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Topics - Joachim Buambeki

#1
Hey guys,

I am asking myself if I can get 360° (or very close) shutter with full res silent pictures and intervals of around .5sec. to capture true continuous motion.
Is there a significant processing (down) time between the shots or is it possible to achieve this? Given I use a card fast enough, data rates will not be the issue, right?
Rolling shutter should not be an issue with such shutter speeds, or am I mistaken?

I would like to go full frame and have my eyes set to a 5D2 (preferably) or 6D but I am open to other suggestions in a similar price range as well if said cameras arent't suitable for this task.
Why would you pick the 6D over the 5D2 and vice versa? I assume the 5D2 has faster write speeds with its CF cards despite the 6D having the better sensor overall.


Looking forward to your replies and suggestions! TIA :)

Cheers
JB
#2
Hi,

for flicker-free timelapse one has to shoot either wide open or has to press the DOF preview button and then unlock the lens to keep the aperture locked.
If shooting a timelapse without the above, the aperture will close and open with each image, this leads to flicker because the aperture is not 100% accurate (which is not relevant or visible for photography - I am talking about ~0.05EV).

Is there a way to keep the aperture locked while shooting timelapse?

Thanks for listening!

PS: Great new place this is. :)
#3
Hi,

is Auto-ISO still on the list of future features of ML?

Here is my idea how it could work:

It is pretty simple actually (probably not that easy is to implement though...).
The idea is to always get the lowest possible ISO while having shutter speeds that ensure that your image is sharp when shooting handheld.

Example:
I am shooting in a theater with changing lighting conditions in AV mode at f/2.8 Its bright I and my metering gives me 1/160 sec @ ISO 800 which is perfect for a sharp image. Then the light changes and I get a metering of 1/20s which is too slow for a sharp image. I have to bump the ISO which is pretty annoying if you have to do it all the time. Of course you could just keep your ISO always at 3200 but that won't get you the best possible image quality in terms of noise.


The Auto ISO mode I have in mind would work like that:

1. define max ISO (never exceed ISO 3200 for example) even if that means disobeying the 1/(focal length in mm) rule
1.1 additionally defining a min ISO (like 200) to get less motion blur if the lighting conditions allow it is a good idea.
2. get correct focal length from the lens ID (important to get the current focal length for zoom lenses!)
2.1 if the former is not possible or you are using a manual lens, have an option to set the focal length by hand
3. Have a multiplier (+ and - in stops) that can be selected by the user for the 1/(focal length in mm[*1.6 for crop cameras]) rule because the lens has an IS or you're a bit shaky and can't handhold those shots properly.

The the ML firmware then meters the shot and chooses the ISO as low as possible to still get 1/(focal length in mm)*IS multiplier(or divider if you're shaky).

You don't have to detect if the lens has an IS in the ML firmware, just set the divider to the value you think is right and you're good.


AFAIK the 1D series has that feature build in (except for the multiplier for the IS).

Thanks for listening. :)
#4
Hi,

I have already discussed this with Alex a while ago and he thought it it was unncessary, but I still think it is a worthwile addition to the repertoire of a timelapse shooter to have finer control over the intervalometer than the 1 second steps we have right now.
I hope this open thread will help to convince Alex by having others supporting the idea. :)

When shooting fog, or fast moving clouds streaming across a mountain top you usually choose 1-2secs so the possibility to fine tune that would be extremely useful. Going from 1sec to 2 sec means that the clouds move twice as fast which is not really ideal when 1sec is just a tad too slow for the final product.
Trust me there is use for this - people actually pay good money for a device dedicated just for that:
http://pclix.com/   (you may also read this: http://tech.groups.yahoo.com/group/PanoToolsNG/message/50622)

My proposal for an advanced intervalometer would be something like this:
.4 , .5, .6, .7, .9, 1, 1.2, 1.4, 1.7, 2, 2.5, 3, 3.5, 4, 5, 6, 7, ....

The extreme fine granularity at the lowest intervals is important because each camera has a different max continous RAW speed that has to be determined, at least for the 5D2 JPEG you can shoot with full speed (3.8fps) continously AFAIK.

I know this a bit more to click trough for those who don't need it, but for those who need it makes a world of a difference. Perhaps it can be disabled for those who can't be bothered.

(Please don't advise to speed up in post, as the results can never be as good as a proper interval, especially when shooting clouds or any kind of water where twixtor or whatever you use will just produce unreliable or bad vectors)


AEB is something else that needs finer granularity for timelapse purposes.
With my 5D2 the finale HDR detoriorates too much somewhere around 3EV spacing. Since it is highly impractical to shoot 5 or 6 images per bracket it would be good to just cover the needed dynamic range with as little pictures as possible.
Sometimes 3x3EV just isn't enough, but 3x4EV gives a only mediocre HDR, so something in between would be nice to get just that extra stop that is necessary to cover the dynamic range.
Again, this isn't particularly useful for still photographers, but for timelapse shooters.

Thanks for listening! :)