Worthy upgrade for 1600MM-PRO (Poll)

Topic starter

Apr 16, 2022

Which will be a worthy upgrade?

I already have 1600 MM PRO used for more than 2 years.

Deciding to switch to OSC to 2600MC

Do give your poll about it considering following reasons.

533MM (same size filters can be used)
294MM (larger pixels + same size filters can be used)
533MC (for Higher QE)
294MC (for Larger Pixels)
2600MC (for 16 Bit)

kuechlew

Apr 16, 2022

Just copying my questions from this post: Asi2600mc vs Asi533mm - AstroBin

Do you want an OSC or a mono workflow?
What targets are you aiming at and what does this mean in terms of pixel scale?
Are you forced to the ASI ecosystems or do you want to consider alternatives by other manufacturers with the same chip?
Does your current gear support the FoV of an APS-C chip?
Is your equipment able to handle the larger file sizes of the APS-C chip?

Both are very capable chips. With the IMX 571 chip you can cover the area of an IMX 533, won't work the other way round :-). So IMX 571 offers you a lot more flexibility in terms of FoV for the higher price.

I won't comment on the OSC vs. mono topic. In my opinion you should make up your mind between 2600 mm / 533 mm or 2600 mc / 533mc depending on what workflow you prefer.

I wouldn't consider the 294, it's a fairly old chip.

Clear skies
Wolfgang

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cosmoloaf

Apr 16, 2022

If you're used to mono at this point it might best to stick with that. Narrowband stuff is far more enjoyable to me with mono, but this comes down to preference as well as what objects you enjoy shooting the most. I would personally go for the 533MM as it's a straight upgrade in sensor tech. From there the only other mono camera I would consider as a serious upgrade is the 2600MM, but obviously requires a completely new filter set.

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vercastro

Apr 16, 2022

Honestly if you have the 1600 already I'd stick with it and save up for 2600MM.

Jim Matzger

Apr 16, 2022

Some folks are having issues with the 294mc.

SemiPro

IOTD Staff

Apr 16, 2022

I'd go with the 294mm. It's a massive upgrade over the 1600mm.

If you want a cleaner calibration then you can go for the 533mm if you don't mind the FoV loss.

vercastro

Apr 16, 2022

I'd go with the 294mm. It's a massive upgrade over the 1600mm.

If you want a cleaner calibration then you can go for the 533mm if you don't mind the FoV loss.

I want to be able to recommend 294mm, but it's really hard to with how bad the amp glow and calibration is.

SemiPro

IOTD Staff

Apr 16, 2022

I'd go with the 294mm. It's a massive upgrade over the 1600mm.

If you want a cleaner calibration then you can go for the 533mm if you don't mind the FoV loss.

I want to be able to recommend 294mm, but it's really hard to with how bad the amp glow and calibration is.

294MM users just need to be aware of the particulars around calibrating a sensor with amp glow. I find it calibrates the lights just fine with proper settings.

Arun H

Frequent contributor

Apr 16, 2022

I have taken multiple broadband and narrow band images with the 294MM. I guess I don’t understand the fuss around calibration. It calibrates fine - you need to make sure you use the same temperature and time for your calibration frames as the frames you are calibrating. I also use flats that are 4 seconds long, something I do even for my 2600MC Pro. For a long time I used the 1600MM. The lack of a AR coating on that sensor was a horrible deficiency. The 294MM has higher QE as well.

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Reg Pratt

Apr 16, 2022 · Edited: Apr 16, 2022

I had the 1600, went to a few 294mm and absolutely hated them, went to the 2600mm, QHY268, and Altair 26m and couldn't be happier. I don't feel its even fair to compare the IMX571 to past generation cmos sensors because its so much better. If the 2600 is in your budget and a good match for your image train theres no reason not to get it.

Marcelof

Apr 17, 2022

Reg Pratt:
I had the 1600, went to a few 294mm and absolutely hated them, went to the 2600mm, QHY268, and Altair 26m and couldn't be happier. I don't feel its even fair to compare the IMX571 to past generation cmos sensors because its so much better. If the 2600 is in your budget and a good match for your image train theres no reason not to get it.

I too initially replaced my 1600mm with the 294mm, now it's in a drawer and I'm back to the trusty and reliable ASI 1600mm.

There came a time when the 294's frames became simply impossible to calibrate (it developed a horrible center spot) and the hobby stopped being fun having to deal with that camera.

That said, as soon as the 533mm became available I pre-ordered it. If I had preferred a 4/3 format, yes. But I like being able to use the filters and FW I already have and not having to worry about potential tilt from larger formats and I can definitely live with its square format.

