PD1 camera and large DOB

[bomberbaz]

Hello all. 

Title says it all and details in my signature.

Does anybody else have a similar setup as I am struggling a little with exposure. I have done lots of tweaks of the camera settings but my best effort has been the image below. (M5)

This was captured using smartcap btw and processed using registax. However I reckon its PD camera settings and not the programme thats the issue here.

Not that its all about imaging, I want to be able to observe from my PC chair and with results like this, its getting a little frustrating. I am even considering getting a frac on a goto mount instead and simply selling the dob but I think this would be a bit whimsical so must carry on trying this out first.

Any ideas on settings etc.

[Carl Reade]

Hi have you manually adjusted the colour during the daytime so it looks natural?

[bomberbaz]

good point Carl, do you mean connected to the dob or with just a std lens fitted?

Also I am wondering if the glow is partially down to streetlamp glow. I have a long dew shield fitted but maybe that is part of the problem, think i need to get out to a darker area to try it out.

[Carl Reade]

Yes connected to lens or scope. Then adjust the white balance manually then save. Add to your checklist when using that's its set to manual at night

LP can also be an issue, I have to use a Skyglow filter because of sodium lights where I am.

[bomberbaz]

I forgot I have a LP filter in my box, dohhh!

Also how exactly does the e shutter speed affect the results. Just playing in my house now makes a huge difference to what i see but of course this is in daylight, I dropped it to 1/4000 to get a decent image but on the recomended settings it says set to 1/50. I am assuming the lower the setting the more sensitive it is right?

I am taking notes and its a good old learning curve alright. I will give it another go tomorrow night and take more time with the settings.

[Carl Reade]

Hi shutter speed is the main functions you will use. Essentially it controls the amount of time the chip is exposed to light. To high and the image will be far to bright or even white. To low and you may not see anything.

Yes your right the slower the setting the more light is exposed to the chip. In daylight thousands of a second is normal but night no use you then go slower until you get an acceptable image.

You will find the moon and planets need to be fast as they are bright and DSOs will require a number of seconds.

Hope that helps.

[bomberbaz]

Hi shutter speed is the main functions you will use. Essentially it controls the amount of time the chip is exposed to light. To high and the image will be far to bright or even white. To low and you may not see anything.

Yes your right the slower the setting the more light is exposed to the chip. In daylight thousands of a second is normal but night no use you then go slower until you get an acceptable image.

You will find the moon and planets need to be fast as they are bright and DSOs will require a number of seconds.

Hope that helps.

Thanks Carl. I am hearing the sound of many pennies dropping as I read through this and other threads and re-read the manual.

I think next time I will park the scope close to where my pc station is, focus in on just one DSO (M57 is favourite from where I am) and go to work on it. I will remember my LP filter this time and work slowly from the bottom up until things seem acceptable.

So soon you will see either pin sharp images of the night sky or pictures of a smashes up PD1       

[Carl Reade]

Here's a guide to sense up exposure times in seconds or a way of working it out,

Camera lowest exposure 1/50 of a second then you go into x2,x4,x6,x32 up to x1024.

1/50th sec as a decimal is 0.02

Then multiply 0.02 by the senseup value,

Senseup x32 is 0.02x32=0.64 second

Senseup x128 is 0.02x128=2.56 seconds

Senseup x1024 is 0.02x1024=20.48 seconds

Hopefully useful it gives you an idea of when the screen will refresh and exposure times. Effectively the camera is stacking the 1/50th exposure x32 times or what ever its set at to see more.