| Upgrading from a Zenithstar 61 with a Canon DSLR, which option would be best? | |
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| ASI533MC-Pro Dedicated Camera | |
| FRA400 OTA | |
| Other (please comment) | |
| Login to vote and view results. |
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Mark Germani: I've been taking a look at some of your images and I at least agree that white and bluish stars are showing a bit too much of a blue halo. However, this can be for several reasons which includes post-processing. On some of the images, I've the impression that your white balance is shifted towards blue and hence it can give a false impression. How do you color-calibrate your images? The FLAT61A isn't just a flattener but also a reducer and those combos are more sensitive to backfocus errors. I recommend to invest some time into making sure that it the correct distance. In my experience, the scale on the WO flattener/reducers are fairly accurate and should bring you quite close to the correct value. If there is indeed tilt, only a tilt adapter will fix it. As I said and have to admit: I never use sensors larger than APS-C (at the moment I'm just using 16mm diagonals) and one reason among several others is: it gives you less headache on backfocus and tilt. The draw back is the smaller FOV and so I do what photographers do: I'm changing lenses, i.e., scopes (RedCat51 @ 250mm, ZS81@ 450mm and an EdgeHD @ 2000mm). CS, Björn |
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Björn: Hi Björn! I think I might be a bit heavy-handed with the SCNR at times, maybe that's a factor? I use SPCC for colour calibration, but only since January of this year when I moved to PixInsight, so if you're looking at anything older than that, it may or may not be colour calibrated. I used to use Siril for calibration, but it didn't always work well with my data so only used it some of the time. Björn: The FLAT61A is a 1:1 flattener, but there is a FLAT61R which is a flattener-reducer combo (0.8x), unless I am mistaken. I have had to play around with the backspacing to minimize the tilt - I move it until the coma in one corner is no more pronounced than the astigmatism in the opposite corner, which I assumed would mean that the backspacing would be correct for the middle of the frame. the Neumann CTU is rather expensive and it's not the camera sensor that is tilted - I have confirmed this by changing the rotation of my camera and observing the tilt changing locations - so I'm not sure it would solve my issue, unless it can be mounted between the OTA and the flattener (unless my flattener is creating the tilt - what a headache!) You may be right about the backspacing leading to CA, but there's not much I can do until the tilt issue is sorted, otherwise I'll have very bad coma in one corner...  I appreciate all the input - thanks so much and CS! |
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Just ordered the ASI533MC-Pro. You guys are amazing - thanks for all the advice! I've distilled the advice on this thread to: - Consider alternatives to the FRA400 with longer FL - Maybe have another go at sorting the tilt on the ZS61 - Maybe go mono for the next camera? Clear skies to you all! |
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=16pxThanks Jay! That clinches it. There's a review of the ASI533MC-Pro by Damian Peach=16px and he says it's not much better than a modded DSLR, but I have a hard time taking that at face value, as I think the improvement will be noticeable, though I've never used a dedicated camera so it's hard to know for sure. I really appreciate all the first-hand experience you and others have brought to this thread. Astrobin is a super resource! *what planet is that reviewer on? 533 is a large sensor? Heavy? Not much better than a DSLR? Utter nonsense |
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=16pxThanks Jay! That clinches it. There's a review of the ASI533MC-Pro by Damian Peach=16px and he says it's not much better than a modded DSLR, but I have a hard time taking that at face value, as I think the improvement will be noticeable, though I've never used a dedicated camera so it's hard to know for sure. I really appreciate all the first-hand experience you and others have brought to this thread. Astrobin is a super resource! Wow that review is terrible. “A separate power supply is only needed if you wish to run the camera cooling system (only really need for very long exposure work)” ……… no wonder he’s getting the same results as a DSLR 😂 |
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=16pxThanks Jay! That clinches it. There's a review of the ASI533MC-Pro by Damian Peach=16px and he says it's not much better than a modded DSLR, but I have a hard time taking that at face value, as I think the improvement will be noticeable, though I've never used a dedicated camera so it's hard to know for sure. I really appreciate all the first-hand experience you and others have brought to this thread. Astrobin is a super resource! * I think he is reviewing it from a planetary imaging perspective. That's the only way the review makes any sense. The 533 is a great DSO imaging camera, low noise, 14 bit, decent full well depth, great for the price, forgiving of tilt, off axis abberation etc being square |
