Ratlet

2 hours ago, Elp said:

Star processing is (mostly) straightforward unless if you're dealing with the likes of Alnitak type stars , I refuse to use PI when manual processing can achieve similar or close, I'm starting to migrate to GIMP too as it can process in 32 bit (unlike my old PS).

I usually do all processing as is with the stars in, then address them at the end.

I'm quite impressed with PI.  It does its job very well.  I'm just not sure if it does £300 worth of well for my level.

I very much feel that I don't understand what it is doing it's just doing it for me, which isn't really what I set out to do.  I want to understand what's going on and when/why to do certain things.  It does give me a good idea of what I can achieve though, even though I my processing isn't great.  

50 minutes ago, Elp said:

A great result. You've also got rid of the red/green star halos which is the main issue with these lenses. Considering how old these lenses are they're quite fantastic.

I think that with the usb3.0 connection improving transfer speeds it made getting a good focus a lot easier.  I suspect it might also help that the 533 sensor is quite small.  However paired with a 200mm focal length it is a very nice size for framing a wide variety of objects.

There is a slight light blue halo around some of the stars, but it is so close to white that I think it sorted itself out in pixinsight.

I'm going to have to learn how to do this in Photoshop though.  I've been riding the free trial and it can't have long to go and I'm not quite ready to drop the bank for the full version.

To quote Important Joe "Do not, my friends, become addicted to Pixinsight. It will take hold of you, and you will resent its absence!"

The lens is fantastic.  I did consider getting an evoguide 50, but I don't think it's services will be required.

I would highly recommend them to other people just starting out as they can provide easily manageable images and can save you a LOT of money Vs an alternative (redcat, evoguide) allowing you to put more money towards a mount.

jpg of the stacked image prior to editing.

I probably should have checked the CCD suitability calculator before buying it, but my Hypercam 533c is massively undersampled for the focal length I want to use it at: 200mm Takumar SMC.  Still, nothing ventured, nothing gained.  So with a camera that is going to massively undersample, a lens which was made in the early 1970's and a darn near full moon I decided to find out just how badly I messed up.

Turns out, not that much.  Lens was stopped down to F5.6 using a step down ring because I'm not a huge fan of the diffraction pattern).  With 2 hours of 90s captures (hand picked because I had darks for 90s) the image came out pretty clean (I'll post it below).   Edited in Pixinsight for colour calibration, EZ Denoise, EZ Soft Stretch, star reduction, star removal for drawing out some more nebulosity then mashed it back together.

So.  I finally got the SMC Takumar 200mm out for a proper session.  Below is 2 hours of stacked 90s subs, stepped down to F5.6.  I used an Altair Astro 533c Hypercam for this and the shots were guided.

These were taken with the moon about 90-95% full.

Stack is photometric colour calibrated and auto-stretched in siril.

I think it turned out pretty well.  The stars are (to my eyes) very tight with a slight hint of blue fringing.  Focusing was manual (no mask) as per @alacant recommendations.

For a £40 lens I'm absolutely delighted.

I'm resisting buying expensive eyepieces because I believe the biggest issues I have is PBEAG (Problem Between Eyepiece and Ground).

Every time I looks through my eyepieces at a target I've viewed before I think I see more detail.  I get the feeling that looking is a skill and my skill level isn't up to getting the most from an expensive eyepiece or a massive wide field of view.

Going to the car analogy, im still learning to drive and I can do that in my Vauxhall Nova. 

bits continue to beget bits...

Starwave side by side mount arrived today.  This should help minimise issues with trying to mount a guide camera to my various lens setups.  Also got a 12V male to male cable so I can power the camera off the GEM28 mount and reduce the number of sockets/cables.  After lunch I'm going to print up an enclosure to hold my NUC on the middle and that should help tidy everything up a fair bit!

For a 4 hour session you can probably get away with dew shields rather than dew heaters.  That's how long I image for usually and with shields I've not had any issues even with fairly high humidity.  Go DIY with some craft foam.  You absolutely will need a few shield/heater for the guide scope.  Remember you can make the shield surprisingly long on the scopes.

Do you have the canon Eos utility software installed on the computer?  Can't remember the exact name of it but it's the one that lets you remotely control the camera settings.

It plays absolute hob with other software seeing the camera.  First thing is to make sure that it doesn't launch when a canon device is plugged in and then remove it from the startup programs so it's only launched when you want to.

Night not be the issue, but in my experience, if it gets a whiff of a canon camera being plugged in it prevents other stuff from seeing it (such as Nina).

I think you can get an effect similar to astigmatism if the sensor is too close.  You might get away with just increasing the distance from how you describe it.

From memory the actual distance required is more of a guideline.

4 hours ago, powerlord said:

appologies if 3 posts appear, but I've posted twice from my mobile and they've not appeared.. anyhoo - setup for tonight.

As you can see the big guns are out for a clear night of DSOs. what ? that AM5 is as big as a family car.. don't let those pics on ZWO site decieve you!

targets:

sii ic1396 with the redcat and asi1600 (yeh yeh...just guide scope fitted at the mo in a bid to get a better PA as I've been struggling to get it precise since I got the AM5..I suspect my other OTAs I've been mounting are not square, but really its a mystery other than the fact you need to be pretty precise with the AM5 or it can't guide well).

ic417 and ic405 with the canon 300mm - and this has L-ultimate fitted.. so we'll see how it gets on with F4.

And yes - that is my observatory made out of correx - still going strong, still water tight and ship shape and in it's 10th month of life!

stu

I did thinking that svbony was a little overmounted.

I'll add that I'm currently using the 130pds for visual, however if/when I star using it routinely for imaging I'll be getting a dob.

