51 replies to this topic

[mfarrell]

Hi all,

 

I received my ASI290MC directly from ZWO last Friday (after ordering it Tuesday night, a mere 66 hours before delivery...thanks Sam!).  After a few days of clouds and poor conditions, I had a chance to get first light this week.  I decided to do a little shootout with my current planetary imaging cam, the ASI178MM I've been using with RGB filters for the last 5 months or so.  Scope used was my CFF 160mm Apo Refractor and while the seeing was pretty good (~8/10 for this aperture) I'm not sure it would have supported the larger aperture of my C11 Edge.  In any case, the C11 wasn't cooled down and the refractor was ready to go.  'Nuff said.

 

OK, I know you guys and gals would probably rather see a comparison between 224MC and 290MC or between 178MM and 290MM, but I don't have those other cameras to compare to .  While my testing certainly wasn't controlled enough to be a rigorous comparison between a mono and color cam, the results are interesting nonetheless. 

 

Factors in favor of ASI178MM:

+ Color seems more pleasing at least after initial combination of RGB.  Color out of the color cam looks a little washed out in comparison and the saturation really needs to be cranked up to look similar, but it's still not identical possible due to the wider bandpasses in the color cam which gives less precise color reproduction?

+ Ability to get best focus for each color.  This can have benefits for refractors depending on which one we're talking about, but probably less so for SCT and pure reflectors shouldn't matter.  In my case with the CFF 160 I get best results by using the Baader T-size prism before the barlow lens & camera since it brings the main visual wavelengths to closer focus.

 

Factors in favor of ASI290MC:

+ This is not a scientific comparison, but the 290 seemed noticeably more sensitive than the 178.  We have larger pixels in the 290 and I used the same imaging train for both cameras, f/20, so the ASI178 is at a disadvantage in terms of light collected per pixel (tradeoff for smaller pixels and larger image scale).  I could have reduced the difference by matching image scale by using different barlows, but even then I think the 290 would appear more sensitive.  Another contributing factor for this could be that in the color cam, the green bandpass is wider than a green filter from an RGB setup.  In any case, I used exposure times of 4-8 ms for the 290MC while 8-15 ms is what I've typically been using for the 178MM.

+ Ability to capture time-specific events like moon/shadow transits, etc. without having to do photoshop work to match up the R/G/B from a mono cam.

+ Simplicity of operation and processing.  Compared to switching filters and refocusing (which admittedly could be automated) and then the additional processing workload, operating the color cam is practically point and shoot.  Stacking a single 60s sequence gives nice results, although of course taking multiple sequences and derotating them reduces noise and allows for more aggressive wavelets or stacking a smaller % of frames just as it does for a mono cam.

 

Note that I'm not viewing the pixel size as a positive or negative for either camera.  I can vary image scale by using different barlows, so I don't see the 2.4 um vs 2.9 um pixels as being a big differentiator.

 

Anyway, I'm pleased to see that ZWO seems to have another winner with the ASI290MC and I think it stands up very well to a recent mono cam, the ASI178MM.  It will be interesting to see future comparisons using other scopes and with the 290MM, which based on some early work from Darryl, appears to be a killer cam in the right hands !

 

I processed the two images below similarly but not identically.  Sharpening was probably a little more agressive on the 290MC from the looks of it, and I adjusted saturation and color balance to get a close match between the two.  The ASI178 image was reduced to 83% of original size to match the ASI290MC image scale.  Comments and observations welcome!

[easybob95]

Hello,

 

many thanks for this first feedback.

 

ASI290MC seems to be an intersting camera with great capabilities.

 

Alain

[AstroEthan]

Very nice comparison! ASI290MC looks much better to me.

 

I received my ASI290MC directly from ZWO last Friday (after ordering it Tuesday night, a mere 66 hours before delivery...thanks Sam!).

 

 

 

Lucky you! If I remember what my dad told me correctly, he pre-ordered our 290MM on the 8th of April. Hoping to get it soon, but it wouldn't matter much because the 10 days are filled with clouds and storms.

[Kokatha man]

A very good report, the first I've been privvy to!

I wish we could add some more sessions re the ASI290MM but we're sabotaged by clouds atm...

