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Mav359

Can someone explain to me these settings......

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Sorry for all the questions but ........

I have a QHY8L which is cooled.

In EZCap (for example) there are three settings....

i) TEC Off = i figured this is just to turn the cooling off

ii) Manual = Does this mean i can set the temp i want the camera at????

III) Auto Control = I figure this is just as it says and will automatically control the temp of the camera

There are also two sliders

i) = On the left, this is a percentage. A percentage of what???

II) = On the Right, a number ranging from -50 to 30

I think that what im seeing is this....

a) the 53% slider is relevent to the power measurement on the bottom bar. Whats the benifit of changing the power?

B) the -33.1c is the temp of the sensor (seems cold) & is that temp as a result of the slider set to -10, correct? If so why would you set it as cold as poss?

Lastly in Nebulosity (which i'd rather use) i can set the following...

i) AMP Off - dont understand this one

ii) Enable TEC & there is a box allowing me to adjust from 1000 to -273, is this the equivalnt of the slider on the right in EZCap?

Cheers in advance for any help you guys can give

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hi in ezcap temp control click auto control ,on the right hand side set the temp that you want ie -20 away you go when your finished for the night click tec off before you shut down the cooling has to come up to ambient temp or you will damage camera, sorry cant help with nebulosity camera control i dont use it although i use it for stacking etc i find ezcap easy to use for capture

mark

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Ive been playing with this in Nebulosity and its actually very easy to set the temp. Quite impressed actually set it to -25 and it didn't wander more then half a degree from the target.

Is -25 too low do you think? i have put together a library of Darks all at -25.

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I think the point was that it is 20 or 25 degrees below ambient temperature, not minus 20 or 25 degrees C

Helen

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So if its 2degrees outside temp then me setting it to -25 means the camera is operating at -23, right? (did seem a bit cold)

Nebulosity has a tempreture readout which the entire time the camera was running read -25. Does that mean that my Dark library isnt accrate as the temp during the day changed.

It certainly looks in Neb that the temp reads the temp of the CCD in degrees.

May have to re-think this Dark library

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Thats obviously with now camera connected :shocked: during operation though it stayed at -25 and in brackets displayed the cooling power %

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this is from the manual

Clock / TEC display: In the control panel, Nebulosity can display a small clock

that will show the current time in a range of time formats or show the CCD's

current temperature.

I read that as the actual temp of the CCD, my thinking was that if i could always choose the temp at which the CCD ran i could create a dark library now to save time later, all i had to do then was take my SUBS once the camera reached the desired temp.

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this is how i see it i maybe wrong but

sorry if i didnt explain it properly, so the camera is a set point cooling camera if you set say -25c and the outside temp is 2c the camera ccd chip is operating at -23c ,so the camera needs to operate at between -15c to -20c so you set the right hand slider to account for the ambient temp thats why the temp slide goes down to -50c regarding dark librarys they maybe wrong but a few degrees out wont make a lot of difference what i do is do some darks at beginning of imaging then some at the end take a note of temp ie 4c outside - 24c = -20c darks then i can use them again bit of a fig but it works for me

hope this makes sense

mark

ps you could bad pixel mapping instead of darks ive not tried this yet still trying to get my head around it as soon as i do i will give it a try

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There is a QHY8L review ( two parts ) on youtube which if I remember, cover the settings with regards to the TEC set point cooling. Hope it helps :)

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Ther are by astronomyshed and are the first two which pop up if you type in QHY8L into the search box ;)

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Hi Guys

I have just had confirmation from Craig Stark that in Nebulosity anyway the CCD temp displayed is the actual temp of the CCD (reported to nebulosity by the camera). So -25c in this case is the actual temp rather then ambient subtracted.

So in my head now it deffo makes sense to create a dark library if you can regulate the temp of the camera so that all SUB's are always taken at the same temp then you only need match the SUB's to the MASTER DARK exposed for the same length of time.

-25c may have been a bit much so i am going to start again & drop the temp to -20c as mark suggests. I think i will increase the amount of exposures to 30 and increase the range of exposure times as well.

Gives me something to do as opposed to cursing under my breath whilst watching the cloud roll by :grin:

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thats interesting might give nebulosity a go at capturing instead of ezcap let us know how you get on with it and your darks library it could save a lot of time as you said

mark

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Will do

I plan to get them done over the next few days. The way i see it is if your exposing for 20mins then your DARKS need to be that length too & if you want 20 of them that's 6.6hrs of DARKS. There are obviously very important but my god are they boring..

If you do your DARKS straight after your session then the chances are that its nearly morning and all you want is bed rather then sitting out with kit waiting for DARKS to finish. Not to mention if you have a regulated camera and use Neb then you probably already have that data recorded anyway, why do it twice.

i think i will stick to the 20 exposures and include the following times.... 1,2,3,5,8,10,12,15,20,25&30

A master BIAS can be re-used so with a DARK library in place it means the session consists of taking your SUBS which is the bit you want to spend your time on and then gather your FLATS 20 of which doesn't take very long anyway.

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ive been playing with the capture side of neb today lot easer to build a dark library so guess what im doing lol

mark

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mine going now, should be finished thursday

have to say i do like neb i use it for everything now upto & including the pre-processing (stacking, aligning etc). Then i move to photoshop for processing.

I'm going do re-do my BIAS master as well, cant remember if they are temp dependant but it only takes a couple of mins

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Thats it done

I now have completed my dark library i have masters for 1,2,3,5,8,10,12,15,20,25 & 30mins @ -20c. The camera's ability to maintain its tempreature is great it hasn't wavered more then .5c either side of the -20c mark.

19hrs40mins of data that i dont have to collect ever again :grin:

I have also re-done my Master BIAS @ -20c as well leaving me with just SUBS & FLATS to gather going forward.

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Thanks Sub Dwarf,

I received my new QHY8L today,long delays in delivery to Western Australia! I sure am looking forward to the cooling.

The Neb 4 temperature  report you confirmed with Craig Stark is as I suspected as when the usb cable is connected to the camera but the camera has no power Neb reports -273 , absolute zero, nobody has been there.

I only used Ezcap to select Auto, and set the target temperature to -5 in Neb. This with ambient temperature  of 28, it needed 68%power to get to that target.

In your dark library only one exposure for each duration, up until now I have taken 10 dark frames for each camera setting and then stacked them. As Craig Stark has said, a single dark just introduces the dark frames noise to the lights.

Another question, do your darks work for varying camera gain?"

I sure have lots to learn.

 

Chris

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3 hours ago, muletopia said:

long delays in delivery to Western Australia!

I think anyone expecting deliveries from China (or indirectly from suppliers who only drop-ship orders from Chinese suppliers) will be in for long delays. Some countries have stopped accepting parcels and letters for China as there are so few flights still operating to there.
I've got a couple of Aliexpress orders that have been stuck "Awaiting shipment" since the end of January.

  • Sad 1

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I was lucky,shipment before corona.

I use Nebulosity 4 for capture control, does Neb 4 set TEC protection mode? Last night, all clouds so I took darks (10 off 600 second frames,see my previous post in this thread) ,set -5 degrees for Neb with an ambient temperature 20-25 degrees. The power % did not go above 68. I respect Craig Stark so it would not surprise me if this feature is included for the QHY8L.

Does any one have a definitive answer?

Chris

 

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