameras that use the same sensor are always effectively the same, every manufacturer has to go through a process of optimisation for cost, and there are lots of options from the reference specification to implement differing performing cameras where the only thing they might share is the imaging sensor.

[Adam J]

17 hours ago, vlaiv said:

In that tone, here is my direct comparison between QHY and ASI. I used to have QHY5IILc and I now exclusively have ASI cameras.

The QHY5IILc was notorious.

[smr]

It might well be that the Altair offering is a good performer, perhaps basically identical in terms of optical performance and stability and therefore a superb buy in that you're saving £300 over the ZWO and QHY Cameras, but it could take a while before it's established as to whether or not that it so, with the QHY and ZWO Cameras they've been out for a fair while now and I've not heard of any criticisms with either of them. 

 

[Planitair]

On 11/11/2020 at 12:49, Andy274 said:

That's my experience im afraid Steve, I did feel thoroughly fobbed off by Ian - asked 1 or 2 questions which I answered then bounced me to ZWO support. I understand that I may be an outlier with that experience.

The end of my post stated that I'll buy what's right for me & not because its any particular brand but because its what I believe will work. 

The whole point of this post was to ask for details in the difference between the 3 brands of camera so I could make an informed choice & so far nobody had been able to give me one.

Instead my post had been filled with partisan affiliation which frankly isn't helpful. 

Not the intention to rubbish any brand, but quite within my rights to share my experience on here - whether people agree or not. 

Cheers

Andy

Andy, As I have previously mentioned, the choice of Kit especially Camera for Astro is very, very Subjective, you choose what is right for you, and of course it is worth reading up on differing brands & assosciated cameras to assist you in decision making, however, at the end of the day its your choice and no one else.

Eric

[pete_l]

There are two things I am sure of WRT this discussion.

First is that nobody could inspect three images each of the same subject, taken under identical conditions and accurately say which image was from which camera.

Second, I am even more sure that nobody would ever run such a test ;(

Yer pays yer money and makes yer choice! Everyone will give reasons why their purchasing decision was better than others who chose differently. It would take an individual of exceptional character to admit that they spent several £ thousand on a camera and that it is unsatisfactory. Not faulty, simply inferior. Although I am (thirdly! ) sure that happens very often. Just look at what gets put up for sale s/h.

Edited November 15, 2020 by pete_l