Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

ZWO 290mm Mini Guidecam - Beta Test Thread

  • Please log in to reply
130 replies to this topic

#76 rockstarbill

rockstarbill

    Fly Me to the Moon

  • *****
  • Posts: 6,598
  • Joined: 16 Jul 2013
  • Loc: Snohomish, WA

Posted 05 October 2017 - 07:03 PM

The 174 is wonderful. Plenty of good stars to choose from due to the large sensor. 


  • mikefulb likes this

#77 Robert York

Robert York

    Messenger

  • -----
  • Posts: 462
  • Joined: 05 May 2013
  • Loc: Near Dallas, TX

Posted 06 October 2017 - 12:44 AM

How do either of these compare to the SBIG ST-i? I have one from years ago, and I'm wondering how things have progressed, since.



#78 gotak

gotak

    Vanguard

  • *****
  • Posts: 2,100
  • Joined: 18 Sep 2016
  • Loc: Toronto, CA

Posted 06 October 2017 - 01:37 PM

Ordered the 174 mini from ZWO yesterday. But order still being prepared today. How long's shipping typically?



#79 ChrisWhite

ChrisWhite

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 5,027
  • Joined: 28 Feb 2015
  • Loc: Colchester, VT

Posted 06 October 2017 - 06:02 PM

Bill, glad to hear that 174 is working out well for you! Something I noticed with the 290 and the tiny pixels, is that if I binned I actually got slightly better performance.  The real benefit of binning for me though was that with my ugly OAG stars PHD would choose better qualified guidestars when autoselecting. 

 

I've been using the standard 290mm for guiding for quite a while now on one setup, and now using the 290 mini on another.  I'm not surprised by how many good guidestars I have to choose from, but I am extremely pleased with it! 


  • rockstarbill and bsavoie like this

#80 Andy Grant

Andy Grant

    Sputnik

  • -----
  • Posts: 49
  • Joined: 16 Sep 2017
  • Loc: Cary, NC, USA

Posted 06 October 2017 - 11:32 PM

For Andy the passage through the prism is optically shorter than in air by about 4mm or so. As a result the distance from the middle of the long side of the prism to the imaging sensor should be about 4mm less than from that point on the prism to the guide sensor.

If you can measure things you may be able to tell if a camera will work or not.

A helical focuser is nice and good focus of the oag guidestar is important. But I find that if the guide camera can operate at high frame rate like video then it is easy to focus accurately just with the draw tube and thumb screws.

Often the helical focuser takes up too much backfocus but you may be able to slide the camera into it and use it.

Frank

So I think in my case I might 'need' a 1.25" barrel camera (or a different OAG).  The OAG I have seems to really be for eyepieces (which is not surprising as it was made before digital cameras were common).  I took a friend's ASI120, slid it into my OAG using it's 1.25" nosepiece, took a rough estimate, and came up with 2.5-3" between the OAG's mirror and the 120's sensor.  That doesn't seem ideal.  I'm still coming up to speed on all this, but at a minimum I think that would mean vignetting, wasting the larger sensor on these cameras.

 

I guess I either need to go with a 1.25" barrel guiding cam, or look into a different OAG assembly.  What are the current recommended OAG assemblies for 8" SCTs?

 

Assuming I go with the 1.25" barrel ASI290, how much would I be giving up when using it for planetary imaging (since it only has USB 2.0)?



#81 rockstarbill

rockstarbill

    Fly Me to the Moon

  • *****
  • Posts: 6,598
  • Joined: 16 Jul 2013
  • Loc: Snohomish, WA

Posted 07 October 2017 - 12:12 AM

Bill, glad to hear that 174 is working out well for you! Something I noticed with the 290 and the tiny pixels, is that if I binned I actually got slightly better performance.  The real benefit of binning for me though was that with my ugly OAG stars PHD would choose better qualified guidestars when autoselecting. 

 

I've been using the standard 290mm for guiding for quite a while now on one setup, and now using the 290 mini on another.  I'm not surprised by how many good guidestars I have to choose from, but I am extremely pleased with it! 

I will try binning for the heck of it to see what the experience is like with the 174. Cant hurt to try. waytogo.gif



#82 Stargazer3236

Stargazer3236

    Soyuz

  • ****-
  • Posts: 3,827
  • Joined: 07 Aug 2010
  • Loc: Waltham, MA

Posted 07 October 2017 - 12:51 AM

I guess I was shot down when I asked previously if the 290 mini cam could be used for DSO imaging. However, many folks bought the Rising Tech 290's and they were only USB 2.0. Does it really matter about frames per second when imaging DSO's?

