Galactic Wanderer

5 hours ago, Carbon Brush said:

Yes the camera is much too far away from the scope.

As a daylight test, point your scope at a distant object.
Get rid of all the 2" & 1.25" stuff.
Wave your camera (with live view) in mid air above the focusser.
When you see a focussed image, you have a measure of how much/little adapter train is permissible.
This will guide you on what components are allowed.

I have used this technique on various scopes (newt, Mak Newt & frac) to get a feel for the size of the problem.
In some cases it has meant rummaging in my bits box for the correct spacers/adapters. Hopefully this is the case for you.
In one case it justified the purchase of a lower profile focusser!

If you find you are only looking for a couple of millimetres, look at the main mirror fixings.
Moving the mirror up the tube a little will push focus out.
Depending on the scope, you have to go a long way to make the light spill over the secondary to any extent.

HTH, David.

 

5 hours ago, woldsman said:

You can get a lower profile T-ring (the one you have adds the standard 11mm to the 44mm distance to sensor on the DSLR to yield 55mm back distance).

eg https://www.rothervalleyoptics.co.uk/baader-ultra-short-t-mount-canon-eos.html?gad_source=1&gclid=EAIaIQobChMI6_DftrWUhQMVHpFQBh2SbgZSEAQYASABEgKtYfD_BwE

You probably have alternatives to the Celestron adapter  (if the 1.25 filter is screwed in here) which is occupying a lot of space.

Finally, if you could share a picture of the scope itself there may be options there to reduce the focus distance as part of the focuser unit may unscrew. 

+1 to daylight testing - always a great place to start.. 

Thanks both, super helpful and definitely confirmed what I originally thought. I don't have that much to play with in terms of mm adjustment, I'm adding a good few cm from where it's usually focused. I'm a bit short on these sorts of adapter bits and pieces haha. I think to Woldsman's point, the Celestron adapter can be knocked off entirely. Something in this sort of vein (I think) slots straight into the 1.25 to 2, removing a good 3-4cm from the train. https://www.ebay.co.uk/itm/313079134159?chn=ps&_ul=GB&_trkparms=ispr%3D1&amdata=enc%3A1gusBRbbUSuyKRR5DawI74A53&norover=1&mkevt=1&mkrid=710-134428-41853-0&mkcid=2&mkscid=101&itemid=313079134159&targetid=1647205088280&device=c&mktype=pla&googleloc=9045888&poi=&campaignid=17206177401&mkgroupid=136851690655&rlsatarget=pla-1647205088280&abcId=9300866&merchantid=137597110&gad_source=1&gclid=CjwKCAjwh4-wBhB3EiwAeJsppHXkI0oCw1jhJVWragnd5W1E7_y0sXrbjXFAChpFbCwc3mnE7BsVExoC_P8QAvD_BwE

On 23/02/2024 at 13:52, ONIKKINEN said:

Just how long is your adapter train, can you grab a picture of the setup with the camera attached?

T-ring to Celestron 1.25 adapter (which UHC filter screws into), then 1.25 back to 2 adapter. 

On 23/02/2024 at 14:07, Kon said:

Unscrew the 1.25 to 2 adapter nosepiece and screw your camera with a T-ring to it. I can achieve focus with my DSLR and 200P this way.

This is how I normally attach but 1.25 UHC filter adds the complication 

HI all, 

Quick query about attaching a 1.25 inch Baader UHC filter to (f5) newtonian - camera does not achieve focus. It looks to be due to the lack of focus travel, particularly being f=5. Ideally do not want to use a barlow, but if this is the only way to get any sort of result then am happy to give it go. 

Currently using a 1.25 to 2 and t 1.25 adapter, greatly increasing the distance between the focuser and the camera. Any way of potentially reducing this? 

Best, 

GW 

Thanks Olly - realised this on posting and will post in a different part of the forum. Will take a look at your suggestions. 

HI all, 

Quick query about attaching a 1.25 inch Baader UHC filter to (f5) newtonian - camera does not achieve focus. It looks to be due to the lack of focus travel, particularly being f=5. Ideally do not want to use a barlow, but if this is the only way to get any sort of result then am happy to give it go. 

Currently using a 1.25 to 2 and t 1.25 adapter, greatly increasing the distance between the focuser and the camera. Any way of potentially reducing this? 

Best, 

GW 

Okay all apparently its the 30 inch Schmidt camera at St andrews University - The James Gregory one.

honestly been rummaging around the internet for this one. are there even any? this odesn't include jodrell bank of course.

seb xx

6 hours ago, Peco4321 said:

Here's my latest attempt at the Whirlpool galaxy last night, it was a bit windy and clouds kept rolling in, but I must have had polar alignment and focus really good as I managed 60sec subs and one at 75 sec, ISO 1600, in total only 6 images as it was late, but really pleased with a bit of care I can get this length sub. Stacked with bias frames, no darks or lights in DSS and processed a bit in GIMP. 

Very good indeed. I imaged M51 for the first time yesterday but I have yet to see the final result!

 Lovely Rosette nebula bob and Nige. lI've been enjoying a 3-night clear spell in South West Cornwall and have just been imaging Orion through my 55mm lens.

Here is the result, but could do with more data.

Here is the image I am trying to process - a horrible unevenly illuminated image.

Thanks,

Seb

Ugh!...

TGVdenoise is annoying me. I have been reading Pixinsights tutorial on it but it really does not seem to bet getting me anywhere. I seem to have the general idea that the edge protection is the most vital, however, I always seem to get blurry, out of focus images when I move either the strength or edge protection drastically high/low. Otherwise, nothing really changes in the image (or does it?!). Thanks.

