Is a OSC Suseptable to Light Pollution Same as SLR?

[PottyMonster]

Hi All, I'm over-analysing various astro camera options. I'm in a fairly light polluted bortle 5 (accoridng to lightpollutionmaps.info) area currently using a old un-modified Canon APSC camera, however I'd like to improve the quality of my images.... I'm not looking to challenge hubble, however I'd like my future investment not to be a total waste of money. My concern is getting a new OSC camera (such as a ZWO ASI294MC-Pro) won't actually produce results significantly better than what I already have, as in it'll be just as susseptable to light pollution; although granted the extra sensitivity of a dedicated astro camera will capture the images faster. While I could stretch the budget to a mono camera (e.g. ASI 294MM-PRO or ASI 1600MM-PRO) the cost of additional filters pushes this beyond my current budget at the moment. I could save up though so not ruling this out as an option if the advice I get is it's the only answer to resolving the light pollution limitation...other than moving!

As a side, I do already own a Optolong L-eXtreme dual band filter which I could use with a OSC and a Sky's the Limit Light pollution HT CLS 2.00.

My setup is a Skywatcher Explorer 200PDS on a HEQ5 mount fully guided and tacking well.

Any advice greatly appreciated.

[Adam J]

1 hour ago, PottyMonster said:

Hi All, I'm over-analysing various astro camera options. I'm in a fairly light polluted bortle 5 (accoridng to lightpollutionmaps.info) area currently using a old un-modified Canon APSC camera, however I'd like to improve the quality of my images.... I'm not looking to challenge hubble, however I'd like my future investment not to be a total waste of money. My concern is getting a new OSC camera (such as a ZWO ASI294MC-Pro) won't actually produce results significantly better than what I already have, as in it'll be just as susseptable to light pollution; although granted the extra sensitivity of a dedicated astro camera will capture the images faster. While I could stretch the budget to a mono camera (e.g. ASI 294MM-PRO or ASI 1600MM-PRO) the cost of additional filters pushes this beyond my current budget at the moment. I could save up though so not ruling this out as an option if the advice I get is it's the only answer to resolving the light pollution limitation...other than moving!

As a side, I do already own a Optolong L-eXtreme dual band filter which I could use with a OSC and a Sky's the Limit Light pollution HT CLS 2.00.

My setup is a Skywatcher Explorer 200PDS on a HEQ5 mount fully guided and tacking well.

Any advice greatly appreciated.

What targets are you hoping to shoot? The 200PDS suggests galaxies. Personally if you are wanting to image nebula then I think you need a smaller scope. Something like the 130PDS or the new 150mm F4 SW newtonian.

Beyond that I would not reccomend the ASI294mc pro due to difficulties calibarating images. I own the ASI1600mm pro and its a great camera, the 294mm-pro is an unknown to me but to be honest the issues with the 294mc would put me off. Perhapse the issue with mono is that you are aiming too high with the camera, what about the 533mm or the 183mm both are inexpsnsive ways to get into mono imaging. After that all you will need is some LRGB filters if you intend to image galaxies.

You can use duel band filters with OSC cameras these days that will mitigate allot of light polution but lets be clear, you are still better off with a mono camera in that circumstance.

 

Adam

Edited August 2, 2022 by Adam J

[Lee_P]

I use an OSC camera from a Bortle 8 city centre (and have a whole website about it, with lots of example photos here, and you may find this article particularly useful) -- your Bortle 5 skies are much darker so it's possible for you too. FYI I use a ZWO ASI2600MC-PRO camera, plus Optolong L-eXtreme filter. I consider that filter, or one similar, as a must for narrowband targets (specifically hydrogen-rich nebulae). For broadband targets such as galaxies and star clusters, I don't use any filters. In general, when imaging from light-polluted skies, aim for long total integration times to get decent signal-to-noise ratio. 

Edited August 2, 2022 by Lee_P

[geeks]

Yeah as someone else who spent a large amount of time shooting from a B7/8 the step up from an unmodded-DSLR to a OSC astrocam with a good filter the difference was... well.... night and day. I keep more than one filter depending on what I am shooting. I have an IDAS LPS D2 and also an Altair Triband. 

[PottyMonster]

15 hours ago, Lee_P said:

I use an OSC camera from a Bortle 8 city centre (and have a whole website about it, with lots of example photos here, and you may find this article particularly useful) -- your Bortle 5 skies are much darker so it's possible for you too. FYI I use a ZWO ASI2600MC-PRO camera, plus Optolong L-eXtreme filter. I consider that filter, or one similar, as a must for narrowband targets (specifically hydrogen-rich nebulae). For broadband targets such as galaxies and star clusters, I don't use any filters. In general, when imaging from light-polluted skies, aim for long total integration times to get decent signal-to-noise ratio. 