 

It has the same chip and the same non-cooling feature that it's big sister has, so why not make a good DSO imaging cam?

 

Also, it has the USB-C type connector, wouldn't USB 3.0 work with it, or is that in the hardware of the cam?


  • ChrisWhite likes this

#83 iuseglasses

iuseglasses

    Mariner 2

  • *****
  • Posts: 272
  • Joined: 19 May 2013
  • Loc: Central Texas

Posted 07 October 2017 - 01:02 AM

I guess I was shot down when I asked previously if the 290 mini cam could be used for DSO imaging. However, many folks bought the Rising Tech 290's and they were only USB 2.0. Does it really matter about frames per second when imaging DSO's?

It has the same chip and the same non-cooling feature that it's big sister has, so why not make a good DSO imaging cam?

Also, it has the USB-C type connector, wouldn't USB 3.0 work with it, or is that in the hardware of the cam?


USB-C is a connector standard. It doesn’t necessarily imply what it’s capable of. Thunderbolt 3 uses the USB-C connector and it does way more than just USB. It can definitely be confusing.


Sent from my iPhone using Tapatalk

#84 ChrisWhite

ChrisWhite

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 5,027
  • Joined: 28 Feb 2015
  • Loc: Colchester, VT

Posted 07 October 2017 - 07:02 AM

I guess I was shot down when I asked previously if the 290 mini cam could be used for DSO imaging. However, many folks bought the Rising Tech 290's and they were only USB 2.0. Does it really matter about frames per second when imaging DSO's?

 

It has the same chip and the same non-cooling feature that it's big sister has, so why not make a good DSO imaging cam?

 

Also, it has the USB-C type connector, wouldn't USB 3.0 work with it, or is that in the hardware of the cam?

 

David,

 

You could use the mini for DSO, however in my opinion neither this nor the USB 3 version would be ideal for DSO.  Setpoint cooling in my opinion is a critical feature of any mono imaging camera.  I know this jacks the price quite a bit, but the ability to cool the sensor and be able to easily match calibration frames to this temp cannot be understated. 

 

There appears to be some differences with some of the ZWO cameras when it comes to AMP Glow and some noise with respect to how quickly you download the files from the camera, so there may be some additional real world benefits to USB 3 for DSO.  Naturally if you are doing planetary or lunar USB 3 will be a big benefit for being able to shoot video or high FPS.

 

Another thing to consider is the chip size.  The 290 has a pretty small chip, so you would have a very limited Field of View for DSO.  A larger chip such as the 174, 178 or 1600 would likely be a better match, depending on your scope of course. 

 

Hope this helps. 


  • bsavoie likes this

#85 Robert York

Robert York

    Messenger

  • -----
  • Posts: 462
  • Joined: 05 May 2013
  • Loc: Near Dallas, TX

Posted 07 October 2017 - 09:36 AM

My question seems to have gotten quietly overlooked.. so I'll give a little more details. It's a 4.8x3.6 mono CCD, 7.4um pixels (640x480). http://diffractionli...m/product/st-i/ Seems a bit archaic by todays standards. How do you think one of these two new cams would compare?



#86 mikefulb

mikefulb

    Surveyor 1

  • *****
  • Posts: 1,739
  • Joined: 17 Apr 2006

Posted 07 October 2017 - 10:43 AM

My question seems to have gotten quietly overlooked.. so I'll give a little more details. It's a 4.8x3.6 mono CCD, 7.4um pixels (640x480). http://diffractionli...m/product/st-i/ Seems a bit archaic by todays standards. How do you think one of these two new cams would compare?

I don't think it is even in the same league - it is a relic from the past.  It has higher read noise, has an actual mechanical shutter (failure mode waiting to happen) and would be pretty useless for planetary/lunar/solar imaging if you ever wanted to use it that way.

 

I think even the cheap Rising Tech imx224 cameras you can get for < $200 would be a better choice.



#87 Robert York

Robert York

    Messenger

  • -----
  • Posts: 462
  • Joined: 05 May 2013
  • Loc: Near Dallas, TX

Posted 07 October 2017 - 10:52 AM

Well, seems i might have a month to wait for my mono cam setup. Was pondering getting a new guide cam but using it as a cheap DSO cam for the interim. Only, having OSC would be kinda nice, at least for an interim cam. I could do old-school mono imaging. I have an IR/UV cut and Ha filter.