1 hour ago, Sierra Golf Mike said:

I don't think I would get as big an image with my 30D

A good thing to do is to check your FOV on this -  http://www.skyatnightmagazine.com/field-view-calculator 

I found it useful when choosing a telescope

BTW, I did a quick ABE on this.

21 hours ago, wimvb said:

Since you already have PixInsight, why not use its noise reduction methods. They do wonders with most images, and retain detail.

Here's my noise reduction recipe

http://wimvberlo.blogspot.se/2016/07/noise-reduction-for-dslr-astroimages.html?m=1

If you have Warren Kellers book, he describes his method in detail. I've tried it, and it works just as well.

Hey Wim,

Tried TGVdenoise - and it seemed to work when I zoomed in. Here is the result

1 minute ago, mikey2000 said:

Have you tried a free trial of Astro Tools?  It seems to do a rather good job of pulling details out of nothingness and cleaning up background....

Will have a go. Thanks

Just now, mikey2000 said:

Keen eyed members will have noticed me posting about my struggles with an EQ3Pro mount since Jan this year.   I managed this on the Flame Nebula in Orion and my optimistic composition was unexpectedly rewarded with a view of the Horse Head!!!  It's a crop of the full shot so there is some clear star stretching but I hope my new coma corrector can fix that.

 

I'm just amazed what can be pulled out of that humble 150mm mirror.....  I look up at Alnitak since then and I can see these clouds in my minds eye.  Hubble can do better, but Hubble isn't in my back garden in Leighton Buzzard :-)

Wow, brilliant image. I'm thinking about the horsehead and definitely will have a go! Have a go at toning down Altinak, it slightly overpowers the image but apart from that well done!

Some amazing images. Still wrapping my head round about how good these are. I still find it awe inspiring that we can take such images from our backgarden with relatively modest scopes Some top space telescopes 25 years ago  would have had the same results, if not worse. Imaging in London has been challenging but I've improved with every image I've taken. Here is my latest - Lots of grainy background (still don't know how to get rid of this). 35mins of exposure with no flats, no bias, no darks with a CLS filter.  stacked in DSS and processed in Pixinsight.

Thanks, Seb

M42 in black & white. I had pulled out the luminance in pixinsight and was interested with what came through. I still much prefer the color version though

19 minutes ago, Stub Mandrel said:

Also can you post a link to the unmodified DSS stack?

Sorry here, I have compressed one but the other is completely unmodified

Alacant, yes I will have another go, thanks

Pleiades M45.TIF

Just now, Stub Mandrel said:

The dynamic range of that image is TINY, what are using to stack?

Also can you post a link to the unmodified DSS stack?

I think you may either have far too much background light pollution or moonlight or something is not happening right.

Look how much bigger my stars are than yours - the 150P-DS ought to be bringing in far more light at 80 seconds with such a high ISO.

This is 21 60-second exposures at ISO1600, chosen as it doesn't show a lot of gas:

Living in London really limits me and this is probably the reason - I need to try imaging somewhere else in the Uk!

22 minutes ago, alacant said:

Hi. I had the same. Third time lucky, having started an optimistic 30s then 60s, I finally got dust with a 6" f5 at two minutes. HTH.

Nice image! Did you just use the Bresser scope  with the camera? Thanks

Hey guys,

I have come back to M45, this time without the CLS filter and with RAW files but still no nebula! Even after stacking I cannot find a single trace of dust and gas. This time I used 80 second subs instead of 60 second to get a slightly higher exposure length. I am very confused -  

Any help would be much appreciated - Thanks Seb

 Here is the final image - 

This was a very low ISO (100) - I took this a good month ago and then I always used Iso 100 (didn't know a whole lot about imaging then 

Living in London means that you cannot go higher than ISO 1250 - the sky will be washed out.

The subs which I took with CLS filter were ISO 1250 and 80 second exposures.

All of this were taken with a Canon EOS 60d.

Thanks again, this thread has been very helpful in terms of imaging.

seb

19 hours ago, happy-kat said:

Is it really one single exposure of an hour?

Sorry for the misunderstanding - it was about 50 80 second expoures

21 hours ago, wimvb said:

In this case it's not the total exposure time (integration time or time on target) that is important, but the single sub exposure time.

If you want to catch weak detail, you need to let the system collect photons. Weaker target = less photons per time unit. The total integration time can only help to decrease noise (to a certain limit), it will never increase the signal. Assuming that you use a DSLR, with a target like this you would use a low ISO setting which gives you more dynamic range, combined with longer subexposures. Subexposure time is limited by either light pollution or the stars becoming over exposed. To get the noise down, you need lots of subs.

In processing, you need a tool to remove the light pollution. My favourite is PixInsight DBE, but Photoshop GradientXterminator probably works as well.

Good luck,

Wim, that is really helpful. I was very puzzled when the Orion nebula came out with an hour of 30 second subs and was not even close to the 30 mins of 80 second exposures.

20 hours ago, Nigel G said:

Unmodified camera, I would suggest trying without the filter, with m45 I got a much better result without my CLS CCD filter in.

Try a single sub and see if there's a difference.

Nige.

Here is a single sub with out the CLS filter. I will try in RAW next time though.

Thanks, seb

Hey guys, 

I was wondering if you could help me with some shots I took of The Pleiades a  couple of nights ago . This was the final shot - but I don't seem to be getting any dust around the stars even with a stretch. This is an hour exposure with an astronomik CLS filter on a EQ3 with an 150PDS. 

Thanks, Seb 

M27 with 150PDS one of my favourites