Time to switch cameras?

[ste7e]

Hello helpful folk

I'm in a bit of a quandary and need some help from the knowledgeable...

I currently use my beloved Nikon D600 for astro work as well as daytime photography.  The camera is unmodified.

I struggle with light pollution.  I have a Neodymium filter - doesn't seem to help a great deal.  Can't get a decent shot of the Veil nebula, for example.

I also struggle with noise gradients in my shots.  I feel that pushing my pictures to get the meagre detail that's in them to come out, I end up batting the nasty orange-ness of the LP and the noise.

What I'm wanting is to get more detail out of my shots.

What I'm trying to decide is whether to get another camera.  My budget for astro is not limitless (in fact, it's quite limited by the standards of most on these forums).

I could stretch myself and go way up market, for me, and get a QHY8. But, would that really help me when it comes to my problem - OK, it'd mean I can get nice long low-noise exposures.  But wouldn't that just mean that I'd hit the LP wall?  So, I'd end up taking shorter exposures and be no better of with a smaller FOV?

I feel if I did spend £1000 on a QHY8 I'd need to spend another few hundred on filters to go into NB imaging.

So, the other, much more gentle on the wallet option would be to get a second-hand DSLR and mod it to full-spectrum (using the IR-cut properties of the Neodymium filter).  I was thinking along the lines of a Canon 600D.

Would that be a positive or a negative move for me?  Would the 600D be even noisier than my D600?  Would the smaller sensor be a problem?

Any help would be great.

This is what consider my best shot from my current set up

 

[swag72]

Narrowband imaging is great for combating light pollution, but it works with mono cameras and not the One Shot Colour (OSC) camera such as the QHY8. 

If you spend some time with a FOV calculator such as this one you can put in a host of camera and scope combos along with targets and so you can get a feel for sensor size. No one but you can decide if a small sensor would be a problem.

I rate mono camera's - They are versatile in that you can do narrowband imaging and so make the most of the clear skies. With NB you can ....almost... image when the moon is full, but I found that with a OSC once the moon was around at all then it was useless. So for me that meant that it was unusable for 2 weeks of the month .... guess when the clear nights come   

[ronin]

I would say that ultimately you will (may) have to look seriously at the mono and NB aspect. That is where the impressive images seem to come from. Will say I can see the advantage of OSC, basically less time involved. Which in the UK equates to more available opertunities.

I am not sure the usefulness of a DSLR as you need to purchase one, then have it modified - thinking that the money involved there can go to a reasonable ZWO now. Part of this comes from a serious imager that made a comment on a DSLR for AP once. A simple attitude is that we can use a DSLR but really they were never designed for AP and as such may not be the best instrument especially at the lower cost end. We are making it do several things that it just was not intended for. Eg. anything over a 1 second exposure is expecting to have a noise reduction exposure for thermal noise generation, when in AP are exposures less then 1 second?

Another DSLR if modified will allow you additional wavelengths, not necessarily better image as in a awful way it is "just" another DSLR, although that may depend on the wave lengths that your present in-camera filter allows. A D60 seems to pass about 20 to 25% of the Ha through to the sensor. A modified camera would let through more Ha, but likely show most improvement in the SII wavelength.

The way to remove light pollution is really again mono and NB. Still agree the time requirement extends by a lot. And the ultimate cost.

I think it comes down to : Where do you want to go to in terms of imaging. I really think this is what needs answering primarily.

[RichLD]

+1 for mono camera and NB. 

[ste7e]

1 hour ago, swag72 said:

Narrowband imaging is great for combating light pollution, but it works with mono cameras and not the One Shot Colour (OSC) camera such as the QHY8. 

If you spend some time with a FOV calculator such as this one you can put in a host of camera and scope combos along with targets and so you can get a feel for sensor size. No one but you can decide if a small sensor would be a problem.

I rate mono camera's - They are versatile in that you can do narrowband imaging and so make the most of the clear skies. With NB you can ....almost... image when the moon is full, but I found that with a OSC once the moon was around at all then it was useless. So for me that meant that it was unusable for 2 weeks of the month .... guess when the clear nights come   

Thanks for this.  I really hadn't realised that nb was only feasible on mono cameras! Feel a bit stupid about that. 