 

If that were the option, which of these would be the more flexible option? Seems like the 290 is the more accurate guide camera. I plan on using a guide scope most of the time. I have an OAG, but in general, guide scope works great for my focal lengths (1000mm or less). Or maybe spend a little more on an ASI178?



#88 Stelios

Stelios

    Cosmos

  • *****
  • Moderators
  • Posts: 8,204
  • Joined: 04 Oct 2003
  • Loc: West Hills, CA

Posted 07 October 2017 - 11:12 AM

Well, seems i might have a month to wait for my mono cam setup. Was pondering getting a new guide cam but using it as a cheap DSO cam for the interim. Only, having OSC would be kinda nice, at least for an interim cam. I could do old-school mono imaging. I have an IR/UV cut and Ha filter.

 

If that were the option, which of these would be the more flexible option? Seems like the 290 is the more accurate guide camera. I plan on using a guide scope most of the time. I have an OAG, but in general, guide scope works great for my focal lengths (1000mm or less). Or maybe spend a little more on an ASI178?

Buy for the long term and not for the interim. The 290 is a great guide camera. The ASI178 has the pancake form, so in that format the ASI290 costs the same. If you don't buy cooled, you'll have little benefit, so make do with a DSLR in the interim (I assume you have one).



#89 alphatripleplus

alphatripleplus

    World Controller

  • *****
  • Moderators
  • Posts: 103,863
  • Joined: 09 Mar 2012
  • Loc: Georgia

Posted 10 October 2017 - 03:32 PM

 


 

 

You could use the mini for DSO, however in my opinion neither this nor the USB 3 version would be ideal for DSO.  Setpoint cooling in my opinion is a critical feature of any mono imaging camera.  I know this jacks the price quite a bit, but the ability to cool the sensor and be able to easily match calibration frames to this temp cannot be understated. 

 

There appears to be some differences with some of the ZWO cameras when it comes to AMP Glow and some noise with respect to how quickly you download the files from the camera, so there may be some additional real world benefits to USB 3 for DSO.  Naturally if you are doing planetary or lunar USB 3 will be a big benefit for being able to shoot video or high FPS.

 

Another thing to consider is the chip size.  The 290 has a pretty small chip, so you would have a very limited Field of View for DSO.  A larger chip such as the 174, 178 or 1600 would likely be a better match, depending on your scope of course. 

 

Hope this helps. 

 

Chris,

 

I understand that your comments primarily address the use of the 290 mini as a guide camera, and you've also indicated its shortcomings with respect to use as an AP imaging camera in terms of a small chip and lack of cooling.

 

However, I think several of us, perhaps including David, are interested in its potential use  as an EAA camera for DSOs, with live stacking of  subs typically ranging  from 5s -15s and the camera used at high gain, say 350. There are already quite a few EAA users of the uncooled USB3 ASI290MM using those sorts of settings, and I suspect there will be a lot of interest in the 290 mini from the EAA crowd. It doesn't look like any of us has one yet, so I would ask if in your test usage you see any evidence of more noise associated with the USB2 290 mini compared with the regular USB3 290, as you indicated this could be a possibility with slower download speeds. We will probably open a separate thread on EAA usage of the camera in the EAA forum once people have them, but if you have any comments on whether there is additional noise associated with the USB2 version it might be helpful. Thanks.

 

Errol


  • bsavoie and mAnKiNd like this

#90 ChrisWhite

ChrisWhite

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 5,027
  • Joined: 28 Feb 2015
  • Loc: Colchester, VT

Posted 10 October 2017 - 07:54 PM

Errol,

 

I am unable to comment on the use of this camera for EAA. 

 

It's possible the image quality aspect of the mini would be identical to the usb 3.0 version, and download speed might have nothing to do with it.  I know USB limit speeds have a meaningful impact on image quality with the 1600, but keep in mind that this chip is much smaller and the files are also much smaller, so this may not even be a consideration. 

 

I have only used my 290mm and 290mini for guiding so I don't have much of a data point for you.  I think this would be a great question for Sam at ZWO. 

 

I could run some dark frame tests if you like so you could compare, although I'm not sure this would satisfy your curiosity Sorry I cannot be more helpful. 