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Reg Pratt

Apr 17, 2022

Reg Pratt:
I had the 1600, went to a few 294mm and absolutely hated them, went to the 2600mm, QHY268, and Altair 26m and couldn't be happier. I don't feel its even fair to compare the IMX571 to past generation cmos sensors because its so much better. If the 2600 is in your budget and a good match for your image train theres no reason not to get it.

I too initially replaced my 1600mm with the 294mm, now it's in a drawer and I'm back to the trusty and reliable ASI 1600mm.

There came a time when the 294's frames became simply impossible to calibrate (it developed a horrible center spot) and the hobby stopped being fun having to deal with that camera.

That said, as soon as the 533mm became available I pre-ordered it. If I had preferred a 4/3 format, yes. But I like being able to use the filters and FW I already have and not having to worry about potential tilt from larger formats and I can definitely live with its square format.

I've owned the 183mc, 183mm, 3 x 294mc, then 4 x 1600mm. I sold the 1600 for 4 x 294mm. I had zero issues with any of those cameras until I got to the 294mm. All 4 of them suffered from horizontal banding that did not calibrate out and the amp glow never fully calibrated out. QHY and ZWO made statements about the banding saying you just need to turn the gain down but that never worked for me. I tried many different combinations of gain and offset. A hand full of people I know who also had the 294mm experienced the exact same issue as well as some people speaking up about it online so I know it wasn't just me. That experience really drove home "if it ain't broken don't fix it" because the 1600s were always good to me and never gave a single issue. I couldn't sell those 294 fast enough.

Even if I didn't have that experience though the 294 doesn't even belong in the same conversation as the imx533, 571, and 455. They're in a class of their own and imo there's zero reason to buy a camera with a previous generation sensor in it if one of the newer chips is in budget.

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Benny Colyn

Apr 17, 2022 · Edited: Apr 17, 2022

Depends on your scope. Can you use larger pixels without getting undersampled?

If yes, I'm pretty happy with my 294MM (got mine in oct 2020) but you do need to know how to properly calibrate its data (but again, properly calibrated the frames are great). I always shoot at gain 120, due to the HCG kicking in then. There's almost no reason to use anything other than that on the 294. The "unlocked bin 1 mode" sounds nice on paper, but I haven't had much use for it and it does bump you back to 12bit ADC and really hurts the full-well-capacity.

If you have the budget and don't want larger pixels than the 1600 for proper sampling an IMX571 is even better. But I'd stay away from the ASI2600 until all inventory with the oil leak problem has cleared the shelves (or perhaps even then, there's a couple of people who reported the issue even on "new batch - no more leak" cameras - dunno if that was reseller spiel). I'd look at the QHY, it seems to be free of this problem.

As for the 533MM - personally I don't think I like the square aspect ratio, but that may be PTSD from the 'gram. While it's probably a good sensor for its price, I'd wait and see for the camera ZWO builds around it - and if there's any more QC issues. I don't think I'd want to be an early adopter.

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SemiPro

IOTD Staff

Apr 17, 2022 · Edited: Apr 17, 2022

The 1600MM was a fine workhorse but if someone has the money to upgrade its definitely worth it.

Some fella on Cloudy Nights keeps track of the QE curves on the popular cameras and the 1600MM is just not able to keep up with even some of the sensors people are calling "old" here.

I notice the OP shoots with a RC6 on their profile so they would totally benefit from the bigger pixels on the 294MM. They also have a small refractor that could benefit from bin1 mode in dark skies.

I have taken multiple broadband and narrow band images with the 294MM. I guess I don’t understand the fuss around calibration. It calibrates fine - you need to make sure you use the same temperature and time for your calibration frames as the frames you are calibrating. I also use flats that are 4 seconds long, something I do even for my 2600MC Pro. For a long time I used the 1600MM. The lack of a AR coating on that sensor was a horrible deficiency. The 294MM has higher QE as well.

Arun hits the nail on the head here. The 294mm does not like short frames. The shortest calibration frames I take are 3 seconds long, but I prefer 6 seconds or more if I can. I've heard that if you use APP and leave the bad pixel mapping on, it messes up the calibration. It's stuff like that you have to watch out for; not only when you are taking the frames, but the options you choose in your stacking programs.

Not to discredit the negative experiences people have had with the 294MM but I have yet to have any calibration issues in bin1 or bin2 rocking subs up to 600 seconds long with serious amp glow that shows up on on the left, right, and bottom right of my sensor. Maybe it depends on the one you get?

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Paul Muller

Apr 17, 2022

2600MM and upgrade the filters - buy once, cry once.