So that means filter wheel and an expensive set of colour filters... i can feel my wallet shrivel at the thought...

[ste7e]

7 minutes ago, ronin said:

I would say that ultimately you will (may) have to look seriously at the mono and NB aspect. That is where the impressive images seem to come from. Will say I can see the advantage of OSC, basically less time involved. Which in the UK equates to more available opertunities.

I am not sure the usefulness of a DSLR as you need to purchase one, then have it modified - thinking that the money involved there can go to a reasonable ZWO now. Part of this comes from a serious imager that made a comment on a DSLR for AP once. A simple attitude is that we can use a DSLR but really they were never designed for AP and as such may not be the best instrument especially at the lower cost end. We are making it do several things that it just was not intended for. Eg. anything over a 1 second exposure is expecting to have a noise reduction exposure for thermal noise generation, when in AP are exposures less then 1 second?

Another DSLR if modified will allow you additional wavelengths, not necessarily better image as in a awful way it is "just" another DSLR, although that may depend on the wave lengths that your present in-camera filter allows. A D60 seems to pass about 20 to 25% of the Ha through to the sensor. A modified camera would let through more Ha, but likely show most improvement in the SII wavelength.

The way to remove light pollution is really again mono and NB. Still agree the time requirement extends by a lot. And the ultimate cost.

I think it comes down to : Where do you want to go to in terms of imaging. I really think this is what needs answering primarily.

Another vote for mono and nb, then. 

Thanks for the helpful info. [One of the best things about this astro lark is the quality of advice and the time people are willing to put into helping others on the forms. ]

I think I'm going to have to seriously consider the expensive option. 

The extra time that mono needs is a concern, too, though.  I already struggle with lack of usable sky time.

[swag72]

Spend some time with the FOV calculator I linked to..... A great starter camera to mono CCD imaging is a Sony 285 chip that is in the Atik 314L+ for example (I'm thinking that these come up second hand now for about £500......) Its a hellishly small chip though when compared to the DSLR but many imagers have cut their teeth with this camera and its a belter. 

There is also the ASI1600 that you can look at - There's a big thread on the forum if you do a search..... look at the images and make up your own mind. It's a new CMOS sensor setup that none of the other main manufacturers (apart from QHY I think) have put it into their line up. The ASI1600 uses a much larger chip than the Sony 285 (almost akin to the DSLR) The larger the chip, the less tolerance a scope has in the corners and then you start needing field flatteners - There's a lot to be said for the ease of a small chip

Hope that helps. 

[ollypenrice]

36 minutes ago, ronin said:

I would say that ultimately you will (may) have to look seriously at the mono and NB aspect. That is where the impressive images seem to come from. Will say I can see the advantage of OSC, basically less time involved. Which in the UK equates to more available opertunities.

 

I've disagreed with you before on this one, Ronin. OSC is slower than mono, not faster. This really isn't hard to understand, as I'll try to demonstrate below.

ANY colour filter blocks about 2/3 of the light and EVERY pixel of on OSC camera has a colour filter in front of it ALL the time. So looking at the incoming light let's shoot for 4 hours in an OSC.

Ist hour, 1/3 of all lght captured.

2nd hour, ditto.

3rd hour ditto.

4th hour ditto.

Total, 4 x 1/3 of the total light captured.

Now 4 hours in LRGB using a mono camera.

1st hour, red, 1/3 of all light.

2nd hour, green, ditto.

3rd hour, blue, ditto.

4th hour, luminance  3/3  of all light captured.

Total 6 x 1/3 of all light captured.

On that basis alone the mono camera is 6 to 4 faster than the OSC.

If you add an extra hour to each shoot and make the extra hour Luminance (as you would) in the mono then the advantage rises to 9 for the mono against 5 for the OSC.

In mono you can also save time by...

binning colour 2x2.

Shooting the right amount of each colour. OSC captures twice as much green as red or blue which is absurd in astronomy.

