Imaging the eclipse ST80 + dslr

[Magnus_e]

When i have started doing astrophotography and there is an eclipse, i must make an attempt at imaging it.

My equiptment is the Orion ST 80, Orion solar filter http://www.astroshop.eu/mounted-foil-filters/orion-4-id-e-series-solar-filter/p,33602 , and the celestron avx.

I think this should be a good setup for imaging the sun. "I also have the solar filter cardboard glasses so i don't go blind"

Only consern with the equiptment is that i'm not shure how the eclipse will loock using the solar filter.

But how to do it?

1. The imaging part:

Should i use the video funktion of my dslr or is it easier to get a deasent still foto?

I guess there is no point trying to stack

[Magnus_e]

Lol, hit wrong button.

Continued:

no point trying to stack as the eclipse moves during the session.

[jambouk]

I'm aining to do something sinilar; ED80 and dslr and white light solar filter. Was thinking of taking lots of shots throughout the eclipse and then potentially making a time lapse video afterwards.

[Magnus_e]

A timelapse sounds like a good idea.

Have you imaged the sun before? I'm wondring about how to achive focus and how to get deasent tracking?

As it's sunlight there are no way of polar alignment and such. Is it sufficient to sett the latitude and point the mount north?

I found the wikipedia link and it looks like my part of the world can wiev the eclipse at about 8:45-11:10. Looks like it's 30min earlier in the UK.

I took this info from the animation in the wiki link. I thought an eclipse lasted for a shorter ammount of time, am i reading it right?

[Magnus_e]

Forgot the link http://en.wikipedia.org/wiki/Solar_eclipse_of_March_20,_2015

[jambouk]

You could polar align the mount the night before; and do a star alignment and then park it. Leave it outside all night under covers, then un-park it in the morning... Sorted.

I've imaged the sun before with my mak and a whilte light filter and a dslr. Getting focus is pretty easy as there are usually sun spots. If you can connect the dslr to a laptop then you could use a longer usb lead and look at the laptop somewhere more shady than sat at the telescope. Else make a hole in a big bit of card, and put around the scope somewhere so it casts a shaddow over the dslr.

Ine thing i did find last time i was imaging the sun with the dslr, even with the white light filter the camera was getting hot, and it disconnected a few times and i winder if that was because the sensor was getting too hot.

I've just ordered a second hand book off amazon as i want to make aure i don't fall in any well known traps.

James

[Magnus_e]

I have a laptop and backyard eos, so shade is no problem.

I had issues with my camera getting to hot when i used to have magic lantern on it. With the sun it's more scary if i continues to rise in temp with a telescope and all.

As it's in daylight it's probably not so cold, so i can be outside keeping an eye on things Last night that i was doing ap i set up windows remote asistance so i could keep an eye on the laptop from my desktop inside.

No point standing outside looking at a camera taking 10min subs in sub zeero temp

[jambouk]

Indeed

[Magnus_e]

Have done some more recearch and found a great site for checking the duration an local time for the eclipse. www.timeanddate.com/eclipse/in/uk or any other country code.

Where i'm at the eclipse starts at 09:47, reaches max at 10:54 and ends at 12:02. In other words a duration of 2h15min. The eclipse reaches 90% in my location

Going to try a 45sec timelapse with a framerate of 24fps. Think i have calculated image rate. (135min * 60sec) / (45sec * 24fps)  = one image every 7.5 sec. A total of 1080 frames.

The had rised at 8:30 in my spot, so i'll have atleast one hour to set up. Can hardly wait

[jambouk]

Work out how much storage space you need too; if you have plenty i'd capture more data than necessary.

It might be worth while doing a test run a few days in advance to work theough your set up and image capture, and then the processing and look at the resulting video to see if you should do anything different on the big day.

Good luck

James

[Magnus_e]

The size of the raw files is ~18.5MB i think. That's about 20GB for 1080. I have a 64GB memcard, so i can take a lot of frames.

Does BackyardEOS "operate" faster if i tell it to save to camera, or does it download the images anyway to preview?

Not shure if i'll get time to do a test run. The forecast is ok on sunday, so i might be able to test it out then.

Do you know if i have to use different exposures for the beginning / end and the maximum of the eclipse? That would complicate things a bit. And no way of testing in advance.

Maby have the sun exposed on the bright side before i begin?

[jambouk]

There must be info out there about what settings; auto setting?

If you have it too bright (over exposed) you'll burn out any detail, like sun spots.

I think some software can standardise the exposure settings when making a time lapse video, it did that for my jupiter time lapse, but can't remember off the top of my head i used, maybe the PPplanetary one.

I don't know either about the backyard question. Again if you could do a test (day time or night) and just look at where the bottle necks are in data transfer.

I still think we are going to end up with hot sensors, which may cause problems.

James

[Magnus_e]

I found a great link on how to do this. It does requre an calibration test before the eclipse. Testing exposure and such.

Glad i found it, because i did not realize the solar filter has to be removed when the eclipse is at its maximum.

It says that all parts of the partial eclipse is at the same brighness, but the sun’s corona has a surface brightness a million times fainter than the sun’s visible disk or photosphere.

Here is the link: http://www.nikonusa.com/en/Learn-And-Explore/Article/h20zakgu/how-to-photograph-a-solar-eclipse.html The instructions are at the end.

Have to do some more reading to make shure this applies to a eclipse with a maximum of 90% It seams like it's talking about totallity, but then you must be on Svalbard or something.