Arun H

Frequent contributor

Apr 17, 2022

For those saying the 294MM has calibration issues, can they post specific examples of problems where they have seen it where proper procedure was followed - 4 second plus flats, no biases used anywhere, darks and flat darks taken at same time and temp as light and flat being calibrated? When done this way, so have not seen any calibration issues - I would say my gallery is proof of that.

Abhijit Juvekar

Topic starter

May 3, 2022

Thank you all for your detailed responses and experience sharing.
I think I will wait for some time until any new cameras come up by the winter or will keep 1600 for mono imaging and get 2600MC for OSC preferably from QHY or Altairastro, Orion brand since ZWO still suffering from that oil leak issue.

Eddie Bagwell

May 3, 2022

ZWO fixed the oil leak issue with new 2600s back in late December with the correct gaskets.

Well Written

James

May 4, 2022

This one is hard. I have both the 1600mm and 294mm. I even have a 533MC.

I feel like the 294mm is a nice upgrade over the 1600mm.. but I don't think its enough of an upgrade to justify the costs. My thinking is the 294mm is an alternative to the 1600mm if the choice was between the two for a purchase today.

As an upgrade from the 1600mm.. I think holding out for a 2600mm makes more sense. Ideally in another year or two we'll have a newer 4/3 sensor to choose from.

I wouldn't consider going mono to osc.. unless that's a deliberate move.. regardless of camera.

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Werner Stumpferl

May 4, 2022

I prefer the 294M, no problems with calibration, better rel. QE in red then 533M or 2600M (f.e. 656nm (Ha) with 294M is 75%, with 533/2600M is 60%)

Matthew Proulx

May 4, 2022 · Edited: May 4, 2022

Werner Stumpferl:
I prefer the 294M, no problems with calibration, better rel. QE in red then 533M or 2600M (f.e. 656nm (Ha) with 294M is 75%, with 533/2600M is 60%)

Ive owned the 294m and 26m and theyre not even comparable.
The flaws I could not overcome with the 294mm(and 294mc) were the sensor window and heavy banding. I have had multiples of these cameras and the same issue as have many others. I was glad to be rid of them.
The data with the 26m is so much cleaner.

You cannot compare QE of different pixel sizes.

Werner Stumpferl

May 4, 2022 · Edited: May 4, 2022

I only can tell you my experience with the 294M and I have no problems with banding nor calibration. You are right, the 2600 is much cleaner (I own a QHY268C) then the 294 but I have no issue with that.

QE is measured in %, not in photons per second per area. So you can compare smaller with bigger pixels because only the efficency is meassured (how much of the photons can be collected relative to the sum of incoming photons, f.e. 58% by 656nm with IMX571).

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andrea tasselli

Frequent contributor

May 4, 2022

Matthew Proulx:
You cannot compare QE of different pixel sizes.

Yes you can. In fact is the only parameter you can use to compare across different sensors. Sensitivity is another matter though.

I'd also agree with previous posters that the 294(MC) can be calibrated out quite nicely. I can't comment on the MM as I don't have it but I suspect there might be issues with dark calibration with NB filters.

Brandon Tackett

IOTD Staff

May 4, 2022 · Edited: May 4, 2022

I added a 294 MM to my equipment last fall in addition to my 1600 MM and 294 MC (all pro versions). I went back and fourth between the 2600 MM for several months but final decided on the 294 MM for several reasons:

First, I have a rasa8 that really is intended for 4/3 sensors or smaller. Second, I have 9.25 SCT that I wanted larger pixels for sampling at the 4.63 (2x2 binnig) for the larger scope and then ideal sampling at 2.315 (1x1 binning) at shorter focal length with the RASA8 at 400 mm FL. Even with the 12 bit mode at 1x1 binning, the results have been incredible. With the 1x1 mode as luminance layers, it double the resolution aka almost like a scope with 2x Focal length. I added a lum layer to M33 in this example and the difference is wild. I was able to resolve individual stars at in M33 with 400 mm FL in NGC 406 within M33. Definitely check out the difference between the prior non lum versions and the final image.

M33 Triangulum Galaxy 2022 Update Version L+Ha+OSC RASA8

Resolving Stars at 3 million light years!!! NGC 604 Nebula in M33 (Breaking the rule to compare to my backyard to HST Images)

When comparing single subs and fully calibrated subs between the 1600 and 294, the 294 MM wins every time with SNR as well as diminished star haloing on the same filters and no microlensing.