However, like your appraisal of the ASI290MC as a "winner" we're confident of a similar appraisal for the 290MM...we found that for the ASI224MC, & way back when the ASI120MC first came out that a boost in saturation & vibrancy always was required for comparable/satisfactory colour-renditions, particularly compared to the mono cameras...your comment about the Bayer matrix filters is relevant therein imo.

I'll be interested to hear how folks go who image Uranus & Neptune with the 290MC & iR filters - the 224MC gave us great outcomes last year which is why we hold high hopes for the 290MM...

Anyway, great report, especially for folks looking at a new colour camera - a "shoot-out" between the ASI290MC & the ASI224MC would be interesting even if I'm not sure how much difference could be ascertained!

[gfeulner]

Very nice comparison! ASI290MC looks much better to me.

I received my ASI290MC directly from ZWO last Friday (after ordering it Tuesday night, a mere 66 hours before delivery...thanks Sam!).

 
 
Lucky you! If I remember what my dad told me correctly, he pre-ordered our 290MM on the 8th of April. Hoping to get it soon, but it wouldn't matter much because the 10 days are filled with clouds and storms.

Now I don't feel so bad. Ordered mine two weeks ago and haven't heard anything.
Gerry

[TonyStar]

Thanks for the very informative report. I was curious if you had to pay import taxes on this purchase directly from China? 

[mfarrell]

Thanks for the very informative report. I was curious if you had to pay import taxes on this purchase directly from China? 

 

Nope, no import taxes/fees etc.  It came via UPS.

[erinviegas]

How good is this as an Autoguider? I need to use it for autoguiding (with an NEQ6 mount) as well as planetary imaging. Which one would you recommend 224MC or 290MC? I understand that the mono camera's are better for guiding, but would require additional RGB filters for planetary imaging and also this setup would cost a lot more. Hence I'm looking to go in for a color camera.

[mfarrell]

How good is this as an Autoguider? I need to use it for autoguiding (with an NEQ6 mount) as well as planetary imaging. Which one would you recommend 224MC or 290MC? I understand that the mono camera's are better for guiding, but would require additional RGB filters for planetary imaging and also this setup would cost a lot more. Hence I'm looking to go in for a color camera.

 

I haven't actually used the 290MC as an autoguider, but for fun, I checked to see what a 1 sec exposure would do at prime focus (f/10) in my 11" SCT.  I was able to see a mag 11 star at 0.5 sec and could reliably lock on at 1 sec.  Considering most guide scopes are faster than f/10, it would appear that the 290MC would work just fine as an autoguider.  That being said, the 224MC may be even better since it has larger pixels and will give a brighter image for the same exposure and gain.  For a short focal length guider like the popular 50mm guidescope, I might lean toward the 290MC since it has smaller pixels and you might get better guiding.  Since the guidescope has a fast f/ratio getting a guide star should be no problem.  For off axis guiding, i might prefer the 224MC since it has larger pixels and might be more sensitive.  But I would think that either would work fine, with the caveat that I haven't done any autoguiding with either camera yet (was still using the 120MM last time i did any autoguiding).

 

-Matthew

[mfarrell]

One note for folks interested in the 290MC vs 224MC...it appears that the 290MC has a built in IR block filter, so it doesn't seem suitable for using with an IR filter, unlike the 224MC as I understand it.  On Jupiter at f/10 with a 742nm IR filter, I had to go to 100ms exposure & 600 gain (max) just to even see Jupiter at all. 

 

A little disappointing, but Sam probably has a good reason for this...

 

-Matthew

[erinviegas]

 

How good is this as an Autoguider? I need to use it for autoguiding (with an NEQ6 mount) as well as planetary imaging. Which one would you recommend 224MC or 290MC? I understand that the mono camera's are better for guiding, but would require additional RGB filters for planetary imaging and also this setup would cost a lot more. Hence I'm looking to go in for a color camera.

 

I haven't actually used the 290MC as an autoguider, but for fun, I checked to see what a 1 sec exposure would do at prime focus (f/10) in my 11" SCT.  I was able to see a mag 11 star at 0.5 sec and could reliably lock on at 1 sec.  Considering most guide scopes are faster than f/10, it would appear that the 290MC would work just fine as an autoguider.  That being said, the 224MC may be even better since it has larger pixels and will give a brighter image for the same exposure and gain.  For a short focal length guider like the popular 50mm guidescope, I might lean toward the 290MC since it has smaller pixels and you might get better guiding.  Since the guidescope has a fast f/ratio getting a guide star should be no problem.  For off axis guiding, i might prefer the 224MC since it has larger pixels and might be more sensitive.  But I would think that either would work fine, with the caveat that I haven't done any autoguiding with either camera yet (was still using the 120MM last time i did any autoguiding).

