Imaging with the 130pds

[alexbb]

Meanwhile, I had some spare time today and I processed some partial data for M27. 8h of O3 and 4:40h of Ha. Need more data. Perhaps ~16h of O3, 10h of Ha and some RGB.

[Galen Gilmore]

5 hours ago, moise212 said:

Meanwhile, I had some spare time today and I processed some partial data for M27. 8h of O3 and 4:40h of Ha. Need more data. Perhaps ~16h of O3, 10h of Ha and some RGB.

Nice color!

[Atreta]

Could someone please post a picture of the secondary viewed from a collimation cap? I ask because I'm trying to align the secondary mirror to the primary mirror  but can only make it to show two of the three primary clips..

Thanks. 

[alacant]

 

1 hour ago, Atreta said:

secondary viewed from a collimation cap

Here's mine. AFAIK -in Europe at least- a collimation cap is an old film canister with a hole in the centre. Maybe that's not it? Some confusing terms!

This snap is with the secondary positioned ready for the primary to be tweaked with a star test.

Post a picture of yours and we'll be able to help better.

HTH

Edited May 10, 2018 by alacant

[JohnSadlerAstro]

Collimation is something ive never been very good at--ever since i took all the mirrors out to put flocking in, I don't seem to be able to get the mirrors lined up properly. Right now, both a laser and the Cheshire say its collimated properly, but the primary is obviously tilted towards the eyepiece side of the tube.

Does that mean i need to tighten the screw on the opposite side of the secondary to the focuser, so that I can then relax the primary mirror again? It's all rather confusing, and never seems to work out the way all the tutorials ive read/watched say it should. 

John

[al-alami]

Starting on a new target last night ... M5 .... I only got time to capture the luminance channel then it started to rain ..... and the forecast is calling for three days of heavy dust!!!!! I'm quite sure I didn't buy any new equipment!!!!!

This is about 90 X 64s exposures.

[spillage]

8 hours ago, JohnSadlerAstro said:

Collimation is something ive never been very good at

Have you made sure that the focuser is aligned (if this was removed).

Mark.

[JohnSadlerAstro]

Just now, spillage said:

Have you made sure that the focuser is aligned (if this was removed).

Hi,

I didn't remove it for the flocking process, although I did make sure that was level all the way round with its mounting. I guess part of the trouble is that I never did much collimation until i got my PDS and the image coma became an issue. With some more practice, I'm sure it will improve.  

John

[Susaron]

4 hours ago, al-alami said:

Starting on a new target last night ... M5 .... I only got time to capture the luminance channel then it started to rain ..... and the forecast is calling for three days of heavy dust!!!!! I'm quite sure I didn't buy any new equipment!!!!!

This is about 90 X 64s exposures.

Following me jajajaja

[Atreta]

15 hours ago, alacant said:

Post a picture of yours and we'll be able to help better.

Thanks a lot, Alacant. 

This is how it looks like through the cap and with the focuser racked all the way out :

This one is from the secondary without anything on the focuser just to show its position related to the draw tube:

I noticed that if i rack in the focuser and look through the cap, the position of the reflection shifts., it moves over to the left. 

[alacant]

7 hours ago, Atreta said:

This is how it looks like through the cap

OK. Can you post a shot of the cap? Is it a sight tube with cross-hairs? A Cheshire with cross-hairs maybe? IMHO best to forget that ATM and concentrate on the second shot you posted. Make a simple cap (see my shot here) so that your eye or phone are centred in the focuser tube. From the orientation you have ATM the secondary needs moving up the tube -away from the primary- and vertically -up relative to the orientation you have taken the photo-. Make it concentric. That will get you close enough for a star test or your other cap. Whatever your cap is is, I don't think you'll be able to see all three mirror clips using it as it has too small a diameter.

HTH and good luck.

Edited May 11, 2018 by alacant

[alacant]

7 hours ago, Atreta said:

if i rack in the focuser and look through the cap, the position of the reflection shifts

Mine does that too. So also does a new one I bought for another project. They also slip unpredictably and change focus when you use the lock screw. Hopeless. YMMV but I've had no luck with sw focusers. Ever. Leave it locked in the focus position and collimate from there is your best bet. HTH.

[JohnSadlerAstro]

3 hours ago, alacant said:

Mine does that too. So also does a new one I bought for another project. They also slip unpredictably and change focus when you use the lock screw. Hopeless. YMMV but I've had no luck with sw focusers. Ever. Leave it locked in the focus position and collimate from there is your best bet. HTH.

