Update – Time Lapse HDRI Skies

I’ve had a very technical week or so and have been unable to shoot much at all due mostly to weather. Even processing images has been slowed by a recent hardware upgrade and a couple of power failures – its been pretty stormy in Adelaide lately!

In a nutshell, I’ve been working on:

• Deflickering. Harder than I thought it’d be – I’m trying LRTimelapse which isn’t exactly made for deflickering without a non moving reference point (moving clouds are a problem). I’ve got a number of After Effects plugins lined up and ready to try.
• Dust! Grrrr! 999x more annoying when working with 1000’s of frames of footage, I’ve just ordered some sensor cleaning stuff after failing to remove it with my existing tools. Pretty sure I have a speck of oil or something on the sensor that wont move. Removing dust in post with moving clouds is also extremely difficult and highly noticeable when things are moving. Again, trying some plugins…
• Colour Calibration. I’m about to order the SpyderCheckr Pro which will allow me (with the gracious help of a film professional) to create colour lookup tables and essentially ensure that I get completely accurate colour, which is important when shot through ND filters that are never 100% neutral. This should also help to create a fully linear image.
• PTStitcherNG issues. NG is the far faster option for de-fishing, however I’m having issues using each bracket to batch create HDRIs in PTGUI, as NG doesn’t create Tiffs with exif data, and PTGUI loses image parameters in the batch builder when new images are loaded in…
• Re-installing everything after an SSD upgrade. Everything now opens really quick and is more responsive, but unfortunately even halving some of these processing times doesn’t make much difference. I’m now considering just getting a dedicated extra machine for rendering so I can continue working with that running at the same time.

F11 for max dynamic range, flickering problems, detaching the lens

If I can’t solve the deflickering issue with software, I have one option left which seems rather extreme, and that’s to actually disconnect the lens from the camera, which forces the aperture to stay at f11, no longer open/close, and therefore stay at the same opened position and no longer flicker. This could save me in post as well even if I can find a good solution – so it might be worth doing regardless. I believe the options for disconnection can involve some hardware add-ons for the lens, or you can try a cheaper solution which is to sticky tape over the lens connections so the camera can’t communicate with the lens(!)

Colour calibration

Before I go a lot further with the next round of time lapses, I thought it’d be wise to first ensure I’m getting the most accurate colours possible. A friend of mine is going to help me create colour lookup tables in Nuke that hopefully I can load into Lightroom or Photoshop and correct for the ND filter. While my Wratten2 filter may be slightly superior to the one Debevec used (?), if it allows more red light in, then that’s going to be desaturating my blues (sky colour!) which isn’t great, so I think this is pretty essential.

Next steps

I’m going to continue trying some deflickering solutions, but unless I come across a really perfect solution, I’ll likely detach the lens somehow to force that aperture to stay exactly the same.

Once I get the SpyderCheckr, I’ll shoot a bunch of calibration shots and then go back and apply that to all the photos I’ve taken. I’ll make some before and after shots where the before shots are desaturated, blurred, covered in dust and scratches, then an after shot… In all seriousness though hopefully it’ll make a nice difference!

Then… I’ll finally be happy to release some samples! Hopefully I can release those alongside a VRay/3ds Max tutorial. Sorry I’ve been so slow getting these out, I just don’t want to give people anything that’s not 100%!

Pretty pictures

Since this was so dry and technical, here’s a preview of a sky I shot the other day in between all the rain. I’ve time-stretched/frame-blended this in After Effects – I love that you can double or triple the length but I guess the obvious drawback is that with EXRs you’d get 40-60 gigs instead of 20 per time lapse! Frame blending a render might be wiser? Try not to look at that lovely dust spot…

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