rawopint.lua: Fast, accurate intervalometer with raw exposure metering

Mlapse

I was just wondering why there was this exposure difference from first shot, and if you use a standard frame that would probably increase.

I have no use for adittions, keep it as is.
but like you wrote, when you start at night it might take a few shots before the script has settled.

c_joerg

Mlapse
I was just wondering why there was this exposure difference from first shot, and if you use a standard frame that would probably increase.

This happens, for example, when starting the script in AV mode at night. The longest exposure time is then through the Canon firmware 1s. If the longest exposure time in the script is 4s, then it takes just a while increase to 4s. You can work around this by starting the script in M with 4s.

Greater differences after the first shots are also there when the over and underexposure controls take care.

Mlapse

Greater differences after the first shots are also there when the over and underexposure controls take care.

And that is probably what i noticed, my first shot at night was seriously overexposed (according to the log iso400/1sec/f3 and that can't be correct), consecutive shots were timed 1.3sec (same iso/f) and higher, but were not overexposed and still very crisp.

Mlapse

I'm making outdoor shoots and ran into this snag with the script that my limited knowledge can't solve.

If i start (daytime) I usually first have a series that start darker, gets lighter and drops after 5-10 shots to a stable result. If i did a test shoot before the 10th frame is then close to the same exposed picture as where the previous series ended. My interval times are mostly between 10 seconds and 1 minuut.

For a standalone project this is no problem, i just throw away the first few pictures.
However, could I create settings in rawopint that mimic the canon firmware as close as possible?

The reason I ask is because I sometimes want to exchange the sd card mid-shoot or have to restart for some reason and i try to avoid losing 5-10 minutes if possible.
I have been using Ultimate intervalometer like that and, because it relies on the canon firmware there is no real difference in exposure between 2 series.

And although i'm very pleased with that script I've been testing rawopint mainly because of the capability to define max and min exposure.
It gives me the possibility to get better night shots with less noise from small sensor camara's that cap off at 1 second in canon's firmware and to block long exposures (30 sec) on the M10.

I have been trying to minimize the lighting differences by changing ND_value_apex96, BV/EVshift% BV/EV shift base and meter height and wide without getting the effect I was looking for...namely a picture that start with almost the same settings as the last one of the previous series.

Or am I chasing an impossible thing here, because the whole metering concept is different?

c_joerg

MlapseIf i start (daytime) I usually first have a series that start darker, gets lighter and drops after 5-10 shots to a stable result. If i did a test shoot before the 10th frame is then close to the same exposed picture as where the previous series ended. My interval times are mostly between 10 seconds and 1 minuut.

You should post a log file that make it easier to understand whatâ€™s going onâ€¦
In normal cases I never have this problem. In the following cases I had the situation:
1) I used spot measuring in AV mode but script used the whole scene (90%) for metering.
2) If I take pictures against the sun and then overexposure control in the script reduces exposure.
On witch mode you are running and which exposure method you are using?
What about underexposure control? In my case is always disabledâ€¦

Mlapse

I have the cam in P setting so i can fix color tone/iso and a few other things
1)I use center weiged average
2)Testing only with the sun (or without at night)

I have not changed underexposure control, as soon as it gets dark enough I hit the iso/max exposure limit and images are getting underexposed. that is what i am looking for.
oh, i renamed the csv file to doc, because i got a flag stating i could not upload a log.
sorry, most logs of the past days were already gone, but i can make a new one if this one is not helpful.
I only have a lot of UI logs from a project i'm running.
night restart frame 8-9: from 0.6 to 1/3..if i would have let it run, it would have settled at the same 0.6 after some frames, but that setting didn't do it. so i stopped it after 2 frames. (last is with my hand in front of lens)
the other breaks have more time inbetween, so might be influenced a bit by changing light.

i have attached a new log now, so i can show what i mean properly. I stop the script by pressing the shutter(the only way on the m10), so that's why there are missing images in the log

rawopint.doc

12.67KB

c_joerg

I understand your problem. The fist picture is around 1EV underexposed. Meter96 starts with -96 (-EV). A neutral picture should have around 0.
Have you tried to start the script in M Mode? Default Script setting?
The same thing happens on your other cams?

Mlapse

most my camera's are limited to auto or P..only the s95 has an M setting, the m10 has no M setting, but a seperate Tv and Av function.

default script setting on all models i have results in this behaviour, camera's with smaller sensors have it a bit worse though
that subsides once the camera is running a while.
if you want i can run the same thing again with default settings on an a490 tomorrow.

the only constant in my tries might have been the fixed iso

srsa_4c

Mlapse
the m10 has no M setting, but a seperate Tv and Av function.

Mine does, it's on the same (menu) page as Av and Tv. Check again.

