ASI462 vs ASI224 (brief review, untracked planetary)

[sorrimen]

Hi all

Have had a couple sessions now with the asi462, with my untracked 8” dob 2x barlow and ADC. Prior to the asi462, I’ve been using the asi224 so I thought I’d write up a quick comparison. 

First things first, sampling. With the asi462 and my barlow + adc I’m pretty close to optimum, perhaps a bit over sampling based on UK seeing. With the asi224 I’m fairly undersampled. 

Onto specifics of the cameras. The larger sensor in the asi462 is incredibly useful for untracked AP. I don’t want to say it’s easy to locate the planets now, but having practiced with the asi224, often on a 800x600 ROI (too lazy to change back to max sometimes), it’s just so much more consistent. Point to the asi462.

Accurate colour in the asi462 is a challenge, or perhaps impossible without heading into Photoshop-type programs. This isn’t really an issue, as many of us are probably accustomed to the asi462 colour scheme from how many people use it. At first I was not a fan, but I very quickly grew to like it.

Asi462 offers slightly higher FPS. At 800x600 on my laptop, that’s 115 vs 103 for the asi224. Over 3 minutes that’s ~2000 frames which is definitely not insignificant. 

My impressions are that the asi462 is outperforming the asi224. This will largely be due to the proper sampling, though this is ultimately an imperfect comparison like almost every comparison will be by the nature of seeing variations etc. I’ve attached two images below, the first is my most detailed image from the asi224, the second my best attempt (out of 2 tries) with the asi462. 

Important to note that with the asi224 I’ve never been able to capture that much detail since. It was the 3rd session with any sort of planetary imaging, and looking back I must have just had absolutely incredible seeing relative to what I’ve had since. As a result, the detail is perhaps slightly greater, but the processing is harsher too so it’s not a fair comparison. The asi462 is still a winner given that I can achieve proper sampling much easier, and if I were to process it to the same degree it would likely be just as detailed. 

 

 

[Kon]

It's a nice little camera isn't it. I also use it with my manual 8" Dob. Invest on an IR pass filter since you can really use its sensitive on that wavelength.

5 hours ago, sorrimen said:

Asi462 offers slightly higher FPS. At 800x600 on my laptop, that’s 115 vs 103 for the asi224. Over 3 minutes that’s ~2000 frames which is definitely not insignificant. 

Seems to low; I regularly get max fps of 304 on a similar ROI (640*480) and at least 194 up to 1360*768. Do you use a USB3?

[Cosmic Geoff]

The ASI462 has a smaller pixel size, which gives a better match to a f10 SCT without using a Barlow lens (the best effective focal length depends on the camera pixel size).  I never had good results using a Barlow anyway.

A consequence of the smaller pixel size is that planets look bigger on the laptop screen.

With the same gain, the ASI462 offers shorter exposures - below 1ms on Mars and around 1ms on Jupiter.  

The maximum FPS is not greatly increased (USB3).

I used to process wholly with Registax, but with the ASI462 this gave rather bad results, and stacking with Autostakkert and final processing with Registax gives a much better result.  With the ASI462 it seems necessary to increase the colour saturation in Registax, otherwise the final images can look rather monochrome.

It is essential to use an IR-cut filter with the ASI462 to get a correct colour balance.  I recommend getting ZWO's IR-pass filter as well, so you can take infrared images.  With the ASI224MC, the infrared images were often sharper, but with the  ASI462MC I have not so far found that the IR images are any sharper than the OSC.

Overall I am satisfied with the ASI462MC and intend to use it for planetary imaging in preference to the ASI224MC.