HI,

I'm trying to do a time lapse from sunset to sunrise with the Milky Way visible during the night and would like to ask some questions on that.

Is it possible to set or calculate what exposure settings qDslrDashboard an the LRTimelapse function will be at during total darkness? Lets say I know that during astronomical night I want to use an exposure of something like 20 seconds and ISO 3200 at f/2.8, is it possible to set that? I know I can set maximum exposure time and ISO, but how can I know what settings will be used? If I take a reference/sample image during sunset when I start the sequence, do I need to lower the reference manually during the night to get really long exposures for the Milky Way?

Also, since I'm both covering sunset and sunrise, do I need to change Auto Holy Grail direction during night from sunset to sunrise, or can I just enable Auto direction? I would like to automate as much as possible so I just can set up the camera and leave it through the night and get it back in the morning when all is done.

Thanks,
Göran

Hi Göran, you cannot know which settings exactly will be used during the night, since the app doesn't know about the conditions then. That's the good thing with this adaptive approach that uses the histogram to analyse the sequence. But it's not necessary to know it since qDDB will use the right order when changing the parameters. It will start with exposure time and then at the end to the ISO as high as it's needed.
It's recommended to have a look from time to time and adjust the reference value, otherwise, if it get's really dark, the images might get a bit bright.
After the ramping for the sunset is finished (end of nautical dusk) you can turn off the auto holy grail and switch to sunrise. Then turn it on again. For best results, I'd not leave it totally unattended while sunrise then too and check the reference, otherwise the images might get too dark.
I'd not recommend Auto-Direction, from my experience it's not really rock solid.

Holy Grail shooting is not 100% setup and forget, I'm afraid. But if you manage to get a great result then you'll definitely be proud of it.

This post was last modified: 2017-06-12, 20:55 by slabkoff.

From my POV, you probably need to do this in 2 steps - the Sunset section and the Sunrise section. One or two frames during the switch over won't ruin your TL sequence. I agree w/ above - I don't think this can be a "set it and forget it" thing.

The real trick for me, and this is a follow-up question, is this: I've seen TL's of the whole sky that has appeared to be done w/ some kind of wide angle lens that shoots from horizon-to-horizon. It does not look like a fish eye, but I can't image any other kind of lens that could do something like this. But, again, it's a flat rectangular image sequence. It captures the entire sky at one time. Anyone know if this is a Fish Eye lens? Anyone know what I'm talking about ;-)

Hi I have a similar setup: sunset to milky way. From what I understand the preferred method is to use auto holy grail during sunset and then switch it off for full milky way shots with preferred settings (for me usually 20" f/2.8 ISO3200 with Sony a7ii).

Can you please just give advice on how often to check for references? Is there a suggested number of shots/time interval?
Also, if I feel I have to adjust reference + or -, how much should I go up or down usually?
Thanks

Only change the reference value, if you feel the images are getting too bright or too dark. Usually I click once or twice on "-" if the images are to bright and vice versa. After doing this wait - the changes will not take effect immediately.

So for this shoot, would you set the interval to be what you estimate the max exposure time + a few seconds for wifi transfer? 25 seconds maybe? Wouldn't you want it lower to get a smoother video? Or would you adjust it (interval) over time?

If you use a shorter interval, you'll need a faster lens. Of course then everything runs slower.
Another option would be to ramp the interval, that means use a shorter one for sunset and then do a smooth transition to a longer one for the milky way. You could do this kind of interval ramping with qDslrDashboard, but its internal timer is not very accurate. A better choice would be to use the LRTimelapse Pro Timer Free for the interval ramping: https://lrtimelapse.com/lrtimelapse-pro-timer-free/

oh cool, i didn't see interval ramping was a feature of that ardunio thing. I'll have to try to build one of those after my next trip.