Hi Gunther and all.
I've tried DslrDashboard and the auto holygrail feature a few times during sunset, and it starts off working great, maintaining the reference brightness level well, adjusting my cameras setting etc to keep it at this level.
But it seems after 20-30mins or so, it gives up ramping the exposurees up. So it maintains the brightness referenve level at first, then it just keeps on getting darker and darker, without following the trend (maintaining the reference value).
I've watched all the tutorial videos I can find, along with other info, but can't understand why this is happening. I've ensureed there is enough "darktime" as the exposure time increases, even manually stopping my external intermeter to see if this helps, but to no avail. I've also ensured that my "max" values haven't been reached.
Corect me if I'm wrong, but I'm assuming this isn't the correct behaviuour. I'm assuming it should keep trying to maintain this reference value. I also tried using the plus and minus to adjust the reference, but it just doesn't seem to want to reach it.
Any ideas? Am I missing something? Many thanks! I'm using thr A7rii via wifi, tried on two different android devices. Latest software.
What shutter speed, interval did you use?
At what shutter speed did it stop?
Is maybe noise reduction enabled? If yes did you try to disable it?
Most likely the exposure times get longer and some time reach a point, where the camera does not have enough time anymore to transfer the preview and accept commands to change the settings. This is a common problem. You have to figure out how long this "dark-time" (Interval minus longest exposure) has to be with your setup.
Many thanks for the replies guys.
Very much appreciated. Firstly, no noise reduction.
I did concider the option of not enough dark time, but I'm 99% certian it wasn't that, as I was using a 6-7 second interval. I was watching the app to make sure it was receving and adjusting okay.
It started at ISO 50, 1/2000 sec shutter. Image 1
I stopped it at ISO 50 1/30 sec shutter. Image 507
As you can see, it's not a drastic or long shutter / exposure time change, so I doubt it's an issue with too little dark time.
What IS interesting is that looking back to the last 30 images or so, I can see that it IS changing the shutter speed, Imagr 466 is 1/40th. So it doesn't just give up changing, but it cwertianly stops maintaining the reference value! It's like it goes off course after a while.
That's why I was questioning exactly what is meant to happen. As it mainains it at first, but then goes off track....although while still changing the values, just way too dark. I belive the reference was about 800, and it ended at something like 90.
Eg:
Image 001: ISO 50. 1/2000
Image 200: ISO 50. 1/500
Image 300: ISO 50. 1/125
Image 400: ISO 50. 1/60
Image 500: ISO 50. 1/30
So basically, it IS still adjusting, right till the end, but it isn't maintaining the reference value.
You should be checking the reference value while shooting. I see it as a "semi automatic". Whenever I feel, the images get too dark or too bright, I use the +/- buttons left and right from "set reference" to bring the reference up or down. A higher reference value will lead to brighter images, a lower to darker ones. During a sunset with blue hour until darkness, I might be adjusting the reference value 2 or 3 times.
When I shoot in the city with artificial lights, I stop the ramping when the lights start getting too bright.
Those are all situations, where just keeping the initial brightness is not the desired result - this is, why you can carefully intervene by adjusting the reference value during the shooting.
Thanks for the reply Gunther, ohhh I was very much watching it, watching it like a hawk!
In fact I barly looked away from the app or the reference value, this is how I know it's behavior was being strange.
I could see for the first few hundred images, it was working well, it kept the value at the desired reference value of 800 or so for a long time, doing its job well. I was watching to ensure this, and checking the historgram to make sure the images looked good.
This was a sunset. But as it went on and continued to get even darker darker, its like it lost track of the reference value it was trying to hit... i was watching it drop to 700, then 650, 500, etc... I adjusted the target reference value, but it never changed the actual resulting brightness of the photo, it was targeted at say 800, but the last shots were more along the lines of 90, but it was still actively changing the exposure times etc.
This is why I'm very confused. It was tracking the desired reference well, changing exposure times etc, then the frames go darker and darker, not hitting the reference value (90 rather than 800) all while still changing the camera settings.
If you change the reference value, it will not instantly change the brightness. This only controls when to make the next adjustment.
On Sunset situations, an adjustment is always being made, when the avg value falls under the reference value. Then the next image gets brighter and the avg value therefore goes up again. Natural dropping of the light will then slowly bring it down again.
I'm still not sure, if you did something wrong or understood something wrong or the app just crashed. I didn't ever experience this behavior, maybe you just try it again under controlled conditions, say in your backyard just to gain some experience. I have no experience with Sony too, could imagine that it's not yet as stable as with Nikon.
Many thanks again Gunther for your continued support!
I just loaded the footage again, and I think you may have been right at the very start!
My interval was actually only just 6 seconds, and I can see there were periods where it was changing, and then periods where it wasn't. I can only assume sometimes it managed to change the settings before the external intervalometer set its focus locking the input, and other times it didn't.
Maybe this had some sort of snowball effect, as it likes to make small changes, it couldn't keep up in the changes and it got left behind.
I'll be sure to take your advice and practice some more with this. Leaving longer times for the dark time. I'm fairly confident with the manual method, but have some pumping in the highlights when I do it, and hoping the smaller changes will be less noticeable with this app.
Annoyingly the GUI doesn't work with my oneplus one smartphone, but works on my wifes Samsung Galazy note 6. I can't select from some pull downs. Looks like I might buy it again on my ipad lol.