Andromider

[jonnyboy]

anyone tell me where i went wrong with this, no matter what exposure i did i could not get detail. i am out again tonight to try again so any help will be great

[CELESCOPE]

Hi There, need a bit info on that one , what camera , what scope , what exposure. any filters etc, might be able to help then J.B

Rog

[jonnyboy]

ihave taken about 35 images and they all look the same. skywatcher 100ed, sxv h9. lp filter focal reducer 0.5. i tried different exposures at 2x2 bin. this one was 35 seconds. i used the starlight software. thanks for your reply rog

jb

[CELESCOPE]

OK JB first of all .dont bother with the moon up . u wont get much detail now wait for it to go , binning 2x2 is fine . exposure time at 2x2 45 secs is ample for each exposure.a CLS filter helps for light polluted areas, the main thing is with M31 the core can easily be burnt out,this can be soretd if u have Maxim software , other wise take very short exposures for the core , for getting the detail in the outer lanes around 50 to 60 subs are needed, then once you have processed both the short frames and the longer frames into 2 images , you can then merge the two into one using Photoshop , i do mine in layers , hope that helps.

just one more thing imaging nebula in the full moon can be done using an HA filter , but galaxies are not so good in moon light so best left alone mate .

Rog

[Kaptain Klevtsov]

First obvious thing is that the centre bit is a white blob because the core bit is overexposed. You need to reduce the exposure time for this bit or you lose all the detail. Next bit is either gain or gamma setting. These modify the contrast of the image and you need to turn down the contrast so that the faint dust lanes show up without the centre going dodgy.

In Registax, open the Gamma window (click the tab at the right hand side during the wavelet adjustment) and move the red dot in the centre of the line to the left a bit. You can move it about and add extra dots. Regularly click on the "do all" button to see whats happening to the whole image.

In Photoshop open the curves window (Ctrl+M) and adjust the curve in the same way as Registax. You can make the sky blacker by moving the bottom of the line to the right, start off with a steep curve to bring out the faint stuff and then flatten out the right hand side of the curve to dampen the core out.

HTH

Captain Chaos

[jonnyboy]

you mean i could still salvage these?

cheers jb

[Andrew*]

Personally I would be absolutely overjoyed with that pic. I couldn't even see that through my scope, let alone image it! All I got was a fuzzy oval.

AstroPhethean

[jonnyboy]

cheers for that. don't get me wrong its my 1st image worth keeping and was pleased big time but hopefully when the moon has gone i should improve it with the help i am getting.

jb

[Kaptain Klevtsov]

you mean i could still salvage these?

cheers jb

Quite possibly, whizz 'em over in e-mail if you like, and I'll have a bash. Can't promise anything, but I can tell you more once I have the raw data.

Captain Chaos

[Kaptain Klevtsov]

Had a play with some files that JB e-mailed me. The TIFF files came out like this

As there were only 14 frames the dust lanes didn't come out well. More frames needed on this and it would be a cracker.

The JPG files that he sent me were very overexposed (here's one)

The only problems that I can see with these images is a lack of frames and the wrong exposure. Tracking and focus were spot on.

Vignetting was evident on the TIFs as well but that is fairly easily cured in Photoshop.

Keep at it JB, you have the makings of some exceptional images here, another 30 or 40 of the TIFFs and it would be outstanding.

Captain Chaos

[jonnyboy]

well it is defiantly improved thanks for having ago for me. i have been working on the focus and tracking as i was told its the most important bit and like you said i shall take more images next time.

i am very pleased with the outcome of this and shall be bending the truth a little and say its what i did, if thats OK with you.

thanks again.

jb

[CELESCOPE]

aGreed had alook myself at these , the dust lanes are there , and the core is ok in the tiff, this points to , a no no when the moon is up , and at least 40 to 50 frames , when the moon has gone , then you should have a very nice image , try not to over process the image as this only spoils the core , better luck next time

Rog

[Kaptain Klevtsov]

Well JB, you took the frames so its your image. If you use film, you don't give any credit to the processing lab do you?

Captain Chaos

[jonnyboy]

very true jon. had ago myself worth a laugh. when you stack the over exposed and then the under exposed how do you combine in ps? and what is vignetting?

cheers

jb

[Kaptain Klevtsov]

I just stacked them in Registax. I had to open them and resave them in Photoshop as Registax didn't recognise the TIFF format at first, then save the stacked images as a TIFF. Open the new TIFF in Photoshop to de-ignette and adjust the levels and curves.

Vignetting is where the edges don't get enough light, like looking through a keyhole.

Captain Chaos

[Zeffer]

If you have at least 40/50 exposures to stack in registax - roughly how long would each exposure have to be or is it all trial and error?

[Kaptain Klevtsov]

If you use Registax for the exposures, check the histogram so that you can see if the data is going off the end due to over or under exposure. You can also use a preview function to stretch each image as you record it. Read the instructions that come with it, its worth doing.

Captain Chaos