  • alphatripleplus likes this

#91 iuseglasses

iuseglasses

    Mariner 2

  • *****
  • Posts: 272
  • Joined: 19 May 2013
  • Loc: Central Texas

Posted 10 October 2017 - 11:01 PM

I’ve been using the 290mini a few nights now. Happy to say it’s worked flawlessly with an Orion ST80. I live in a white zone and it finds more stars at 1 sec exposure than I could ever use


Sent from my iPhone using Tapatalk

#92 alphatripleplus

alphatripleplus

    World Controller

  • *****
  • Moderators
  • Posts: 103,863
  • Joined: 09 Mar 2012
  • Loc: Georgia

Posted 10 October 2017 - 11:37 PM

Thanks, Chris - I will follow your advice and ask Sam the question.



#93 premk19

premk19

    Viking 1

  • *****
  • Posts: 698
  • Joined: 19 Apr 2015

Posted 16 October 2017 - 02:29 PM

Guiding with a 290mini on a 80mm f/6 refractor and OAG. I consistently get guide stars with SNR 300+, sometimes even 400+ with occasional saturation. This is at the 'lowest read noise' gain setting. I have used a QHY5III 174 before, the 290 is a lot cleaner. I don't find dark calibration necessary. It does however have a significantly smaller field of view compared to the 174, but in most cases the OAG prism will be the limiting factor rather than the guide chip size.

 

wCzVO3h.png


  • bsavoie likes this

#94 ChrisWhite

ChrisWhite

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 5,027
  • Joined: 28 Feb 2015
  • Loc: Colchester, VT

Posted 16 October 2017 - 05:12 PM

Guiding with a 290mini on a 80mm f/6 refractor and OAG. I consistently get guide stars with SNR 300+, sometimes even 400+ with occasional saturation. This is at the 'lowest read noise' gain setting. I have used a QHY5III 174 before, the 290 is a lot cleaner. I don't find dark calibration necessary. It does however have a significantly smaller field of view compared to the 174, but in most cases the OAG prism will be the limiting factor rather than the guide chip size.

I have not tried at such a high gain yet.  I set it at Gain 80 and left it.  I had tons of stars in the 60 to 120 SNR range.  

 

From what I understand you don't want to clip stars too much as it does not allow PHD to calculate an accurate centroid.  I can't argue with your RMS error though.  Looks like your guiding is good. 

 

In general, is there benefit to getting stars with such high SNR, or is there a magic point?  I believe that where you set a target SNR in PHD you max out at 100.



#95 Robert York

Robert York

    Messenger

  • -----
  • Posts: 462
  • Joined: 05 May 2013
  • Loc: Near Dallas, TX

Posted 16 October 2017 - 05:35 PM

I still can't decide between a 290mini or the 178mm. I've decided it's for guiding only. I'll get a separate camera for OSC if I want to fiddle with that.

 

Any suggestions?



#96 ChrisWhite

ChrisWhite

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 5,027
  • Joined: 28 Feb 2015
  • Loc: Colchester, VT

Posted 16 October 2017 - 05:44 PM

I still can't decide between a 290mini or the 178mm. I've decided it's for guiding only. I'll get a separate camera for OSC if I want to fiddle with that.

 

Any suggestions?

 

For guiding only?  The 290mini.  It's cheaper, sensitive and with the 1.25" body format gives you more freedom for orientation and it's easy to fine-tune focus by sliding it in and out of the holder. 


Edited by ChrisWhite, 16 October 2017 - 05:44 PM.

  • bsavoie likes this

#97 premk19

premk19

    Viking 1

  • *****
  • Posts: 698
  • Joined: 19 Apr 2015

Posted 17 October 2017 - 01:51 PM

 

Guiding with a 290mini on a 80mm f/6 refractor and OAG. I consistently get guide stars with SNR 300+, sometimes even 400+ with occasional saturation. This is at the 'lowest read noise' gain setting. I have used a QHY5III 174 before, the 290 is a lot cleaner. I don't find dark calibration necessary. It does however have a significantly smaller field of view compared to the 174, but in most cases the OAG prism will be the limiting factor rather than the guide chip size.

I have not tried at such a high gain yet.  I set it at Gain 80 and left it.  I had tons of stars in the 60 to 120 SNR range.  