 

-Matthew

 

 

 

One note for folks interested in the 290MC vs 224MC...it appears that the 290MC has a built in IR block filter, so it doesn't seem suitable for using with an IR filter, unlike the 224MC as I understand it.  On Jupiter at f/10 with a 742nm IR filter, I had to go to 100ms exposure & 600 gain (max) just to even see Jupiter at all. 

 

A little disappointing, but Sam probably has a good reason for this...

 

-Matthew

Thanks for your quick reply. From the specifications that i see on the ZWO website both have an AR coated window. Also were there any customs/import duty on the products ordered from the ZWO website? (As they ship from china)

[TonyStar]

A little disappointing, but Sam probably has a good reason for this...

 

This is extremely disappointing! Why limit the versatility of the camera when the sensitivity in the IR is as good as the 224MC?

It makes no sense to me. I'm wondering if this is an assembly line mistake. After all they are rushing to get these cameras out since supply isn't matching demand at this stage. I have asked Sam to clarify this filter issue...

 

Erinviegas, as Matthew said above, he didn't incur in any import taxes.

Edited by TonyStar, 17 May 2016 - 10:03 AM.

[cdavid]

Please pardon my lack of knowledge on this but ...I'm confused about the AR window and the need for IR cut filter.  So does the 290 color need the IR cut filter for planetary work?

 

Thanks

Carlos

[Nocturnal]

Yes, you should use an L filter for all color imaging work. I assume you know but the reason is different frequencies get diffracted differently and the IR would smudge your image and make it appear out of focus. When you get the camera try this for yourself. The difference in sharpness is quite amazing.

[TonyStar]

So does the 290 color need the IR cut filter for planetary work?

 

Thanks

Carlos

 

These cameras have a CMOS sensor with high sensitivity extending in the IR region (>800 nm) for low light applications. The sensitivity is the same for all RGB channels, so these cameras can be used effectively as mono IR cameras in conjunction with a IR pass filter. In this case the camera comes only with a protective AR window (which is transparent in the visible- near IR part of the spectrum). If used for color imaging you need to place an additional UV/IR cut filter in front of the camera otherwise your color balance will look way off (plus it's impossible to get a sharp focus with such extended spectral sensitivity). Matthew thinks his camera came with a IR cut filter instead of a AR window.

Edited by TonyStar, 17 May 2016 - 12:09 PM.

[Nocturnal]

If there is ever a doubt that your camera has an AR or IR filter, simply shine a TV remote on the sensor. No need for a scope or lens. Because even with an IR filter you will likely have a little 'bleed' you may want to use an extra L filter and compare with and without. If the sensor gets flooded with light without the L filter you have an AR window. If the brightness is comparable you have an IR filter. Or ask the manufacturer of course

[cdavid]

Yes, you should use an L filter for all color imaging work. I assume you know but the reason is different frequencies get diffracted differently and the IR would smudge your image and make it appear out of focus. When you get the camera try this for yourself. The difference in sharpness is quite amazing.

 

 

 

So does the 290 color need the IR cut filter for planetary work?

 

Thanks

Carlos

 

These cameras have a CMOS sensor with high sensitivity extending in the IR region (>800 nm) for low light applications. The sensitivity is the same for all RGB channels, so these cameras can be used effectively as mono IR cameras in conjunction with a IR pass filter. In this case the camera comes only with a protective AR window (which is transparent in the visible- near IR part of the spectrum). If used for color imaging you need to place an additional UV/IR cut filter in front of the camera otherwise your color balance will look way off (plus it's impossible to get a sharp focus with such extended spectral sensitivity). Matthew thinks his camera came with a IR cut filter instead of a AR window.

 

ok Thank you that makes more sense now.  I have been mainly a DSO imager using a full spectrum DSLR and similarly I need to use an IR blocking filter when imaging with a refractor or focus is not sharp.

 

... I guess I am unaware of imaging in which you want the IR band pass for planetary.  I have done some daylight IR imaging with my full spectrum camera....is there some analogous use in planetary ?

