Knight of Clear Skies

3 minutes ago, alacant said:

Anyway, we can but try. You do the heq5 and I'll do the ed80!

I like to champion cheap m42 camera lenses from the 60s and 70s. I've yet to find one I can't get a decent image out of.

1 hour ago, emyliano2000 said:

I did replace the silly aluminium tripod with a stainless steel one for increased stability and upgraded to a losmandy saddle though. 

Yes, some people have suggested it's actually the tripod that's the weakest link. We also don't know what the quality control's like, perhaps some are more precisely machined than others?

Very nice, and I like the framing.

Yes, we're both on the same page.

2 minutes ago, MylesGibson said:

It's annoying to constantly hear people tell me I need a HEQ5 as a bare minimum to get anything worthwhile.

Yes. It's difficult to recommend the cheaper mounts for telescope imaging as it can be a recipe for frustration and imaging opportunities in the UK are limited. But if you already have an EQ3, are on a tight budget or have the time to sort out any problems then they can be rewarding.

Here's a slightly toned version I made after checking on another device, not sure about my monitor calibration now I've moved my desk.

I also found an object of interest in frame. A microquaser has been ejected from the vicinity of the Heart nebula by a supernova kick.

Good to see Sara, AP isn't just about the showpiece objects. Hope you are doing OK down in Spain.

This might be a good place to ask, is there an easy way of checking images for minor planets within the field of view? I must have captured all kinds of things over the years without realising it.

5 minutes ago, verreli said:

Still a week to go before SWAN is visible from the UK but the light curve is doing strange things.  From a peak of Mag4.7 it's now down to Mag5.7.  That's a 2.5x decrease in brightness despite getting closer to the sun and earth.  Is it going to fizzle out?...  Comet chasing is a frustrating sport.

A shame, but thanks for letting us know.

Just a thought, but does anyone have or can find any Milky Way shots taken with a smartphone and Barn Door tracker? Would be interesting to see what could be done with this real budget combo. I've tried searching but have drawn a blank.

5 hours ago, happy-kat said:

Does my manual barn door that reliably does 180 second exposures at 40mm focal length count? No tripod needed as self contained and made from bits, most expensive item after the camera was the ball head at £15 or so. 

Just a thought, but have you ever tried putting a mobile phone an your barn door tracker? Would be very interested to see what this combination could do in the Autumn, with the Milky Way high overhead.

Good stuff, applaud the idea and invention. I've been thinking on similar lines, about how far a real budget setup can be pushed as one of my Autumn projects. Could be a fun thing to do while I have my 1600MM cool shooting away on a scope again. This qualifies as a budget image, an RGBHa collaboration between two 135mm lenses on an old modded DSLR.

But it's not quite as budget as I'd like as I used my £300 Samyang 135mm f2 to shoot the Ha rather than the £18 60s era Takumar 135mm f3.5. I could have got a similar result with the old lens with a bit more integration time.

The advantage of a simple rig like this is that it absolutely works every time and is forgiving to use, sloppy polar alignment doesn't matter much and it's easy to find targets with such a wide field of view. This is ideal for UK skies where imaging time is limited. I didn't have to use any DIY skills to put it together (had the camera modded for me) and it doesn't require a laptop. Something like this could realistically be put together for under £600, including the Ha clip-in filter.

AP doesn't have to be an expensive hobby (in monetary terms anyway, it's definitely a time sink). Pretty much anyone who really gets into AP is going to want to move to a smaller pixel scale, in the image above shock fronts are starting to show but it needs more detail to do these objects justice. But I think budget setups have plenty of untapped potential, something like a Cygnus mosaic wouldn't be that difficult to put together.

Then someone else can make a video about how I'm off my rocker for spending £600, showing me what can be done with a mobile phone and department store scope.

Good effort, it's really not easy to do this but it can produce surprisingly good images. I can see a bit of blur so I'd guess the camera wasn't quite still enough. A phone holder for the telescope would make the most difference, as you could then take a number of frames and stack them. Stacking a video might also be an option, depending on what resolution it takes video in.

Sorry, my reply was confusing. DSLRs typically have two IR filters in them and only one is removed for better Ha response. For full spectrum cameras both filters are removed. It's only full spectrum cameras that suffer from UV/IR star bloat, most lenses aren't designed to focus UV and IR light on the same point.

This link explains in a bit more detail, for Canon cameras the LP1 (UV/IR) remains in place.

4 minutes ago, smr said:

Ok thanks very much for your reply. I was under the impression that the UV/IR filter was needed no matter the type of mod, but as I understand it the full spectrum mod is only necessary if you want to take IR photographs in the day time? If so then I wouldn't need that mod, just the filter removing is all as I'd be using the camera solely for deep sky imaging. 

Yes, that's right. Confusion over this is very common.

A few thoughts.

