Fire Capture settings

[SAW]

Hi,

I am really struggling to get a decent image of Jupiter in Fire Capture. I am using a Mak150 Pro, 2.25 barlow and 178MM, not the best choice of camera but that's what I use for solar and Fire Capture with no problems. I have got a 290MC arriving today.

I know it's low at the moment but I should be able to get a half decent image all I can get is a very faint image or fuzzy and too bright, are my Fire Capture settings wrong, does anyone have some base settings to work from ?

Starting to loose patients with the Mak :-(

 

 

[Grimbles]

Hi

I think your issue may be more trying to use the barlow with that scope and camera combination.

Apologies if any of the following is teaching you to suck eggs but here are my thoughts:

I use a Mak 150 and find that unless seeing is really exceptional I can get very little that is useable with a 2x barlow. I have even tried taking off the nose piece of a barlow and placing it directly in front of the ADC giving 1.5 x and this very rarely works.  The 178 has a pixel size of 2.4µm which if you do the quick and dirty 5 x pixel size you get a best f ratio of 12.  The Mak is a native f12, I use a QHY 5l- iic which has a pixel size of 3.75 µm giving me an ideal f ratio of 18.75, i.e in theory a 1.5 barlow should be ok but in reality I do struggle.

If I am correct the ASI290 has a pixel size of 2.9µm which would give you f14.5 not much of a difference.  Also don't forget if you have things like a crayford focuser , Flip Mirror, ADC in the imaging train as I have,  these will impact the Focal length and therefore the F ratio, I work at about 1900 - 1950mm FL giving me about F13.

I actually did try a barlow again last night (with Firecapture) as seeing was pretty good but gave up and went back to native Focal Length.

A powermate or focal extender may be better, but I have yet to try this.

As a starting point I would recomend removing the Barlow and trying that, you can always try to drizzle during processing to increase image scale, but again this is not always succesful.

My next move is to buy an ASI 224 which has the same pixel size 3.75µm but higher sensitivity and much less noise than the QHY5l-iic in the hope that this will improve my images.

This is what I am currently getting with no barlow and the QHY.

I Used these settings for this image

FireCapture v2.6  Settings
------------------------------------
Camera=QHY5LII-C
Filter=RGB
Profile=Jupiter
Diameter=44.73"
Magnitude=-2.51
CMI=324.1° CMII=295.7° CMIII=159.7°  (during mid of capture)
FocalLength=1900mm
Resolution=0.41"
Filename=Jup_005947_070518.avi
Date=070518
Start=005904.164
Mid=005947.173
End=010030.183
Start(UT)=235904.164
Mid(UT)=235947.173
End(UT)=000030.183
Duration=86.019s
Date_format=ddMMyy
Time_format=HHmmss
LT=UT
Frames captured=3000
File type=AVI
Extended AVI mode=true
Compressed AVI=false
Binning=no
ROI=400x400
ROI(Offset)=0x0
FPS (avg.)=34
Shutter=28.64ms
Gain=10 (45%)
USBTraffic=32 (off)
FPS=100 (off)
WGreen=11 (off)

Hope some of this helps

Regards

Martin

 

[SAW]

Best I could get tonight with the Mak 150 and 290MC.

FireCapture v2.5  Settings
------------------------------------
Camera=ZWO ASI290MC
Filter=L
Profile=Jupiter
Diameter=44.70"
Magnitude=-2.51
CMI=193.0° CMII=96.9° CMIII=323.2°  (during mid of capture)
FocalLength=1600mm
Resolution=0.38"
Filename=2018-05-15-2053_9-L.avi
Date=150518
Start=205306.346
Mid=205356.329
End=205446.312
Start(UT)=205306.346
Mid(UT)=205356.329
End(UT)=205446.312
Duration=99.966s
Date_format=ddMMyy
Time_format=HHmmss
LT=UT 
Frames captured=1000
File type=AVI
Extended AVI mode=true
Compressed AVI=false
Binning=no
ROI=600x600
ROI(Offset)=360x304
FPS (avg.)=10
Shutter=100.0ms
Gain=55 (9%)
WBlue=95
SoftwareGain=10 (off)
AutoExposure=off
Brightness=1
HighSpeed=off
Gamma=50
WRed=52

[Grimbles]

Hi

A couple of things from your Firecapture log stand out as follows:

1. FPS (avg.)=10 is low especially for the ASI290 which I assume is  USB3, what laptop / PC are you using? Obviously FPS is dependant on several factors i.e. bringing down the shutter speed will increase FPS as will decreasing the ROI but 600 x 600 should be fine. I assume you are capturing in raw and debayering in post processing?