Now i will just have to take a day of testing before the big day 

[jambouk]

I don't think you should be removing the filter if you still have 10% of the sun preserved. Sounds like a recipe for disaster.

James

[Magnus_e]

It does say that "all parts of the partial eclipse is the same brightnes" But i vill use the tip about finding the expoture. The software i'm using lets me store image plans. So i'll save a eclipse max plan that loops from 1/30 to 1/1000 and then stop it when it looks good. Then make a shorter loop with three exposures close to the target and a 5sec pause at the end. Then resume the sun timlapse when maksimum eclipse is over.

I'll test it out on the sun on test day.

[glowingturnip]

looks like I might be able to have a go too, with the school's scope.  Was thinking along the same lines, use a DSLR for full-disc, and set it to say capturing frames every 5 or 10 secs to APT, then can make a time-lapse of the whole thing, and take the best few near maximum for stills.  Will have to persuade my boss to let me have the morning off.

Just thinking about exposure - since it doesn't reach totality where we are (going to be pretty good in Norway though isn't it ?  think it's about 75% here), if you consider say a square inch, for want of a better word, of the solar surface that isn't covered by the moon, that's still going to be seen by the camera at the same light intensity regardless of the rest of the sun being covered or not, so increasing the exposure times will only burn that out.

Using APT or BYE probably a good idea so long as it can cope with the bandwidth - more storage space on the laptop, and you can tweak the exposures on the fly as the subs come in.  Planning on doing a dry run this weekend if we can see the sun.

Finger's x'ed for good weather.

[jgs001]

Why would you need to shoot a frame every 5 to 10 seconds ? Why not every 5 to 10 minutes (the S@N article suggests 10 to 15 minutes apart) ? that's what I'm planning on doing. I'll be using my ED80 on a camera tripod... I can't mount up my HEQ5 in my office, however, a PA using a compass for North, and the Latitude scale on the mount will suffice (you may need to tweak the tracking later on, but if you're using 10 minutes between exposures that's really not a problem). I'll have to shoot through the window... no choice... but may set it up for window cleaning shifts the glass all the way out the way, as it moves the glass out the way. Fit the filter, set the camera to spot metering, and take a meter reading... As I recall, I normally go for about 1 to 2 stops under exposure. I typically colourise my solar images an orange colour. 

Don't forget to check your solar filter before use to make sure there's no damage, keep your finders covered/removed/with a filter on.

[jambouk]

If you shoot once evety 10 minutes, over 2 hours one will only end up with 12 frames which wouldn't make a very good time lapse video.

[glowingturnip]

was thinking 5-10 secs so that I can take the best ones near to maximum and stack them together for some quality stills without there being too much movement in the shadow between exposures, that's the theory anyway.  Would prefer to have too much data than not enough.

Will be using the school's Lunt, which I've not actually used before

[jgs001]

That'll work... I'll be working, so will have to steal moments as and when.. and the S@N guide seems like a plan for that

[Dave In Vermont]

I, for one, will enjoy seeing your results using the Orion solar-filter. I have one also. They are a different creature than the Baader film in that it gives an orange-yellow hue to the solar disk. And the ST80 is an excellent choice of scope - or the ED80 for that matter.

I'm not entirely positive, but I've heard that this film Orion is using is coming from Thousand Oaks in California. Seems they've been making solar-film for many years, but I note we only hear of the Baader film.

Clear & Sunny Skies,

Dave

[Magnus_e]

I have a great weather forecast this weekend.

Going to try to polar align on saturday night, and have a test run on sunday morning. Maby get time for a dso on saturday night.

Looks like my imaging location is just short of the "more than 90% totality", so i'm in the good part of "up to 90%".

The forecast for 17-19 march is dark clouds so i hope it clears up for the 20th. Deserves some lucky weather after all the clouds the last months

[Magnus_e]

Rehersal completed.

I got one frame every 5 second for 55 minutes. There was some clouds at the end but i didn't let it stop me.

There were no issues with overheating, and i don't susspect it to be over the 2h15m of the eclipse.

I haven't done any post prossesing yet, except for letting pipp crop the frames. I have a program caller RawTherapee that can open raw files and do corrections in a batch job. It can save the result as jpeg, tiff, png and so, so i can use it before pipp.

It would have been fun to try to stich the frames i have into a timelapse. I would get 27sec @ 24fps. Only thing i noticed was that the frames prosessed by pipp had the syn slightly of center. If i scrolled through them in image viewer by rapidly pressing nex i could see the sun jumping around. Does anyone have some tips on making the timelapse. Could thake some time if i have to center all the frames myself Maby i can review the settings i used i pipp and get a better result.

There are of course forecasted dark clouds on all of the 20. march, but ill try to stay hopefull.

Have anyone else got to do some tests? I'll add the first and the last frame that came out of pipp.

[glowingturnip]

there's an option in PIPP to center the object, it's on the same tab as the crop tab, so try that

our dry run was a flop - sun shining brightly with some light cloud as I was walking to the obsy, as soon as I got there it blanketed over, couldn't even get aligned on it

[Magnus_e]

our dry run was a flop - sun shining brightly with some light cloud as I was walking to the obsy, as soon as I got there it blanketed over, couldn't even get aligned on it

That's a shame. Hope you have better conditions on the big day. My forecast has been changing betvean light an dark clouds, and has just changed to rain.

I'll check and see if i had the center object checked.