Personally I would avoid a Newtonian on a eq mount.  I've got a small 130pds on an AZ5 which is fine.  Eyepiece always in a great place, travelling through a nice arc. 

Tried it on my GEM28 once.  Only once. It felt like every time I needed to change target I was rotating the tube or it was at some weird position.

If you are going down the Newtonian route for visual I'd suggest a dob or alt az mount.

1 hour ago, Skyline said:

A smelting new Quattro 150P with the included bespoke coma corrector.

I bought my 130pds just before this got released.  If I'd known it was coming I would have waited!  It's a phenomenally good price for the kit when you consider it comes with the coma corrector.

Not a major improvement and probably quite situational, but I 3D printed a small adapter so I can mount my guide camera in a Vixen dovetail mount.  I'm picking up a side-by-side mount so this should make it easier to get everything I need on and not have to spend more money on more bits.  It's friction fit so very snug but fits on my SVBONY 30mm guide cam, RDF and my skywatcher finder scope.  Once the mount is tightened up it is very secure.

finder to vixen rev 1.stl

Bits beget bits...

The Gods of Astronomy clearly approved of my Hypercam purchase and showed their approval by having this canon Eos filter drawer adaptor show up on the forum for a great price.  Now I can use my vintage glass easily.

Further approval was yesterday when I found a side by side mount so I can get a bit cleaner setup for the mount (once it arrives)

Having played with my new camera on my 130pds (650mm/f5) I've been looking at imaging opportunities with my 200mm (takumar 200) and 300mm telephotos.

I was wondering though, is there a point where I get better data doing a mosaic with the 130pds with its larger aperture Vs trying to capture the image in one go with a smaller aperture?  My 200mm would be stopped down to f5.6.

Would I get more/better data doing a 9 panel mosaic with the 130pds 1 hour per panel Vs doing 9 hours of a single panel with the takumar? I feel there should be a simple answer but I can't wrap my head around it.

A small update for everyone:

I got The Deep Sky Atlas and Turn Left at Orion.  Both of these books are fantastic and are great for planning an evening and for just figuring out what is up there.  However, once I've decided on what to look for I go full on Mr Spock and print narrower FOV views of the object I'm trying to find.

This coupled with the 32mm Plossl in my 130pds makes it very intuitive to find things.  Dare I say the finding is almost more fun the actual observation. 

I've primarily been using the 130pds for visual being treated as a pocket dob of sorts, however, I bit the bullet and bought a dedicated astro cam (Hyperstar 533C) and the only thing I could fit it to was the 130pds.

There was a lot of troubleshooting but I managed to get some decent data.  Each image is 25 minutes of 90s exposures, stacked in siril and stretched using asinh and normal stretching 

Woefully underprepared would be the best way to describe my evening.  But the much vaunted clouds climaxed too quickly (I feel ya bud) and the storms earlier in the day blew away by darkness.

Really want to give the new Hypercam 533 a shot since the weather looks garbage all week.  Early results look very promising (once I figured out the focusing).

Wee bitty more zoomed in than I was used to with the canon and 300mm tair!

Did a sharp cap sensor analysis.  Turns out most of my lcd screens have flicker which isn't ideal so had to point it at the ceiling with a bit of paper over the sensor to get a good run

Ordered a packet of Haribo and got a rather fetching free hat.  Must say I was surprised by the Peli case.  Seems a bit OTT.

Also came with a Hypercam 533c which probably explains the cost of the Haribo.  I just put it down to inflation.

7 minutes ago, Elp said:

Think I tried it, but at the time left the Takumar on the DSLR and a Samyang on the astro cam. What size rings are you after, you have a couple of options:

1. Get the adjustable 3 screw double ring type which typically comes with finder/guide scopes, this is a bit of a fiddly way of doing it but provides you scope for accomodating a variety of diameters. Can hold the lens or the camera.

2. Get rings to clamp onto the OD of the camera. I've got two different diameter ones, one of which I repurposed from my WO scope, in order to use that one with one specific camera I ordered some o rings to fit around the eos lens adaptor thus increasing its diameter and it now clamps tight.

3. I assume it's an m42 takumar. If you were to utilise Eos lens adaptors you could get the filter drawers or lens adaptors and clamp around them. This has the added benefit of keeping any filters enclosed and away from stray light hitting it at angles if they were mounted on the front of the lens.

I've been using one of the adjustable 3 screw ones with my DSLR, mostly just to keep it lined up correctly.  I'd discounted that for the dedicated camera as I had visions of the whole lot sliding out and landing on the floor, but then I guess you use those rings to mount a guide scope so there isn't much of a difference.

I do have an Eos extension with filter drawer on its way.  I'll see what other opportunities that presents for mounting when it turns up.

20 minutes ago, Elp said:

Think abs or nylon are the best mechanically. If an astro cam is attached ask yourself would you trust a 3d print to secure this (I know many do). Personally I don't so I stick to metal rings.

Do you use a dedicated astro cam to image with the takumar?  Part of the reason I'm looking at this is because I'm struggling to find proper rings.

I'm due to be taking delivery of one of these tomorrow.  There seems to be very little information out there on the unit so I was wondering if there is any tests I could run on it that would provide useful information for the community at large.  Would it largely just be sharpcap sensor analysis?

I'm pretty sure with temperature control I should be able to build some dark masters too not sure what other masters I can make, although that would obviously be only for the camera.

There is supposed to be some clear skies over the weekend so I'll be giving it a burl.  Not got the adaptor for my canon lenses but will be trying it on the 130pds without coma corrector which should hopefully provide some interesting information (and seagul stars)