1 hour ago, smr said:

The colour balance - how easy is processing regarding this as I often see comments about modification affecting the colour balance of images. 

Star colours - I've read about modified cameras being affected by not being able to produce natural star colours.

Sometimes it's a pain, sometimes not. I use DSS to stack and I find it's initial colour balance and levels to be very random at times. Probably has more to do with DSS than whether the camera is modded or not.

1 hour ago, smr said:

Regarding ISO, I use my 80D at ISO 200 and because I use ISO 200 I can get 5 and 10 minute subs without overexposing or washing the image out, in a 10 minute sub the peak would be 50 percent on the histogram.. I think with the 600D I would need to use a higher ISO, which I think is probably ISO 800, so I'd need to use a light pollution filter if I wanted to do 5 minute subs?

I believe ISO 200 is too low for this camera and you'd get better results with shorter subs at a higher ISO. ISO 200 is below unity gain which results in the camera discarding real photons.

1 hour ago, smr said:

Regarding calibration frames and darks; I don't take darks with my 80D, I just use dithering and BIAS along with my Lights. Can I do the same with an astro modded camera?

Yes, no difference. I don't take darks with my DSLR either.

1 hour ago, smr said:

Star bloat - I think I'd need a UV/IR filter with a modified DSLR? What if I wanted to use say a Ha Filter, does this effectively replace the UV/IR filter? Likewise if I wanted to use a filter like the IDAS D2, would that replace the UV/IR filter ?

A UV/IR filter is only required if the camera is 'full spectrum' modified.

1 hour ago, smr said:

Before going ahead with this though, I'd need to factor in any other costs which I may need... If I want to shoot Ha when the Moon is out I'd need an Ha filter for instance.

I'd recommend a clip in Ha filter anyway, even from a truly dark site it greatly helps to isolate nebulosity from the background. But this does require the right software to align the images, which is another cost. I've just bought Registar to do this.

Hope that's some help.

Well done, you have the makings of a good image here. I'd recommend a bit of curve adjustment to bring the background down.

Hope you enjoy the lens, you can do a great deal at 50mm focal length. A tracking mount will make a big difference. Interesting that you're shooting at f2.8 and using lens correction to reduce the coma, might give that a go with my 50mm lens. Most people stop 50mm lenses down to about f4 but it gathers twice the light at f2.8.

Nice subtle image that hasn't been pushed too far for the data, I like it.

Sorry mods, meant to put this in the Widefield Imaging section. Would you mind moving it for me please?

Nice capture, I always like to see objects of interest as well as the most photogenic objects. I had a feeble go at capturing it a while ago with a 200mm lens, thinking at the short focal length I might get a slightly nebulous appearance, but all I got was a small and faint star cluster. There is also a Quasar at 8 billion ly distance around there, not sure if it's in your field of view.

If you're interested I put a few links about the Draco Dwarf and its discovery in this thread, including the original discovery plate. You've captured the RR Lyrae variable stars that were used to identify it as a separate galaxy.

Very fine first first image. Possibly the background is a little too dark.

Here's another effort with the Samyang f2 and 1100D, with clip-in filter.

And here's the result of blending this into an RGB image I previously took with a 135mm Takumar f3.5 lens (more details here.)

Splashed out on Registar today and had a go at combining a recent Ha image with an RGB one from 2014. Here's the Heart & Soul nebulae along with the Double Cluster.

This was a collaboration between two 135mm camera lenses. The RGB image was shot with an old Takumar 135mm f3.5 lens (wide open). The Ha data was taken with my Samyang f2 lens (at f2, using a clip-in filter). Camera used were a modded 100D for the RGB image and my 1100D for the Ha. The RGB image was 38 minutes and the Ha was 50 minutes (2 minute subs in both cases).

This image has been gestating for a while, looking at the serial number on the Takumar lens it was manufactured in about 1965. It cost me £18.50 on eBay. Think I may have stumbled on a really nice combination for RGBHa imaging, I will think about a dual rig for the Autumn.

Field of view is 9.26 x 6.13 deg, here's its location straddling Cassiopeia and Perseus.

And here's the plate-solved version. I like this composition as it shows two stages of a star's life-cycle, formation and early life in a cluster.

This is the Ha image I blended into the red channel.

Really pleased with this, would welcome any feedback. Ended up making the starfield very sparse with a Tighten 1 pixel action in StarTools, as it showed the nebulosity off better (for comparison, a 2016 reprocess of the RGB image is here). Still could use a little work, NGC 869 and some bright doubles have blobbed up a bit in processing but I need to work out how to blend in a less stretched version selectively. If anyone has any tips or could point me towards a simple PS tutorial I'd be grateful.

Very nice indeed, lots of room for the balrog to roam in.

Thanks for the thought @Allinthehead. Might be worth posting in the 'Getting Started with imaging' section too, as clean data is much easier to process.