I have only had one image where I saw an horizontal banding that has been previously mentioned with my version HOO of Thors Helmet. This was my own doing where I had accidentally set the offset to 10 on NINA instead of an offset of 30 for my other images. Otherwise, I have had no banding issues or inability to calibrate out amp glow or dark current. You can see a similar length HOO image of the dolphin head has no banding.

Thor's Helmet NGC 2359 HOO

Dolphin Head Nebula SH2-308 HOO RASA8

With that said, my calibration process is: done with 30 subs for each calibration frame type in order to have adequate powered statistical sampling:
1) 30 darks cooled to same temp at lights
2) 30 6 seconds flats using neutral density film (longer flats to eliminate any banding present)
3) 30 6 second darks to calibrate out my flats (dark flats or flat darks) either way they are time equivalent darks to my flat length exposures.

Finally, I have really enjoyed 294 mm for short focal length at 280 mm and 135 mm focal length. Check out my last 6 months of wide field images in my gallery or on TAIC (THE AstroImaging Channel) this weekend as I talk about my experience with short focal length astrophotography.

A Winter Wonderland: The Rosette to the Christmas Tree Nebula (SHO Hubble Palette with Rokinon 135 mm)

Rokinon 135mm SHO Hubble Palette Heart and Soul Nebula: Complete Redo Edit after several incredibly helpful critiques

Lake Side Fire: Flaming Star, Tadpole, and Spider Nebula SHO (First Light Askar 400 at 280 mm)

I still really like and use my 1600 MM on other rigs while I use the 294 mm for my primary target any given night.
Hope that helps and Makes Sense!

-Brandon

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Lasse Skov

Oct 23, 2022

Brandon Tackett:
I added a 294 MM to my equipment last fall in addition to my 1600 MM and 294 MC (all pro versions). I went back and fourth between the 2600 MM for several months but final decided on the 294 MM for several reasons:

First, I have a rasa8 that really is intended for 4/3 sensors or smaller. Second, I have 9.25 SCT that I wanted larger pixels for sampling at the 4.63 (2x2 binnig) for the larger scope and then ideal sampling at 2.315 (1x1 binning) at shorter focal length with the RASA8 at 400 mm FL. Even with the 12 bit mode at 1x1 binning, the results have been incredible. With the 1x1 mode as luminance layers, it double the resolution aka almost like a scope with 2x Focal length. I added a lum layer to M33 in this example and the difference is wild. I was able to resolve individual stars at in M33 with 400 mm FL in NGC 406 within M33. Definitely check out the difference between the prior non lum versions and the final image.

M33 Triangulum Galaxy 2022 Update Version L+Ha+OSC RASA8

Resolving Stars at 3 million light years!!! NGC 604 Nebula in M33 (Breaking the rule to compare to my backyard to HST Images)

When comparing single subs and fully calibrated subs between the 1600 and 294, the 294 MM wins every time with SNR as well as diminished star haloing on the same filters and no microlensing.

I have only had one image where I saw an horizontal banding that has been previously mentioned with my version HOO of Thors Helmet. This was my own doing where I had accidentally set the offset to 10 on NINA instead of an offset of 30 for my other images. Otherwise, I have had no banding issues or inability to calibrate out amp glow or dark current. You can see a similar length HOO image of the dolphin head has no banding.

Thor's Helmet NGC 2359 HOO

Dolphin Head Nebula SH2-308 HOO RASA8

With that said, my calibration process is: done with 30 subs for each calibration frame type in order to have adequate powered statistical sampling:
1) 30 darks cooled to same temp at lights
2) 30 6 seconds flats using neutral density film (longer flats to eliminate any banding present)
3) 30 6 second darks to calibrate out my flats (dark flats or flat darks) either way they are time equivalent darks to my flat length exposures.

Finally, I have really enjoyed 294 mm for short focal length at 280 mm and 135 mm focal length. Check out my last 6 months of wide field images in my gallery or on TAIC (THE AstroImaging Channel) this weekend as I talk about my experience with short focal length astrophotography.

A Winter Wonderland: The Rosette to the Christmas Tree Nebula (SHO Hubble Palette with Rokinon 135 mm)

Rokinon 135mm SHO Hubble Palette Heart and Soul Nebula: Complete Redo Edit after several incredibly helpful critiques

Lake Side Fire: Flaming Star, Tadpole, and Spider Nebula SHO (First Light Askar 400 at 280 mm)

I still really like and use my 1600 MM on other rigs while I use the 294 mm for my primary target any given night.
Hope that helps and Makes Sense!

-Brandon

Thanks for this Brandon. Makes my choice for the 294 mm easier. And thank you for the information about the calibration frames.

Well Written

Which will be a worthy upgrade over 1600MM-PRO considering above mentioned reasons?