Yes I have noticed this issue as well. Unfortunately the default focusers just don't keep steady at different focus points. (Although, once they are locked in position its all good, so not realy much point in getting a new focuser unless you plan to image with 2 entirely different cameras in one night. )

John

[Susaron]

1 hour ago, JohnSadlerAstro said:

Yes I have noticed this issue as well. Unfortunately the default focusers just don't keep steady at different focus points. (Although, once they are locked in position its all good, so not realy much point in getting a new focuser unless you plan to image with 2 entirely different cameras in one night.

John

You can change the focuser to a Moonlite :-)

[Atreta]

15 hours ago, alacant said:

OK. Can you post a shot of the cap? Is it a sight tube with cross-hairs? A Cheshire with cross-hairs maybe? IMHO best to forget that ATM and concentrate on the second shot you posted. Make a simple cap (see my shot here) so that your eye or phone are centred in the focuser tube. From the orientation you have ATM the secondary needs moving up the tube -away from the primary- and vertically -up relative to the orientation you have taken the photo-. Make it concentric. That will get you close enough for a star test or your other cap. Whatever your cap is is, I don't think you'll be able to see all three mirror clips using it as it has too small a diameter.

HTH and good luck.

Thanks again, i used the upper part of the Cheshire.   I'll make those adjustments you mentioned and try again.  

Here's a picture of what i used, i guess the hole is too small compared to your picture. 

 

[alacant]

47 minutes ago, Atreta said:

 I'll make those adjustments

Your cap is fine. Better than mine. Does your Cheshire have cross hairs?

[Atreta]

Yes, it does. 

[alexbb]

One more and perhaps the last solely with the 130PDS. I will add more data to this, but taken through another scope.

This is 8h Oiii and 7h Ha.

[RolandKol]

At last I managed to catch the Eagle!
(fell a sleep and spoiled 50% of images... lesson learned... beer+AP=no no!)
I am not yet good at processing, any advice will help!  it looks bit too red for me.

Thanks for watching!

[Eagle Nebula [M16]. SW 130PDS, Canon 1300D +LP filer, [30x120s, ISO800] - Woolwich]

 

[rotatux]

A very nice one. I think it *is* very red actually (and confirmed by my first try at it last year).

But your stars are all white or reddish so it might be too red and need a bit of color rebalancing. Depending on the software you use, it may have the option to auto-calibrate colors based on known star colors (use it with high-depth image so ≥ 16-bit). Otherwise have a play with manual white balance, maybe after subtracting a bit of red channel.

[alacant]

53 minutes ago, RolandKol said:

bit too red for me

Hi. Not sure. I tried balancing it a bit but lost a lot of the nebula:( Great shot anyway:) Maybe do longer light frames? HTH and clear skies.

[Stub Mandrel]

2 hours ago, RolandKol said:

At last I managed to catch the Eagle!
(fell a sleep and spoiled 50% of images... lesson learned... beer+AP=no no!)
I am not yet good at processing, any advice will help!  it looks bit too red for me.

Thanks for watching!

Well done!

It's a challenge here, but I should be able to get an hour and a half on it if I time things right.

 I could set up on the kitchen's flat roof and get a better view, but I think the neighbours might object to me being level with their landing window...

[RolandKol]

2 hours ago, alacant said:

Hi. Not sure. I tried balancing it a bit but lost a lot of the nebula:( Great shot anyway:) Maybe do longer light frames? HTH and clear skies.

 

 

Thanks, this what actually happened to me also... So I decided to leave the reddish one  
 

Yep, I hope I will manage to add a bit more images to the stack, and unfortunately, 120sec is the top I can go for as LP does not allow to go for longer ones... 

Even at 120sec Histogram is very close to the right... LP filter does not help, + Moon!

P.S.

Thanks guys for advices, I think I will try to subtract background 2 or even 3 times and see what happens with color calibration after.

Edited June 3, 2018 by RolandKol

[Stub Mandrel]

1 hour ago, RolandKol said:

Thanks, this what actually happened to me also... So I decided to leave the reddish one  
 

Yep, I hope I will manage to add a bit more images to the stack, and unfortunately, 120sec is the top I can go for as LP does not allow to go for longer ones... 

Even at 120sec Histogram is very close to the right... LP filter does not help, + Moon!

P.S.

Thanks guys for advices, I think I will try to subtract background 2 or even 3 times and see what happens with color calibration after.

Split into two layers, use the reddish one as luminance and change the colour balance of the other one.

[Atreta]

My last one, m8-lagoon nebula. 

Only 58 minutes worth of integration. 

 

Ps: i named it wrong when saving