White light imaging camera recommendations

[heliumstar]

Looking for SGL wisdom. Want to try some white light imaging - full disk. Scope is 115/805 with a Herschel wedge. Something that will look good printed on let's say at least 60x40.

585 sensor with reducer gives full disk but I would prefer something wider and to also be useful for planetary imaging and some light EAA. 183 sensor is a little bit 'old' now. Any modern equivalent? Also not sure about mono or colour.

[Elp]

Mono is better for solar imaging, the 183 is capable but its FPS isn't designed for planetary, but you need to decide what capture software you're going to use too.

[heliumstar]

2 hours ago, Elp said:

Mono is better for solar imaging, the 183 is capable but its FPS isn't designed for planetary, but you need to decide what capture software you're going to use too.

Software...have no preference here. Will go with collective SGL wisdom if there are any recommendations. Happy to use anything although slight preference to using something on Linux. Ok with going with all in one solutions from ZWO or anything else.

Edited Wednesday at 14:46 by heliumstar

[vlaiv]

3 hours ago, heliumstar said:

Something that will look good printed on let's say at least 60x40.

I'm guessing that you mean 60" x 40" there or 60 cm x 40 cm?

In any case, what you can expect from 115mm scope would be max of 0.36"/px as far as sampling goes or about 1800" / 0.36 = ~5020px across the disk (if disk is 30' angular size).

If you print that at say 150 dpi - you get solar disk of 5020/150 = 33.46" which should fit nicely on 60" x 40".

I'd go with ASI183 mono there and wedge and Baader solar continuum filter. Although FPS is not high on ASI183 - it does not matter as you can image for longer periods of time, not just minutes.

Scope is natively F/7 and you want it to be at least F/10 to F/12 for pixel size of 2.4um of ASI183, so x1.5 barlow - barlow element so you can adjust distance between it and sensor.

You'll probably need to take two passes as sensor is not large enough to cover whole solar disk in one go. It has enough width but not enough height so two panel mosaic.

[heliumstar]

@vlaiv I mean 60 cm x 40 cm.

Ideally I would like to image without barlow but of course not a deal breaker. Any other sensors or anything else that would be suitable?

[Elp]

You can still image without the barlow but I believe your sampling will be affected.

[vlaiv]

12 minutes ago, heliumstar said:

@vlaiv I mean 60 cm x 40 cm.

Ideally I would like to image without barlow but of course not a deal breaker. Any other sensors or anything else that would be suitable?

Just run the math again and see what would be suitable.

As far as imaging and sensor spec go - you want couple of things.  It is basically the same as planetary imaging with few differences (more like lunar than anything else).

1. Mono is better than color for white light as you won't be capturing color information

2. You want good QE and decent frame rate, and low read noise

3. Adjust your F/ratio according to pixel size (or your target image size).

4. Look for the sensor that will give you imaging in one go rather than mosaics as it is easier.

Sun will provide you with a lot of light so you can keep exposure very short. You don't need very high transfer rates as you can afford to image for longer than just few minutes. Low read noise helps but is not essential as there will be plenty of light so signal will be strong.

If you want to go for 60x40cm and want to go with 300dpi print - let's say that sun diameter in the image will be 30cm to have some room around - that will mean that sun needs to be 30/2.54 * 300 = 3540px wide.

Since max solar diameter is around 1950 arc seconds max (32' 32" when largest and 31' 27" smallest) this leads to 1950 / 3540 = 0.55"/px, which for 805mm of focal length gives 2.15px.

Again, 2.4um pixel size seems like a good fit. Whole disk will be somewhat smaller and you won't need to use for 300dpi and 60cm x 40cm. ASI183 still seems like obvious choice - but this time, Sun will fit onto sensor in single go.

For 60x40 print  - my choice would be 183 mono sensor - no barlow and I would crop / scale image for 300dpi print in the end to frame the Sun nicely.

 

[bosun21]

The 183 will be a poor choice for imaging the planets though due to the relative slow frame rate.

[vlaiv]

19 minutes ago, bosun21 said:

The 183 will be a poor choice for imaging the planets though due to the relative slow frame rate.

What would be frame rate on 183 on 640x480 ROI for example?

[bosun21]

Just now, vlaiv said:

What would be frame rate on 183 on 640x480 ROI for example?

I can't recall the figure off hand but it was nowhere near the 150fps I needed for the planets. My 585 isn't the fastest planetary camera but it will still give me 180+ FPS.

[bosun21]

10 minutes ago, vlaiv said:

What would be frame rate on 183 on 640x480 ROI for example?