 

From what I understand you don't want to clip stars too much as it does not allow PHD to calculate an accurate centroid.  I can't argue with your RMS error though.  Looks like your guiding is good. 

 

In general, is there benefit to getting stars with such high SNR, or is there a magic point?  I believe that where you set a target SNR in PHD you max out at 100.

 

Higher the SNR, the better. Until the star is saturated, of course. Since we use short exposures with guiding, it's good to have read noise as low as possible, so I always choose the lowest read noise preset in the ASCOM driver. Many stars do get clipped, but PHD always auto selects a non-clipped star. That night I was guiding on that star for 4+ hours with SNR in the 300s, but the star was never saturated. It also helps to de-focus the guide star a bit, as it's easier of PHD to calculate centroid.


  • bsavoie and ChrisWhite like this

#98 ChrisWhite

ChrisWhite

    Fly Me to the Moon

  • *****
  • topic starter
  • Posts: 5,027
  • Joined: 28 Feb 2015
  • Loc: Colchester, VT

Posted 17 October 2017 - 08:06 PM

 

 

Guiding with a 290mini on a 80mm f/6 refractor and OAG. I consistently get guide stars with SNR 300+, sometimes even 400+ with occasional saturation. This is at the 'lowest read noise' gain setting. I have used a QHY5III 174 before, the 290 is a lot cleaner. I don't find dark calibration necessary. It does however have a significantly smaller field of view compared to the 174, but in most cases the OAG prism will be the limiting factor rather than the guide chip size.

I have not tried at such a high gain yet.  I set it at Gain 80 and left it.  I had tons of stars in the 60 to 120 SNR range.  

 

From what I understand you don't want to clip stars too much as it does not allow PHD to calculate an accurate centroid.  I can't argue with your RMS error though.  Looks like your guiding is good. 

 

In general, is there benefit to getting stars with such high SNR, or is there a magic point?  I believe that where you set a target SNR in PHD you max out at 100.

 

Higher the SNR, the better. Until the star is saturated, of course. Since we use short exposures with guiding, it's good to have read noise as low as possible, so I always choose the lowest read noise preset in the ASCOM driver. Many stars do get clipped, but PHD always auto selects a non-clipped star. That night I was guiding on that star for 4+ hours with SNR in the 300s, but the star was never saturated. It also helps to de-focus the guide star a bit, as it's easier of PHD to calculate centroid.

 

I'll give it a try.

 

Do you set a target SNR in PHD or just let it do it;s thing?



#99 premk19

premk19

    Viking 1

  • *****
  • Posts: 698
  • Joined: 19 Apr 2015

Posted 17 October 2017 - 11:36 PM

 

 

 

Guiding with a 290mini on a 80mm f/6 refractor and OAG. I consistently get guide stars with SNR 300+, sometimes even 400+ with occasional saturation. This is at the 'lowest read noise' gain setting. I have used a QHY5III 174 before, the 290 is a lot cleaner. I don't find dark calibration necessary. It does however have a significantly smaller field of view compared to the 174, but in most cases the OAG prism will be the limiting factor rather than the guide chip size.

I have not tried at such a high gain yet.  I set it at Gain 80 and left it.  I had tons of stars in the 60 to 120 SNR range.  

 

From what I understand you don't want to clip stars too much as it does not allow PHD to calculate an accurate centroid.  I can't argue with your RMS error though.  Looks like your guiding is good. 

 

In general, is there benefit to getting stars with such high SNR, or is there a magic point?  I believe that where you set a target SNR in PHD you max out at 100.

 

Higher the SNR, the better. Until the star is saturated, of course. Since we use short exposures with guiding, it's good to have read noise as low as possible, so I always choose the lowest read noise preset in the ASCOM driver. Many stars do get clipped, but PHD always auto selects a non-clipped star. That night I was guiding on that star for 4+ hours with SNR in the 300s, but the star was never saturated. It also helps to de-focus the guide star a bit, as it's easier of PHD to calculate centroid.

 

I'll give it a try.

 

Do you set a target SNR in PHD or just let it do it;s thing?

 

I just let PHD atuo select a star. It always seems to pick a star with highest snr and without saturation.



#100 Robert York

Robert York

    Messenger

  • -----
  • Posts: 462
  • Joined: 05 May 2013
  • Loc: Near Dallas, TX

Posted 18 October 2017 - 12:15 AM

Got my ASI290 mini ordered. Should have it this weekend, hopefully.




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics