I bought a new 35mm lens for my Canon 600D....

[geoflewis]

After humming and hawing for years, I finally pulled the trigger on a 35mm lens for my old astro modified Canon 600D. I wanted something portable for 'grab and go' widefield full constellation and MW shots. My 600D has barely been used in the past 5 years since I moved over to mono CCD imaging, in fact I sold the camera a few years ago, then bought it back a year later and still have not been using it. The lens I purchased was 2nd hand off mpb.com, and is the EF F2 35mm IS USM. It arrived in excellent condition as advertised.

I had a couple of hours clear sky last night between 11pm and 1am, so quickly set up my Star Adventurer Pro mount with the camera and lens. I only did a quick and dirty polar alignment, so was pleasantly surprised to see that I could get round stars up to 4 min exposures (I didn't try anything longer). I experimented with the different exposures, F2 through F4 and ISO 800 and 1600. F4 certainly yields better star shapes than F2 and its a bit of a crap shoot between ISO 800 and 1600.

Here are a couple of processed images. Both images are single exposures, Orion 3m at ISO800/F4 and the MW shot 2m at ISO1600/F4. The Orion image is cropped, mostly the remove bad LP gradient and blurred tree tops (remants still showing) towards the horizon.

Not bad for single exposures and definitely something to do rather than hours of long exposures with the CCD as and when (or even if) the skies allow.....

I had a lot fun popping over different regions of the sky and then took a half a doz 2m subs of each of the Taurus and Auriga regions. These were stacked without any calibration, stretched and put together a 2 panel  mosaic in MS ICE...

Bands of cloud started drifting through Taurus and shortly after the entire region was lost to clouds.

I'm going to have to learn how to best process these wide FOV images, but can see me doing a lot more of this, either instead of mono CCD imaging, or at the same time when the gear in my observatory is working on deeper DSOs.

Thanks for looking.

 

Edited February 4, 2021 by geoflewis

[astro mick]

I think for single exposures,they are amazing.I think it all depends on what you want for an image.To take deep clean and critical detail,then yes you would need a cooled ccd or cmos camera.

But in saying that over the years i have had many cooled ccd cameras,mainly small chip,but still very expensive.I have walked away from processing happy but not estatic.But overall satisfied.

You can work with what you,ve got,or you can keep upgrading at massive cost.Also you really have to master the art of processing,because if you dont or cant then the camera cant deliver(well it can but you cant.

If i lived in sunnier skies and more clear nights,then perhaps things would be different.

I think in one of the Astro magazines this month,their was a lovely image,but i think it was a total of 90hrs+.

Anyway,i will give it ago,if not then back to a ccd.

Mick.

[geoflewis]

2 minutes ago, astro mick said:

I think for single exposures,they are amazing.I think it all depends on what you want for an image.To take deep clean and critical detail,then yes you would need a cooled ccd or cmos camera.

But in saying that over the years i have had many cooled ccd cameras,mainly small chip,but still very expensive.I have walked away from processing happy but not estatic.But overall satisfied.

You can work with what you,ve got,or you can keep upgrading at massive cost.Also you really have to master the art of processing,because if you dont or cant then the camera cant deliver(well it can but you cant.

If i lived in sunnier skies and more clear nights,then perhaps things would be different.

I think in one of the Astro magazines this month,their was a lovely image,but i think it was a total of 90hrs+.

Anyway,i will give it ago,if not then back to a ccd.

Mick.

Thanks Mick,

Yes, my QSI mono CCD camera is always going to outperform my DSLR, but for the shere joy of pointing this camera and 35mm lens at the sky and firing off a few fairly short exposures, this is hard to beat. As you point out, processing the data is something else completely and for which I still consider myself as having a fairly limited skillset, but it's still enjoyable. As I get older, I suspect that I'll do less heavy duty DSO imaging, but I'm not quite ready for the bath chair yet (hopefully)......

[FenlandPaul]

That combo shows a lot of potential based on those single frames! As soon as you get stacking, with maybe some foreground interest, in something like Sequator you’ll be away!

Wide field DSLR suits my tastes very well, and has the advantage of being more forgiving on processing precision (in my opinion) - I suspect I’d be a bit hamfisted with good quality cooled camera data!

[geoflewis]

30 minutes ago, FenlandPaul said:

That combo shows a lot of potential based on those single frames! As soon as you get stacking, with maybe some foreground interest, in something like Sequator you’ll be away!

Wide field DSLR suits my tastes very well, and has the advantage of being more forgiving on processing precision (in my opinion) - I suspect I’d be a bit hamfisted with good quality cooled camera data!

Thanks Paul,

I'm not familiar with Seuator, so what does that do please?

[FenlandPaul]

5 minutes ago, geoflewis said:

Thanks Paul,

I'm not familiar with Seuator, so what does that do please?

It’s a free stacking software so it helps with signal-to-noise. But its greatest feature is that you can simply mask the sky (you colour it in with you mouse) and can “freeze” the ground so that you don’t end up with blurred foreground. It has the capacity to load dark and flat frames in it as well. I find it very simple and intuitive.

I use it in almost all of my starscape images, like the one below.

 

[geoflewis]

9 minutes ago, FenlandPaul said:

It’s a free stacking software so it helps with signal-to-noise. But its greatest feature is that you can simply mask the sky (you colour it in with you mouse) and can “freeze” the ground so that you don’t end up with blurred foreground. It has the capacity to load dark and flat frames in it as well. I find it very simple and intuitive.

I use it in almost all of my starscape images, like the one below.

 

Thanks Paul, I've just had a look at their website. I'll definitely check it out, though I generally struggle with all these tools, unless I have someone to show me what to do. Usually I get part of the way in, then something doesn't make sense and I end up flaying around..... 🤔

Lovely pic BTW... 👌

Edited February 4, 2021 by geoflewis

[FenlandPaul]

2 minutes ago, geoflewis said:

Thanks Paul, I've just had a look at their website. I'll definitely check it out, though I generally struggle with all these tools, unless I have someone to show me what to do. Usually I get part of the way in, then something doesn't make sense and I end up flaying around..... 🤔

Lovely pic BTW... 👌

As it happens, there was a good tutorial video posted about it a few days ago. 
 

 

Or I highly recommend this guy, who also explains it well (plus his pictures are absolutely stunning!).

 

[geoflewis]

33 minutes ago, FenlandPaul said:

As it happens, there was a good tutorial video posted about it a few days ago

Thanks Paul, that looks pretty straightforward 🤞

[geoflewis]

@FenlandPaul I've downloaded it and had a play. I need better data, but I managed to stack some images, so definitely progress. I like the option to preseve the foreground, so I'll be able to shoot some of those too now, as previously I've avoided that. I'm using a Star Adventurer to track stars, so the foreground is always blurred, but I'm guessing that I could use a shorter exposure to freeze the ground in the base image, then align just the stars. Will try that out anyway. Thanks again for introducing me to this software

[FenlandPaul]

8 hours ago, geoflewis said:

@FenlandPaul I've downloaded it and had a play. I need better data, but I managed to stack some images, so definitely progress. I like the option to preseve the foreground, so I'll be able to shoot some of those too now, as previously I've avoided that. I'm using a Star Adventurer to track stars, so the foreground is always blurred, but I'm guessing that I could use a shorter exposure to freeze the ground in the base image, then align just the stars. Will try that out anyway. Thanks again for introducing me to this software

Great stuff Geof and you’re welcome.  You’re correct that if you’re using a tracker then the foreground would blur anyway (sorry, I’d missed that) but it’s amazing what you scan do with shorter exposures at high ISO and some stacking to reduce noise.  It’s not tracked-exposure depth and quality, but it’s still remarkable and with the added benefit that you don’t have to lug your SA to that lovely landscape site!!

All the best with it!

[geoflewis]

I took another look at the Orion image which had a very red background, as are all the images off the astro-modified 600D with the IR filter removed. Used Affinity Photo levels to better align the channel peaks with the following result, which I think is an improvement.

What do you all think please?

[david_taurus83]

That lens looks nice and sharp!

[geoflewis]

25 minutes ago, david_taurus83 said:

That lens looks nice and sharp!

Thanks David, yes, so far it's everything I hoped from it.

[geoflewis]

I had another somewhat interupted session shooting Orion with my Canon 600D+35mm lens on the SA mount last night. I still don't have as much data as I'd like as I was dodging clouds and snow flurries yesterday evening - somewhat unsuccessfully....!! I set the camera running last night under a clear sky and came indoors to keep warm. When I went back out 20 mins later everything was covered in snow, so I had to start over. but even then I was only getting 10-15m sessions between clouds and Orion started to set into trees, so I had to give up. Anyway, here is what I've managed to extract from the 35mins or so of data that I did manage to collect. I really need a much longer session to be able to push the stretch harder, but I feel as if I'm gradually getting there......

Orion was getting so low into the horizon LP and tree tops by the time I finished collecting data, that I've had to crop the lower edge pretty heavily, but I can just detect a hint of the Witch Head Nebula above the LP in the lower right corner.

Thanks for looking.

Edited February 11, 2021 by geoflewis
updated the image