Auto-Flats - A few Questions

Sequence Generator
1

I have been using Flats Calibration and Flats wizard for years and take a new set of flats for every session. My fixed brightness panel means fiddling around with sheets of paper to reduce brightness for broadband, whilst SII has 120s exposures.

To make things easier I have purchased an adjustable brightness panel (Giotto) but having spent all day going through documentation am still having issues.

I have sort of got Autoflats to work but I don’t feel I am using it as intended and also have some issues.

  1. What is the process I should be using?

For now my objective is to run autoflats manually, with a set exposure range (Say 3s to 10s), and have it work out brightness and exposure within the limits.

I have read conflicting info on either Autoflats determining the correct brightness/exposure automatically or having to first set these values up manually in Filter Flats.

So, should I be able to just run Autoflats with some constraints on exposure times and have it adjust the brightness to fit the specified exposure range?

I have managed to get it to do this to some extent but, for example, when it indicates it is using 100% (671?) brightness for Ha the panel is nowhere near full brightness and it gives an exposure of 74s. However, if I run Flats calibration and set the panel manually at 73% the exposure is only 7s.

Am I doing something wrong?

  1. Camera Mode. Autoflats picks up the Gain and Offset from somewhere but no details of Mode are displayed. Is it using the same Mode as specified in the camera driver? It would be reassuring to see the mode specified.

What happens if I have changed mode during imaging - e.g I am using NB and BB filters and the event uses multiple modes?

  1. Focuser position - does the focuser return to its original position after taking the flats?

It would be useful to have some high level documentation on how to use Autoflats - different scenarios, how to approach setting it up etc. e.g. Do you need to run Flats Calibration first to set up Filter Flats values or do you just run Autoflats. Perhaps it exists and I missed it/

Just had another thought - could autoflats be extended to also create Flat Darks for each flat. Personally, I would be happy to see this just on the Export dialogue with a tick box “Create Flat Darks” with the option to Pause between Flats and Flat Darks.

2

Yes. If you’d like to use a “brightness only” scheme, just pin the exposure by setting the min and max to the same value. Somebody else recently suggested that brightness-only runs should be more intuitive to configure. I don’t disagree, but I need to think how it could be presented.

Not sure here. Maybe there was a failure setting the flat panel that is hidden from the user, but present in the logs? What are you keying off of when you note that brightness was at 100%? Are you looking in the logs? Does the UI indicate this? Can I see the logs for this run? Are they the same logs in the other “crash” post?

Camera readout mode will be, as of this moment, whatever it was last set to use. It is simplkisitc to add this, but, as always, things in this world are so settings and information dense that sometimes, it not always easy to add new settings. I’ll make sure this is added though.

Not it’s original position, but, if you start a sequence afterward, it will return to the sequence’s starting position.

No. These systems are unrelated (mostly). The ONLY cross section of the 2 systems is that AutoFlats will key off of any values produced by the older Flats Cal Wizard when it takes the first exposure. If you haven’t ever run the Flats Cal Wizard, it doesn’t matter… it may take you one extra frame to get to where you’re headed.

Possibly. All of Flat Darks are on the list to tackle in the near future.

As a note: There is a bug in the current implementation of brightness adjusted runs. I don’t know if you are seeing it or not. I have it fixed. Testing is almost complete.

3

I can’t get this to work, it will run but it won’t use the full panel brightness available and fails for insufficient light. The old Flats Calibration Wizard gives 64000 ADU in 3s for Ha with panel on max brightness. Also, I get this message when I try to run it which I don’t understand - I only have the Ha filter selected and in the Equipment profile/Camera/Autoflats dialogue I have “Capture flats for all active light events”

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A an aside the Warning box cant be closed with the X.

I also dont understand the following message when trying to run the old Flats Calibration - I have tried with and without Flats settings in the filters.

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In the image below I manually set the panel to 100% using the Flat Box control panel but once Flats Calibration started to run the Flats Box Panel got set to 0 Brightness .

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The image below shows a cosmetic bug. If I move the brightness control in Flats Calibration it also move the contrtol in the Flats Box panel but doesnt work the other way around.

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On a different topic I notice my Camera has been set to cool by Autoflats - I’m not keen on this particularly as I have been in and out of autoflats dozens of times whilst trying to get it to work.

Also noticed if I reopen autoflats it has all the old completion status and messages from the last run. e.g. there was a message saying it didnt have enough light to run successfully yet the panel was on maxiximum brightness at the time.

I have finally got an Autoflat to run for Ha using exposure limits. Not sure what was going on but I noticed the Flat Box panel controls had stopped working the brightness. I disconnected and reconnected the light panel and it worked. Perhaps its an issue with my light panel but it seems to work fine manually,

I also noticed at one point that the brightness slider within autoflats wasn’t reaching 0 or 100%, yet the Flat Box panel slider was. It all feels very brittle.

I use the slider readings in Flat Box panel and / or Autoflats. I can supply the logs from tonight’s testing but not until tomorrow.

I’m not keen on this. I usually do flats during the day after imaging and then it may be weeks before another clear night where I set up a new sequence. It would be better if the focuser position was restored to its original position before flats were taken.

I used the 8th April version and still having issues with brightness control on my Giotto panel.

4

odd for sure. I have no problem here (with that same exact warning).

This is telling you that at least one filter is currently using a brightness of 0 in order to perform the calibration. You can set these values in the Filter setup dialog by clicking the Flats button on the far right of each filter row.

This is due to the above issue. If you want to ignore those values and use your own, tick the box above the slider (in your screenshot)

I am not noticing any issues here… maybe a driver issue? Would need to look at logs.

5

I will try this again.

I have hopefully found the issue. I was used to using the defaults in Flat Calibration (30,000ADU +/- 500 ADU) and was trying to use the same in AutoFlats. I have found my Giotto has step sizes in brightness that change the ADU by anything form around 2000 ADU and 7000ADU. A large range and for some filters this range proved to be larger than the tolerance unless I was lucky.

For example, Green filter brightness 42 gave 25731 ADU and 43 gave 30276 ADU - both of which were outside the tolerance. I have the panel working in NINA using larger tolerances but still seem to be struggling in SGP. I need to do some more testing when I get chance but does SGP handle the situation that there is no valid solution?

6

Is adjusting the exposure time not an option in this case? AutoFlats will certainly handle that case.

7

It is, I was trying to use the same exposure for each filter so I only needed one set of Flat Darks to use with all 7 filters.