lunt ls50 v ls60 v DayStar Solar Scout SS60-DS 60mm H-Alpha Solar Telescope

[iwols]

hi all apart from the price does anyone have any comments on these 3 for imaging thanks

Edited March 22, 2022 by iwols

[vlaiv]

For imaging, if price is not parameter - LS60:

1. 60mm > 50mm so more resolution with 60mm obviously

2. SS60-DS is F/15.5 scope. For imaging Ha wavelength at F/15.5 - you need 5.084um pixel size for optimum sampling. With 60mm scope, critical sampling is at 1.128"/px. Sun is roughly 1800" so that translates into 1596px diameter of the sun. This means that you need about 8.2mm high sensor if you want to capture full solar disk.

You will be hard pressed to find fast mono cmos that is about 5um pixel size and 8.2mm or more in height. Closest thing is mono ASI183mm with binned pixels - that is 4.8um binned pixel size and 8.8mm height

Such camera will have 3.2e of read noise at best (by itself it has 1.6e read noise but you will need to bin x2 - and that doubles the read noise).

Lunt 60 is F/7 scope. With F/7 scope, needed pixel size is 2.296um pixel size, so 2.4um pixel size fits nicely. With 1596px at 2.4um you need sensor that is 4mm in height to capture full solar disk.

ASI178mm has needed specs, is much cheaper than ASI183, has lower read noise at 1.4e (compared to 3.2e of binned ASI183) - you avoid the need for software binning, and it has slightly faster fps than ASI183 at ROI size needed to capture full disk.

 

 

 

[Highburymark]

Agree - LS60. For visual, I’d prefer a double stacked LS50 to a single stacked LS60, but for imaging you can counteract the lower contrast of surface features with just one etalon through post processing to a degree. You may be fortunate and get a really good single stack which performs more like a double stack, but it’s something of a lottery. 

Must say I don’t understand the Solar Scout design at all. Quarks operate best at F/30 and over, so the superfast Solar Scout seems built to produce a wide bandwidth and lower contrast. And the fact that the quark/etalon is not detachable (though some enterprising owners have succeeded in separating it and using it more like a real Quark) means you can’t slow down the system with an extra extender or barlow. The fact that it’s advertised as having ‘double stack’ performance is marketing nonsense.

[Roy Challen]

On 23/03/2022 at 12:32, Highburymark said:

 

Must say I don’t understand the Solar Scout design at all. Quarks operate best at F/30 and over, so the superfast Solar Scout seems built to produce a wide bandwidth and lower contrast. And the fact that the quark/etalon is not detachable (though some enterprising owners have succeeded in separating it and using it more like a real Quark) means you can’t slow down the system with an extra extender or barlow. The fact that it’s advertised as having ‘double stack’ performance is marketing nonsense.

I made an aperture mask (30mm approx, effectively f/30 or thereabouts), this greatly improved contrast. Resolution is very slightly lower but not enough to make an impact for full disc visual observations - to my eyes at least. Also for visual, eyepiece choice can make a huge difference. The recommended Televue 25mm plossl is easily outperformed by both Vixen 30 and Baader 32 plossls, very much so in the latter.

Sorry, just read the OP, this thread is about imaging, disregard my comments in that respect.

Edited March 25, 2022 by Roy Challen

[Highburymark]

Interesting Roy - think your comments are still relevant as a lot of people consider the Solar Scout for imaging, and stopping it down to 30-40mm is a good option. It’s just odd why the original design was so fast.

[iwols]

just need to find a LS60 at a reasonable price now thanks guys😬