3. Frames captured=1000, is obviously a function of FPS but 1000 is not really enough. What percenatge of these are you stacking?

4. Duration=99.966s . Unless I intend to de-rotate in WinJUpos, 90 seconds is the absolute maximum record time I use to avoid bluring due to rotation.

5. FocalLength=1600mm , really don't understand this as the native focal length of the scope is 1800mm, unless you have some form of focal reducer in your setup.  Maybe someone else can help with this? Do you have an image of your scope/camera setup?

 

Regards

 

Martin

[SAW]

54 minutes ago, Grimbles said:

Hi

A couple of things from your Firecapture log stand out as follows:

1. FPS (avg.)=10 is low especially for the ASI290 which I assume is  USB3, what laptop / PC are you using? Obviously FPS is dependant on several factors i.e. bringing down the shutter speed will increase FPS as will decreasing the ROI but 600 x 600 should be fine. I assume you are capturing in raw and debayering in post processing?

I am using usb3 although I've not got a ssd drive but I can normally get a lot more FPS when using other ZWO cameras if I imaging the sun/moon. Yes I am capturing in RAW, I have Debayer and capture colour data UNCHECKED.

3. Frames captured=1000, is obviously a function of FPS but 1000 is not really enough. What percenatge of these are you stacking?

Stacked 20% from AutoStakkert.

4. Duration=99.966s . Unless I intend to de-rotate in WinJUpos, 90 seconds is the absolute maximum record time I use to avoid bluring due to rotation.

I'll try setting the maximum capture time to 90s instead of 1000 frames next time.

5. FocalLength=1600mm , really don't understand this as the native focal length of the scope is 1800mm, unless you have some form of focal reducer in your setup.  Maybe someone else can help with this? Do you have an image of your scope/camera setup?

I'm not sure why it's coming up with this or where I can change the setting ?

 

Regards

 

Martin

Should I reduce my exp and increase gain to try and get more frames but still keeping a resonable image ?

[Grimbles]

Hi

200 frames from 1000 will give you a noiser image than say 1000 from 3000 frames but you should still see better sharpness than you are getting.  What focusing routine are you using? 

These scopes do suffer from mirror shift just about everytime you touch the focuser which is why many people ( myself included ) fit an SCT Crayford focuser via an adapter to the rear of the OTA. I focus roughly on a bright star with the focusing knob on the  rear of the OTA (you will need to tweak firecap settings to see the star properly), then fine tune with the crayford focuser, when happy i move to Jupiter and make very minor tweaks as necessary with the crayford. I have also modified a Skywatcher Focusing Motor to belt drive the fine tune knob of the crayford, so now i do not have to touch the OTA during the fine tune process which helps enormously.

With regards to the Focal Length I believe this is just calculated by Firecapture based on image size in the selected ROI etc but I may be wrong.  Check your other logs from the same session and see if they all say 1600mm ish,  again I am not certain what, if any, impact pixel size has on this calculation.

Reducing exposure and increasing gain will increase the FPS but at the expense of more noise, that said you should have less of a noise impact with the 290 than I have with the QHY.

The other obvious thing to check is collimation, if this is out, it is not as difficult to do as some people say provided you are methodical and once done should be good for a long time. I use an artifical star about 15-20m away from the OTA and double check with a 'real' star test.  There are a few how to's online.

I have to say my opinon of this scope is that it is very good and capable once you get used to it quirks and have it set up correctly, not forgetting they also need at least an hour to cool down to ambient temp otherwise images will be very blurry due to thermal tube currents.  One last thing, have you checked the front of the OTA for dew during the session as they are very prone to dewing up quite quickly I use a dew shield and dew heater which works well.

Again apologies for the long winded response and if any of this is teaching you to suck eggs but just trying to help out based on my experience of using this OTA.

Regards

Martin

[SAW]

11 minutes ago, Grimbles said:

Hi

200 frames from 1000 will give you a noiser image than say 1000 from 3000 frames but you should still see better sharpness than you are getting.  What focusing routine are you using? 

Using a Bahtinov mask on a star near Jupiter so I know I'm in focus or pretty close.

These scopes do suffer from mirror shift just about everytime you touch the focuser which is why many people ( myself included ) fit an SCT Crayford focuser via an adapter to the rear of the OTA. I focus roughly on a bright star with the focusing knob on the  rear of the OTA (you will need to tweak firecap settings to see the star properly), then fine tune with the crayford focuser, when happy i move to Jupiter and make very minor tweaks as necessary with the crayford. I have also modified a Skywatcher Focusing Motor to belt drive the fine tune knob of the crayford, so now i do not have to touch the OTA during the fine tune process which helps enormously.