Mlapse

you're right, sorry, looked over that. will test the same set tomorrow in M

c_joerg

Just tried it with my M3, see the same think, never notice this beforeâ€¦
Canâ€™t see it in some older runsâ€¦
I have also problems with upload csv files with worked in the pastâ€¦

rawopint.doc

2.25KB

Mlapse

I have also problems with upload csv files with worked in the pastâ€¦

ah, but an image says more than a thousand words. you did one run, so no restart. 5 frames, looks the same to me too. if you would have restarted that whole floating away proces would happen again.
setting: M, same script settings as last csv
so i did 4 runs 2 with night shots (restarted at 26), then 2 in a cabinet with a light. (some 75 in total..guess where i restarted) i hope the slight variance in the "flat" period is due to 50hz lightsource..but can't be sure.

reyalp

Mlapse
Or am I chasing an impossible thing here, because the whole metering concept is different?

There will probably always be some difference.

Have you tried the "Use initial Ev as target" option? This should make the script try to keep the overall brightness of the scene similar to the first shot. There will still likely be some variation, but in scenes that aren't too extreme (e.g lots of under/over exposure, or big variation across the scene) it should be pretty close.

Edit: If you use BV/Ev shift with this setting, it should probably be set to "First"

Regarding posting CSVs, forum settings were changed a while back to only allow whitelisted extensions. I've asked acseven to add .csv.

Mlapse

i tried bv/ev set at first and/or initial ev as target, but it did not help with this.

There will probably always be some difference.

it took me a bit longer, but i suppose you are right.
thanks for the help, could have been mucking with settings for days.

c_joerg

reyalp
Have you tried the "Use initial Ev as target" option?

I always used this as default â€œfalseâ€.

reyalp
This should make the script try to keep the overall brightness of the scene similar to the first shot.
There will still likely be some variation,

I never notice a big variation between a pre-shot and the first image with rawopint.
I made just a test with G1x and M3 with a gray image.
The pre-shot and the first image with rawopint have the same exposure, so no differences even with â€œUse_initial_Ev_as_targetâ€ = false.

But on M3 meter96 is around -96 and on G1x around 0. On the M3 the script increase now exposure to bring meter96 to 0.
If I watch the Histograms in Lightroom, the Histogram from G1x is always around the center. On M3 the Histogram of the first picture is in the center and on the last picture more to the right.
If I do an auto exposure in Lightroom, then Lightroom sets the exposure to around -1EV for the last image.

I thing, the neutral value on the M3 is around on step to high (may be also on M10).That makes the pictures 1 step higher exposed.

reyalp
Regarding posting CSVs, forum settings were changed a while back to only allow whitelisted extensions. I've asked acseven to add .csv.

I would be very grateful for thatâ€¦

rawopint_test_g1x_m3.doc

6.59KB

Mlapse

i noticed this behaviour first time on my s95, and i also have this with my a480 and a490. so it is not limited to the m series alone.
and it depends on light conditions how obvious it is, if i do a night shoot that is very or a bit more than very underexposed you can hardly tell that it gets brighter during the first few shots. for me it is most visible with clouded days and not overly sunny days.

c_joerg

Mlapse
i noticed this behaviour first time on my s95, and i also have this with my a480 and a490. so it is not limited to the m series alone.

On my S110 itâ€™s a little bit different. If I do a pre-shot in AV (I only use AV) then the exposure is around 1/2EV higher. That can be seen on the histogram which is a little bit right. The script brings the histogram exact to the middle. This is different to what I descript in Reply #94.

But on all my cams: if I do a pre-shot in AV, the first picture with rawopint has the same exposure as the pre-shot. Then the script changes exposure.
You should run the script in AV mode. Then I would change the exposure correction in the Canon Menu.

Mlapseand it depends on light conditions how obvious it is, if i do a night shoot that is very or a bit more than very underexposed you can hardly tell that it gets brighter during the first few shots.

Of course, if you set underexposure or overexposure control, the script has to change it to your settings.

Mlapse

Of course, if you set underexposure or overexposure control, the script has to change it to your settings.

that is not what i wanted to point out, it still corrects itself. it is just less visible because it stayes fairly dark.
you can see that on the jpg a few posts back, if there is underexposure correction takes 4-5 frames. at proper exposure that correction takes 9-10 frames

reyalp

Mlapse
I stop the script by pressing the shutter(the only way on the m10)

You should be able to use MENU to stop the script gracefully. The M10 has a menu key, so if this doesn't work, there's a bug somewhere.

edit:
csv upload should be fixed.

Mlapse

You should be able to use MENU to stop the script gracefully. The M10 has a menu key, so if this doesn't work, there's a bug somewhere.

after some testing, it does work, with ultimate if i press the menu key it can take up to a few seonds before it's processed, with rawopint it seems to only respond just after a shot has been made.

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