 

...one more question....it seems they are recommending the 290 mono for planetary but if you want a color cam they are still recommending the 224...is there a reason for this?

 

Thanks

Carlos

[Nocturnal]

Longer wavelengths are less affected by seeing. So bright objects (moon for example) can be imaged in IR and possibly result in sharper images. Using a red filter with a mono cam is a variation of this. Using a red filter with a color camera is pretty pointless so don't do that. With enough aperture you can image other targets (say Jupiter) in IR but "it depends" applies. It may be better to get all of RGB and shorten the exposure length and get more subs.

 

Whatever you do, don't be tempted to apply IR as an L channel to your RGB image. I know, this is what some (many) people do with HaRGB. Makes no sense at all. You would be dimming and brightening your colors based on how warm the same areas are. So if you have a cold area that is blue your low IR signal will knock that down and basically remove the blue from that area.

 

For lunar photography with an IR pass filter I recommend staying in mono. Keep in mind that your sensor will not be truly monochrome. My ASI224 still shows a bayer matrix in IR mode. If you are serious about IR photography a mono sensor is unsurpassed. Just to set your expectations :-)

 

As a side note my Astronomik IR Pass filter adds terrible reflections so I don't recommend it. If you are able to, borrow a filter from a friend before buying.

[TonyStar]

BTW Matthew, Sam said this camera should come with the AR window (not IR-block), as expected. 

The two filters have different coatings (the IR-block has a reddish glare compared to the AR window) so you can also tell visually

which one is installed on your camera... if your camera came with a IR-block window it must be an assembly error by ZWO.

[Gvs]

Just pulled the trigger on an ASI290MC.  Based on the sensor specs it can achieve 0.23 lux (the ASI224MC is 0.13 lux), though it has better contrast and resolution compared to the 224 sensor.  The 224 has been used for guiding without issues, so the 290 should not be too different.

 

The reason I have chosen this one as three fold.

1. Use it as and autoguider (do understand mono is better).
2. Use it as a planetary camera
3. Use it as show and tell for bright DSO objects (M27, M42, M57, M20, M31).

I'm a  newbie with CMOS or CCDs, as I only used unmodified DSLRs.  Some guidance and advice on filters and their impact would be appreciated.

[mfarrell]

BTW Matthew, Sam said this camera should come with the AR window (not IR-block), as expected. 

The two filters have different coatings (the IR-block has a reddish glare compared to the AR window) so you can also tell visually

which one is installed on your camera... if your camera came with a IR-block window it must be an assembly error by ZWO.

 

OK so I tried the TV remote trick on the 290MC and my 178MM, using a 742nm pass filter.

 

ASI178MM w/IR filter.  Gain = 0, exp = 100ms.  Entire image saturates when pressing the TV remote button.

ASI290MC w/IR filter.  Gain = 0, exp = 100ms.  Small white spot in the middle of the sensor when pressing the TV remote button.

 

Clearly the 290MC is picking up way less IR than the mono 178MM.

 

The picture below seals the deal:  the 290MC is on the left while the 178MM is on the right.  You can clearly see the difference in coating with the 290MC which I think confirms it has the IR block filter installed.

 

I'll be contacting Sam to see if he can send me an AR coated filter for the 290MC.

 

-Matthew

[TonyStar]

Yep, the difference is quite obvious...I'm wondering how easy it is to replace the window... you may void the warranty if you do it yourself. 

Sam may ask you to send it back....

[wenjha]

Hello guys

you are correct that we used the IR-CUT filter in the first batch of ASI290MC

it is our mistake, sorry

we will send the AR window to who need it, so you can exchange it yourself

[erinviegas]

Hello guys

you are correct that we used the IR-CUT filter in the first batch of ASI290MC

it is our mistake, sorry

we will send the AR window to who need it, so you can exchange it yourself

What about the one's that you will ship from now on? Are they also from the first batch? Also why is your official dealer not giving the introductory discount? http://www.highpoint...camera-asi290mc

[wenjha]

 

Hello guys

you are correct that we used the IR-CUT filter in the first batch of ASI290MC

it is our mistake, sorry

we will send the AR window to who need it, so you can exchange it yourself

What about the one's that you will ship from now on? Are they also from the first batch? Also why is your official dealer not giving the introductory discount? http://www.highpoint...camera-asi290mc

 

we corrected this issue once we found it

so new one will be AR window

we will ask HPS to adjust the price