ZWO 533MC or 2600MC

[RugbyRene (Rene)]

Hi all,

Looking for some sage advice on a camera for a new wide-field setup I’m building. I’ve got an Askar FRA400 which I will use in native 400mm mode and with a 0.7 reducer. I’m looking at a camera for this setup and am looking at a 2600MC (which I have for my main rig) or a much cheaper 533MC. I’m leaning towards the 533MC as the specs look good and I can’t justify the extra almost $2000 in cost, but the 2600 is 16-bit vs the 533 which is 14-bit.

Looking at Astronomy Tools the 533 will introduce a fair degree of under-sampling but am wondering if this is not that important at 400 or 280mm.

So am I better off going with the cheaper 533?

Rene

[neilbarber (Neil)]

is it not just under sampled when using the reducer. Have the 533mc pro and love it. Haven't had to use calibration frames (maybe i should) and happy with my results (Z61ii + flattener).

[Startrek (Martin)]

I wouldn’t be too concerned about 14bit compared to 16bit
Just stack more shorter subs with the 533MC to fully utilise the dynamic range of the sensor
The 533MC performance charts attached are excellent ( as with the 2600MC )
The HGC mode kicks in at Gain 100 for both cameras which provides low read noise at good dynamic range
Dark current for both cameras is super low cooled to -10C , no need to go lower

533MC and 2600MC have same size pixel pitch at 3.76uM so image scale is similar but the 533MC 1” sensor size is somewhat restrictive depending on your resultant FOV from your image train and type of target areas for imaging
You really can’t go wrong with either camera but there’s a huge cost difference.

Good luck

Martin

[gregbradley]

To pick a camera I suggest you work it backwards.

Work out what type of image you want to take and then which camera would give that field of view.

There is a tool for that I have found very useful as it gives resultant sample images that a particular setup would generate.

https://new-astronomy-ccdcalc.softwa...ormer.com/1.5/

Greg.

[The_bluester (Paul)]

I changed to my 2600 from an ASI294 partly due to the 16 bit conversion. I like to do long exposures and expected (And confirmed more or less the first time I used it) that it would/should produce better star colour profiles.

Ignoring the 14 bit versus 16 bit question, I know the 2600 costs a lot more but if you are doing a widefield rig the 2600 has a much larger sensor. The combined pic attached is what field of view I would get using my Stellarvue SVX80 without reducer, with the sensor size of the 533 versus the 2600.

[RugbyRene (Rene)]

Originally Posted by The_bluester

I changed to my 2600 from an ASI294 partly due to the 16 bit conversion. I like to do long exposures and expected (And confirmed more or less the first time I used it) that it would/should produce better star colour profiles.

Ignoring the 14 bit versus 16 bit question, I know the 2600 costs a lot more but if you are doing a widefield rig the 2600 has a much larger sensor. The combined pic attached is what field of view I would get using my Stellarvue SVX80 without reducer, with the sensor size of the 533 versus the 2600.

Yes I did the same thing in Telescopius and have decided to go with the 2600. Just have to get it past the financial committee.

[gregbradley]

Yeah I think that is the right choice.
It's a common decision with astro gear. Do you get the cheaper item that isn't quite what you want? Then you later sell it at a loss in order to get the one you should've gotten even if you had to wait longer to get it.

You end up spending something like 50% more with that approach.
Unless you are a rare type of person who is happy with what they got and don't aspire to get better gear as you progress in the hobby.

At least that has been my experience.

Greg.

[The_bluester (Paul)]

Originally Posted by RugbyRene

Yes I did the same thing in Telescopius and have decided to go with the 2600. Just have to get it past the financial committee.

Just a pity. If I could afford the move to a second mono ASI2600 (I have one of each flavour now) I could sell you a secondhand OSC!

That looks like a job for next year if I am lucky, by the time I pay for the cam upgrade (See Greg's comment about ending up spending 50% more over time!) and then filters.

[Leo.G (Leo)]

Originally Posted by gregbradley

To pick a camera I suggest you work it backwards.

Work out what type of image you want to take and then which camera would give that field of view.

There is a tool for that I have found very useful as it gives resultant sample images that a particular setup would generate.

https://new-astronomy-ccdcalc.softwa...ormer.com/1.5/

Greg.

That looks like a very handy link except it comes up with a virus warning when trying to download the exe file.
It pops up with a link to download the program directly then comes up with a server error.
I was keen to have a look, don't know if that's going to happen though.
The link is dead or appears to be,

[rmuhlack (Richard)]

this website provides similar functionality to the software tool that Greg linked to

https://astronomy.tools/calculators/field_of_view/

their ccd suitability calculator is also helpful in evaluating how well suited a scope/camera combination is to different seeing conditions.

https://astronomy.tools/calculators/ccd_suitability

[rmuhlack (Richard)]

btw, I have a QHY533C which I have paired with a Sharpstar 130HNT (FL = 364mm, f2.8) and I think this image scale (2.13 arcsecs per pixel) works well for many targets. The 2600 and 533 have the same pixel size (3.76 micron) and so the image scale (arcsecs per pixel) will be the same for both sensors, you're just getting a wider field of view with the 2600 (albeit at a much higher cost, and likely a larger (or more deformed) spot size in the image corners compared to the 533)

[Crater101 (Warren)]

Originally Posted by gregbradley

It's a common decision with astro gear. Do you get the cheaper item that isn't quite what you want? Then you later sell it at a loss in order to get the one you should've gotten even if you had to wait longer to get it.

You end up spending something like 50% more with that approach.

My world, right there!



FWIW, I agree with what Greg said below.