Did have a crayford focuser on it but took it off didn't find it help, I still got lots a movement when adjusting the crayford.

With regards to the Focal Length I believe this is just calculated by Firecapture based on image size in the selected ROI etc but I may be wrong.  Check your other logs from the same session and see if they all say 1600mm ish,  again I am not certain what, if any, impact pixel size has on this calculation.

Reducing exposure and increasing gain will increase the FPS but at the expense of more noise, that said you should have less of a noise impact with the 290 than I have with the QHY.

The other obvious thing to check is collimation, if this is out, it is not as difficult to do as some people say provided you are methodical and once done should be good for a long time. I use an artifical star about 15-20m away from the OTA and double check with a 'real' star test.  There are a few how to's online.

Collimation is good as when I defocus on star the rings are equally spaced.

I have to say my opinon of this scope is that it is very good and capable once you get used to it quirks and have it set up correctly, not forgetting they also need at least an hour to cool down to ambient temp otherwise images will be very blurry due to thermal tube currents.  One last thing, have you checked the front of the OTA for dew during the session as they are very prone to dewing up quite quickly I use a dew shield and dew heater which works well.

I've been leaving it outside for a good 2hrs before use in the shade.

Again apologies for the long winded response and if any of this is teaching you to suck eggs but just trying to help out based on my experience of using this OTA.

Regards

Martin

 

[Grimbles]

Hi

You seem to be pretty much covered in all aspects, and doing the same sort of things as me, so am at a bit of a loss as to why you are not seeing an improvement in your images.  Do you have a raw .avi file from the camera you could upload somewhere that I can have a look at?

Martin

[SAW]

Hopefully this link will work.

https://www.dropbox.com/s/rsadkkq0fiyaoai/2018-05-15-2053_9-L.avi?dl=0

[Grimbles]

Hi

 

I have had a look at the .avi and tried to process through combinations of PIPP, Registax 6 and AS!3. I cannot get any better results than you are getting.

Looking at the avi and the outputs of processing, to me it does look like a focusing or collimation issue both of which you are happy with so I am at a loss I'm afraid.

The only other issue that looks to be apparent is the initial colour balance, are you adjusting the camera colour settings in FC to get a balanced histogram.  This is something I do (with debayer selected), when happy deselect debayer and carry on with the recording, how much of a difference this makes when recording in raw I do not know, but I do it anyway.  I did use RGGB in PIPP to debayer, which I assume is the correct pattern for the 290.

So as I said at a dead end I am afraid.

Martin

 

[SAW]

Hi,

I haven't tried adjusting the colour setting in FC, what's the best way to do this and what should I be looking for ?

I don't run it through PiPP, I've just stacked it in AutoStakkert and then tweaked it a bit in Affinity Photo.

Hopefully I'll have another go at the weekend when I've got more time and can stay up later ! I only get a short window to see it before it's below a house and I need to wait an hour or so before I can see it again.

[Grimbles]

Hi

If you click on the little cog next to the 'More' button in the 'Control' window of Firecapture a window will pop up with some sliders in, 3 of these will allow you to adjust the colour balance. Adjust them so as to get the RGB lines in the Histogram window to roughly the same level. This is what I do whether it is correct or not I don't know but it works for me.

From what you say you seem to be imaging over a roof top, this is not generally a good idea because if the roof had got warm during the day or is losing heat through lack of insulation there will be thermal currents which will make focusing very difficult and the seeing appear to be very unsteady. That said not alot you can do about the house being in the way.

Good luck

Martin

[SAW]

Hi,

I will try adjusting those sliders next time. I don't image when it's over the roof, I have a slot of about an hour or so before it's over the roof then I need to wait for it to come out the other side but this normally past midnight, too late for a work night :-(

[martinl]

The obvious thing that stands out for me is your combination of shutter speed, gain and FPS. 100ms will sample a lot of seeing turbulence and 10 FPS [max FPS = 1s / shutter speed) will not give you enough frames for Autostakkert to effectively work with. 

My process is to select the smallest ROÍ I can, then reduce the shutter speed until the FPS no longer increases (ie the limiting factor is the camera / USB 3 transfer speed) and finally increase the gain until I get a ~60% histogram. 10, or even 5ms shutter speed should be achievable and would give Autostakkert 10-20 times the number of frames to work with. 

Using short shutter speeds will make each frame noisier, but as long as your total integrated exposure is the same (shutter speed * number of frames used for final image) the resulting amount of noise would be the same. 

This is a great resource: http://planetaryimagingtutorials.com/