OaCapture and DMK41

[Montana]

Has anyone got a DMK41 to work properly on an Apple Mac with OaCapture? I can get it to work but I am stuck with auto exposure, so when trying to the image the limb of the Sun it becomes automatically over exposed. How do I get to operate manual exposure? any help would be great as there doesn't seem to be much advice in Google or the oacapture user manual.

Many thanks

Alexandra

[JamesF]

Nice to see a post from you again, Alex   I had been wondering if the lack of solar activity had meant you'd found other things to interest you until it gets a bit more exciting again.

I assume you're using the latest release.  Is it a USB or Firewire DMK41 you're using?  I have a niggling feeling that you've been a long-time Firewire DMK41 user, but perhaps I imagined that.  And which version of MacOS are you using?

Let me know and I'll set something up so I can try to reproduce the problem.

If there are places where you think the user manual can be made clearer or expanded, please do let me know.  When you're so close to the software because you wrote it, it's often hard to see things from a "user" perspective, so I am aware that I may just have overlooked stuff that seemed obvious to me.  I did have some requests to do some youtube tutorials, but I haven't found the time so far.

James

Edited August 17, 2019 by JamesF

[Montana]

Thanks James  still solar viewing but the weather has been awful this year sadly. I am trying to get my DMK41 working on my hubby's Apple as it is smaller to take on holiday in a couple of weeks. I didn't realise how difficult astronomy is on an Apple!

We are on macOS Mojave

The DMK41 is USB

OaCapture is version 1.6.3

The exposure slider moves up and down but then auto corrects itself. So you can set it for 1 millisecond or 100 milliseconds and the image looks the same.

I hope you can help and thanks a million.

Alexandra

[JamesF]

Ok, I'll go and dig out a USB DMK of some sort from the observatory and check it out.  One thing that does spring to mind is that there may be some other auto options enabled that need turning off.

If you start oacapture and connect the camera and then select Settings->Camera, you should get a pop-up window with all possible cameras settings shown at the same time.  Can you check to see if all the "auto" options are disabled there?

James

[TakMan]

I run the FireWire version of the ‘41 on a 2016 Touchbar MacBook Pro with Mojave. The gear is away at the moment due to decorating (!) so I can’t tell you which version of OACapture I’m running, but it all works fine for me. So perhaps a USB issue?

[Montana]

Thanks for the info.

James the first place I went was the camera settings tab looking for a switch to turn off the auto exposure and I couldn't find one. I know when I first started out in IC Capture you had to turn off the auto exposure so this is why I first went to this menu tab, but I couldn't find it. I will attach a screen shot tonight when I get home, maybe you can direct me to the toggle

kind regards

Alexandra

[Montana]

Dear James,

As you can see from this screen shot there is a n area which says 'Auto on/off'' but you cannot press it, it is just writing.

Kind regards

Alexandra

 

[JamesF]

I have a DFK21 on my desk now.  I'll see if I can reproduce the issue.

James

[JamesF]

Something else to try, Alex...

It looks as though there's some sort of issue handling the "absolute exposure" setting in the camera settings pane you posted the screen grab for.  I wonder if the code is misreading the setting or something like that.

Could you try changing it from "manual" to "aperture priority" and then back to "manual" again, and close the window and see if that helps?  That seems to do the job for me.

James

[Montana]

Oh thanks, I'll try that tonight. I did see that aperture priority button but didn't know what it meant.

Alexandra

[Montana]

Yup! that works! makes no sense but I am happy  thanks a million. Need some Sun to test it out now

Alexandra

[JamesF]

Oh, excellent

If you have any problems with the software when you're on holiday, please do let me know (PM me if necessary) and I'll see if I can help.  Well, you can do that any time really, but as you're on holiday I'll try to deal with it quickly so you don't miss out on the Sun

James

[Montana]

Thanks James  
Alexandra

[Montana]

OK so this evening I tried out OaCapture to capture the Sun with the DMK41. There are a few querks and it took about an hour to work them out. I am writing this down mainly so I don't forget next week when I need it.

1. The manual exposure issue. Initially I put the camera in the PST and then opened the software. Because it goes immediately to automatic exposure it ramped the exposure really high as I hadn't found the Sun and the telescope was dark. I changed to manual exposure via the above method but when I found the Sun it was impossible to get an exposure low enough. Even with a double stack on I was at 3 micro seconds and it was just OK. Single stack was impossible. I thought this aint right, so I closed the program down and started up with the camera out of the telescope and facing the Sun so when the automatic exposure kicked in it didn't ramp it up. Then when I changed to manual exposure I had a good range and double stack was about 40 milli seconds and single stack exposure was possible. It seems that wherever the auto exposure changes to the manual exposure starts from that point when you change it. So it seems a bit random and exposures are not the same each time, weird but workable.

2. the next problem was I took several AVI and checked them for processing on my Windows PC and ran them through Autostakkert and started to post process. Nope, it seemed to record on a very high compression and the pictures were very pixellated. Next try I found in the Capture settings you need to tick both boxes, Windows compatible AND no compression. It worked.

3. It doesn't seem to remember settings once the program is closed. I need to remember to set the file path for capture, tick limit to 1000 frames and check the two boxes are ticked for the AVI settings.

4. I must remember to tick the frame limit as there is no way of knowing how many frames you are capturing as there is no counter, if you don't set this limit you would need to calculate with the calculator how long you need to capture for with your frame rate and use a stop watch.

Very querky but at least I did it and with the Apple being the only computer coming on holiday next week at least I can now snatch it from the hubby and take a quick capture with the PST. Here is my final effort, very pleased with myself and thank you very much James

oaCapture-20190826-180145_f colour by Alexandra Hart, on Flickr

Alexandra

[JamesF]

Thanks for the feedback, Alex.  I think a few of your issues stem from the fact that I have dithered numerous times over whether the software should set the camera controls to its saved values when connected, or whether it should show what values are currently set.  Perhaps I should make that configurable.  The fun really starts when the current settings have no actual value for a newly-connected camera.  Thinking about this too hard usually just makes my brain start dribbling out of my ears.

The windows format avi thing is a nasty gotcha.  Windows appears to have a subtly different format from MacOS and Linux, so if you're moving between them it can get a bit messy.  I think my preferred option now is to abandon AVI altogether and use SER instead, but certainly for the time being it's probably far more sensible to stick with what you know.

Not sure I fully understand your point 4, but if you can explain in a bit more detail when you have time then I'll try to make it more intuitive.

Very pleased to see you have a worthwhile image out of it in the end though.  I hope you both enjoy the holiday and see lots of sun :)

James

[Montana]

Thanks James, you are amazing really because I never thought it possible to do this with a Apple computer.

Point 4. Usually in firecapture or ICCapture there is a little counter/clock at the side, so when you press the record button a little dial starts counting in real time how many frames you are capturing. So you can sit and watch and manually click stop when you hit 200 frames, 800 frames, 2029 frames if you wish. In this version with no counter you are blind. If you forget to hit the limit button and set where you want to stop the recording then you sit there and think, hmmm when did I hit the record button, I wonder how many frames I have recorded? The only way to tell is to hit stop and go and view the file in Autostakkert or Registax. It would be a nice extra feature if you ever got round to it, for forgetful people like me  

Well done though, very pleased with my image, so I hope the Sun does come out in the Pyrenees next week

Alexandra