Wow, Your website is really good!....extremly helpful and amazing pictures. Thanks for sharing, Hope you have a lot of success with it. I'll be checking back regularly!  How I wish I could afford a ASI2600MC-PRO!

[Clarkey]

7 hours ago, PottyMonster said:

How I wish I could afford a ASI2600MC-PRO

Rising Cam IMX571. Pretty much the same camera but half the price. Slight gamble with warranty but much better value. There other manufacturers selling it under a different name at low prices too.

[wimvb]

Cmos astro cameras are more sensitive than SLR. You also mention that you are interested in a cooled camera. This will make the calibration process easier, especially since the ASI294 has amp glow that requires careful calibration. If I were you, I would go for a newer generation camera that doesn't have amp glow.

Bortle 5 is not that light polluted, but if you are concerned that it may be a problem, you should look into mono imaging. RGB filter are generally designed to suppress conventional sources of light pollution, sodium and mercury lights.

If I were in the market for a new camera, I would probably add an osc to my collection (Bortle 4 skies). But I already have mono cameras.

[Adam J]

4 hours ago, Clarkey said:

Rising Cam IMX571. Pretty much the same camera but half the price. Slight gamble with warranty but much better value. There other manufacturers selling it under a different name at low prices too.

I dont think that the warranty itself is a gamble more the time taken to send it for repair. But to be honest others have had good experiences in this regard none the less. 

[PottyMonster]

17 hours ago, Clarkey said:

Rising Cam IMX571. Pretty much the same camera but half the price. Slight gamble with warranty but much better value. There other manufacturers selling it under a different name at low prices too.

Thanks! I'll check it out.

[PottyMonster]

On 03/08/2022 at 07:37, Clarkey said:

Rising Cam IMX571. Pretty much the same camera but half the price. Slight gamble with warranty but much better value. There other manufacturers selling it under a different name at low prices too.

If I was to hypothetically get a Rising Cam IMX571 ...what would be the difference between the AR glass and IR Cut filter versions?  ... from what I understand if I didn't get the IR filter I'd need to add one anyway.... so I'm not sure what the benefit would be of not having it? Is the IR cutoff near the HA wavelength? .....and I assume there wouldn't be any problems using this camera with APT? 

[ONIKKINEN]

8 minutes ago, PottyMonster said:

If I was to hypothetically get a Rising Cam IMX571 ...what would be the difference between the AR glass and IR Cut filter versions?  ... from what I understand if I didn't get the IR filter I'd need to add one anyway.... so I'm not sure what the benefit would be of not having it? Is the IR cutoff near the HA wavelength? .....and I assume there wouldn't be any problems using this camera with APT? 

The UV/IR cut filter in the RisingCam advertises a cutoff of 650nm in the red end, so you would get absolutely no H-alpha in the image at all. That is a terrible thing for an astrocam, so you will need to get the AR filter version and then install an additional UV/IR cut filter somewhere in your imaging train.

Now whether you need one with a newtonian is not as obvious as with a refractor (because with refractors you would get extreme chromatic aberration from the infrared, whereas mirrors reflect everything equally), but its a good idea to get one anyway because you may get some reflection issues from the Infrared wavelengths leading to halos around stars, and you will definitely get an extra reddish-pinkish hue to everything and find it difficult to colourbalance things to a realcolour end result (because you imaged beyond normal colours).

In short, AR glass window and an extra UV/IR filter somewhere is the way to go.

[PottyMonster]

1 minute ago, ONIKKINEN said:

The UV/IR cut filter in the RisingCam advertises a cutoff of 650nm in the red end, so you would get absolutely no H-alpha in the image at all. That is a terrible thing for an astrocam, so you will need to get the AR filter version and then install an additional UV/IR cut filter somewhere in your imaging train.

Now whether you need one with a newtonian is not as obvious as with a refractor (because with refractors you would get extreme chromatic aberration from the infrared, whereas mirrors reflect everything equally), but its a good idea to get one anyway because you may get some reflection issues from the Infrared wavelengths leading to halos around stars, and you will definitely get an extra reddish-pinkish hue to everything and find it difficult to colourbalance things to a realcolour end result (because you imaged beyond normal colours).

In short, AR glass window and an extra UV/IR filter somewhere is the way to go.

Perfect explanation, thanks for the promt reply.

[Clarkey]

I had just started a reply. Beat me to it!

650nm is a very low cut off point. Not only loosing Ha and SII but half the red spectrum. Strange for an astrocam?!