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I Have Issues !@~#!


Allan the Plumber
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Hi can anyone help? :facepalm:  


 


As advised by Ron at SGL last Saturday asking if anyone knows what I'm doing wrong or have I a damaged or incorrectly working piece of equipment?


 


Please find below a series of shots that have been processed in DSS then adjusted with PS6 to highlight the issues I'm having. I have increased gain to try to highlight this issue but I think you should get the picture.


 


Firstly equipment I'm using:-  an astro modded Canon D1100 with Skywatcher 0.9 Coma corrector, as well as a SW light pollution filter on end of that


 


Scope is a SW Explorer 200 DPS


 


All subs are at 400 osi and between 200 to 400 seconds darks are same day taken same temp, the  DSLR  is same orientation for darks as the subs, the flats and Bias are taken from stock but where only taken about a month ago beginning December


 


On PS I'm using GTX to help with gradient as seen in M42 image


 


Help!!! its seems that in the last few months this banding and gradient is creeping in I'm unsure why!! Even when cropped out the image seems to have a lot of noise. I do have light pollution but the house blocks a lot facing North towards Nottingham most of my images are taken facing SE over towards Radcliff on Soar PowerStation but this is hidden


 


I'm not really up to speed with PS processing yet, but think I have master the basics concerning DSS  can anyone help


 


Just another quick ask I'm not sure why (WB issues??? ) but when every my image in DSS is processed its very washed out but longest exposure I'm doing is 400s again is this a light pollution, camera or  processing problem


 


Thanks for assistance


 


Allan


http://flic.kr/p/jopMJ7


 


http://flic.kr/p/joqWBC


 


http://flic.kr/p/jonHW2


 


http://flic.kr/p/joqWTu


 


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Not really used to DSLR, but stock Flats, that is new one on me :(  I thought your could only use stock bias frames???

 

Good point. You should do flats after every session. Dust bunnies will be different every time, especially if your camera has an ultrasonic cleaner.

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Not really used to DSLR, but stock Flats, that is new one on me :(  I thought your could only use stock bias frames???

I do see your point but I don't think it's dust bunnies that causing the issues :blush:

 

Its seems like light or something is getting into the image at the bottom plus it appears the gradient has got worse since I got the coma corrector would this be effected by stock flats??

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I do see your point but I don't think it's dust bunnies that causing the issues :blush:

 

Its seems like light or something is getting into the image at the bottom plus it appears the gradient has got worse since I got the coma corrector would this be effected by stock flats??

 

 

no i was not saying it was your problem, but just pointing out you cant have stock flats really.  Only bias :)

Edited by Sheila
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Guest Kheldar

I do see your point but I don't think it's dust bunnies that causing the issues :blush:

 

Its seems like light or something is getting into the image at the bottom plus it appears the gradient has got worse since I got the coma corrector would this be effected by stock flats??

 

Try stacking without the flats and bias frames

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have you tried covering the viewfinder while taking your shots

 

ther should be a cover on your camera strap

 

Steve

 

 

Hi Steve do you mean the eye piece or the screen on the back of the camera ?

 

I have turned off screen display

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Hi Steve do you mean the eye piece or the screen on the back of the camera ?

 

I have turned off screen display

viewfinder is eyepiece that you look through in case of light leakage i suspect????  they usually supply a cover attached to strap when you buy

the camera... it clips over it

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I'll be honest I can't see anything there I would not expect to see. If it looks different to other images you have taken I would say it's either dew / moisture either on the mirrors or even the camera, or it could be moisture up in the atmosphere. 


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You mention its astromodded. Is the replacement filter correctly placed?

Bought the camera astro modded from "Cheap Astrophotography " they advertise on Astro buy and sell . haven't heard of any problems with them

 

Was a brand new camera has only 1200 shutter clicks aprox to date

Edited by Allan the Plumber
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I'll be honest I can't see anything there I would not expect to see. If it looks different to other images you have taken I would say it's either dew / moisture either on the mirrors or even the camera, or it could be moisture up in the atmosphere. 

Checked main mirror during night and could see no moisture on mirror have dew bands on guide main OTA and finder my previous images didn't seem to have this amount of gradient  problems

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Just had a quick search around and some threads mentioned a sticky mirror. Do you use live view mode to take your subs or does the mirror flap with each shot? Have you tried taking daylight photos with it?


Edited by xanthic
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Just had a quick search around and some threads mentioned a sticky mirror. Do you use live view mode to take your subs or does the mirror flap with each shot? Have you tried taking daylight photos with it?

No I use APT and set up the subs darks etc.

 

I only use live view when setting up scope to confirm eqmod is tracking to the correct location in sky, I then take a single shot making sure target is centred and focused

 

I then leave APT to do its work returning to cover scope with lens cap when subs have finished I don't even stop scope tracking I leave it tracking with lens cap on taking darks

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Al - you also use APT right? Have a read of this one too - http://www.iceinspace.com.au/forum/showthread.php?t=60913

 

Hopefully that's the cause and resolution.

Looks like it might be issue have just checked APT can't seem to find mirror lock on camera but see that the anti vibration pause is already set to 0 seconds

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I think it's got nothing to do with anything except how many bits of resolution you are capturing and then doing your processing in.


 


When you stack do you save FITS or TIFFs?


 


Do you do any pre processing in DSS?


 


If so, do you save as 16 bit TIFF with changes embedded.


 


Do you read into PS as 16 bit or 8 bit?

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I think it's got nothing to do with anything except how many bits of resolution you are capturing and then doing your processing in.

 

When you stack do you save FITS or TIFFs?

 

Do you do any pre processing in DSS?

 

If so, do you save as 16 bit TIFF with changes embedded.

 

Do you read into PS as 16 bit or 8 bit?

Okay Noel as asked

 

Saved in Tiffs

 

No pre processing in DSS

 

16 bit Tiff when saved from DSS with "apply adjustments to saved image"

 

processed in PS with 16bit channel

Edited by Allan the Plumber
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