And as Sara says you have the moonlit time in which to capture Ha.

 

Your suggestion that OSC is faster is simply not correct.

Olly

PS A while back I posted a 'Speed Heart' image to demo the speed of the mono camera. In this case I used 20 minutes per colour and an hour in Ha (no luminance this time) to produce this two hour image in an F5 system. I do not believe that, at F5 and in two hours, and OSC camera could get anywhere near this result. The processing was also done quickly in keeping with the whole point of the project.

 

[geordie85]

Maybe save yourself some money and just get a light pollution filter like the IDAS lps p1/ 2. You can pick them up 2nd hand for around £100 or new from FLO for abit more.

https://www.firstlightoptics.com/light-pollution-reduction-imaging/idas-d1-light-pollution-suppression-filter.html

[ste7e]

5 hours ago, swag72 said:

Spend some time with the FOV calculator I linked to..... A great starter camera to mono CCD imaging is a Sony 285 chip that is in the Atik 314L+ for example (I'm thinking that these come up second hand now for about £500......) Its a hellishly small chip though when compared to the DSLR but many imagers have cut their teeth with this camera and its a belter. 

There is also the ASI1600 that you can look at - There's a big thread on the forum if you do a search..... look at the images and make up your own mind. It's a new CMOS sensor setup that none of the other main manufacturers (apart from QHY I think) have put it into their line up. The ASI1600 uses a much larger chip than the Sony 285 (almost akin to the DSLR) The larger the chip, the less tolerance a scope has in the corners and then you start needing field flatteners - There's a lot to be said for the ease of a small chip

Hope that helps. 

Thanks, Sara.  I'll take a look at my options with the FOV calculator.  And, I'll take a look at the Atik 314L+ and the ASI1600.

[Mick J]

6 hours ago, ste7e said:

Thanks for this.  I really hadn't realised that nb was only feasible on mono cameras! Feel a bit stupid about that. 

So that means filter wheel and an expensive set of colour filters... i can feel my wallet shrivel at the thought...

Lots of NB being taken on dslr's modded or not, nice expensive 2" NB filters - we went from a modded canon 450d to a secondhand 314L+ and the difference was dramatic, the benefit of cooling............  the other cmos Sara may be thinking of is the QHY163M, thread here   Herra and Luis both competent imagers.  Gina has one or two posts using the ASI - some tucked away in her rig modding 3D printing thread.

 

[gnomus]

Another vote for mono imaging here.  But these things are not cheap.  Do have a look at that FOV calculator Sara recommended, or this one http://astronomy.tools/calculators/field_of_view/

You would need to be happy with the smaller chip.  

I know at least one chap who started off with a manual filter wheel, and these can be had relatively cheaply.  Electric is nice but not essential.

And finally, the used market can be your friend.

[Alien 13]

The thing that scares me off mono is the price of decent size sensor and the filters that can be in excess of £500 each.

Alan

[swag72]

The filters *can* be in excess of £500 each..... but they needn't be.....Cheaper can be purchased

[carastro]

I totally agree with Mono and NB.  I originally used a DSLR and then bought an Atik314 Mono.  The shock of the sensor size made me re-sell it and get a camera with a larger sensor.

BUT

A while later I realised I could have simply got myself a smaller scope and focal reducer, and the FOV would have been less of a shock for large targets.  I re-bought an Atik314 later on and it is now a treasured possession.

Carole 

 

[Gina]

As many on here know, I'm a dedicated mono camera and NB imager.   I started out with a modified DSLR, upgraded to Atik 314L+ mono CCD with it's tiny sensor, then Atik 460EX mono - bigger, and now the ZWO ASO1600MM-Cool with 16Mpx resolution but still usable with 1.25" filters. 

Have to say I'm very impressed with this camera and still experimenting to get the best out of it.  Apart from high resolution and only needing small filters, I can get away without guiding by using short exposures and a lot of them.  Only problem with that is that it creates a lot of data which needs plenty of HD space and takes longer to process.  But large disks are pretty cheap these days.