On looking at the specs for the 183 it looks not as slow as i believed. It may get up there with the small ROI as you suggested. Perhaps @Elp can chime in as I believe he owns a 183 .

[vlaiv]

3 minutes ago, bosun21 said:

I can't recall the figure off hand but it was nowhere near the 150fps I needed for the planets. My 585 isn't the fastest planetary camera but it will still give me 180+ FPS.

According to ZWO website:

I don't see why wouldn't it give 180+ on smaller ROI if it gets 100+ FPS on 1280x720 which has x3 more pixels to read out and transfer than 640x480.

 

[vlaiv]

Just now, bosun21 said:

On looking at the specs for the 183 it looks not as slow as i believed.

I don't think that any of of the cmos sensors are particularly slow. They are just limited by USB bandwidth and if one is using and utilizing USB3.0 and using ROI - they can get good speeds.

[vlaiv]

I found actual FPSs for ASI183 in its manual:

It can achieve good speeds with ROI - not the best, but good enough.

[bosun21]

1 minute ago, vlaiv said:

I don't think that any of of the cmos sensors are particularly slow. They are just limited by USB bandwidth and if one is using and utilizing USB3.0 and using ROI - they can get good speeds.

I am looking at getting a camera for EAA with a larger fov than my 585. Do you think a 183 would be a good choice for this? My scopes would be 10" go to dobsonian f4.8 and my 120ED with a 0.85x reducer for f6.37.

[Elp]

2 hours ago, bosun21 said:

On looking at the specs for the 183 it looks not as slow as i believed. It may get up there with the small ROI as you suggested. Perhaps @Elp can chime in as I believe he owns a 183 .

Hence my query about controller. With an Asiair the max video resolution is 1920 x 1080 if I remember right, it doesn't deliver the FPS as per the tables. Using asistudio on a laptop however it does deliver faster rates, I was planning on using it for full disk HA solar imaging through my quark with a 200mm guidescope.

[vlaiv]

2 hours ago, bosun21 said:

I am looking at getting a camera for EAA with a larger fov than my 585. Do you think a 183 would be a good choice for this? My scopes would be 10" go to dobsonian f4.8 and my 120ED with a 0.85x reducer for f6.37.

I think that best EAA camera is one that is large and has low read noise.

If you can get even larger sensor than 183 - then get that one, otherwise - 183 will be good enough.

For EAA you want "sensitivity" and this means large pixel size coupled with large aperture. You have scopes with enough aperture, but problem is to find camera with large pixels. Most modern cameras have small pixels - and this is where binning comes to the rescue.

Drawback of the binning is that you reduce number of pixels - and that is why you need large camera.

Say you want to go with 2"/px with your 10" dob for EAA. That will give you really fast setup. FL of dob is 1220mm and in order to get 2"/px you need pixel size that is ~12um.

You simply can't get that easily with cmos - but if you use ASI183 for example - that will be bin 5x5. Now instead of 5496×3672 you get ~1100 x 734px - not bad - but larger sensor would let you bin and still get a lot of pixels - or decently sized image.

[Elp]

I find my 183s adequate enough. The 533 is a sort of square equivalent (183 is approx 13 x 9mm, 533 is 11 x 11) so with the 533 you gain in height but loose the width and either will be a significant change from the 585 which I believe is 11 x 6 which I found too "low" in height (I had the 485), it is however a good in between camera for both planetary and DSO.

Going up would be the 294 at 19 x 13 which does give a significant FOV change, BUT, the OSC is a funny sensor, maybe okay for EAA, not so much for long exposure DSO.

Above that then they start to become more significantly expensive. A cheaper option maybe an APSC mirrorless camera but you'll get the QE drop and added noise due to thermals.

The 533 would be good I believe though it's only 3000 x 3000 pixel res. The 183 at long FL/higher aperture does suffer in pixel response at bin1, but the benefit is it has the resolution to support multiple bin.

[vlaiv]

3 minutes ago, Elp said:

Going up would be the 294 at 19 x 13 which does give a significant FOV change, BUT, the OSC is a funny sensor, maybe okay for EAA, not so much for long exposure DSO.

I agree that 294 is not the best choice due to issues, but I think there is alternative - at least for EAA with OSC sensor.

https://www.altairastro.com/altair-hypercam-269c-colour-camera---tec-cooled-1097-p.asp

That camera is rarely mentioned  - but I think it has very good specs for EAA with above approach.

There is also fan cooled version - which is somewhat cheaper:

https://www.altairastro.com/altair-hypercam-269c-colour-camera----fan-cooled-7949-p.asp

[Elp]

That 269 seems to have decent specs.

[Elp]

Maybe for OP the Player One Apollo M (imx432)?