CMOS Rolling Shutter Removal - Plugin Shootout!

I'm getting away with whip pans like these.

Or just about, anyway.

That said, I'm not going to bore you with an explanation of what rolling shutter is. Chances are that - before you reached this blog - you already went through the torture of a few hundred posts and videos of everyone else demonstrating rolling shutter - without the slightest suggestion of a good CMOS skew and jello removal tool.

You can relax now, for I'm going to show you a comparison between the five filters that are available for doing just that, and the most professional one of the lot.

Better yet, the best one isn't even the most expensive.

Following is our list of candidates:

1. The DeShaker plugin for VirtualDub:
• Free; requires that you convert your footage to AVI before importing. 
2. Adobe's After Effects' Warp Stabilizer, available since CS5.5:
• Requires purchase of one of the Adobe suites. Not necessarily cheap.
• Note: CS6 is equipped with a dedicated rolling shutter corrector, but I did not have time to download CS6 to try it.
3. ProDAD's Mercalli PRO Version 2
• $249 from the ProDAD website
• Sony Vegas - since version 10 - contains a simplified version of Mercalli; we'll cover only the standalone.
4. New Blue FX's Video Essentials III plugin, which contains a rolling shutter removal tool.
• Works with Adobe After Effects, AVID Media Composer, and Sony Vegas, amongst others. $130, plus the cost of your editor.
5. The Foundry's Rollingshutter plugin for Nuke and After Effects
• A cool $500.

Do note that I'm taking this from the point of view of PC's, though MAC users have a rolling shutter removal tool in Apple's Final Cut 10, and the Foundry's plugin is also MAC compatible.

Seeing as there is no better way to see the results than a video, I prepared three rolling shutter examples and ran them through each of the five filters:

 

Though not covered in the video, program usability presents a concern as well; after all, a timely workflow is essential to smooth editing.

Conclusions:

• DeShaker is an absolute nightmare to use. Besides having to convert footage to AVI (I used Pazera MOV to AVI to do so - it was quicker than Adobe Media Encoder) before even importing it, setting the plugin up in VirtualDub is a hassle, and it takes ages to analyze the footage. You'll wind up with some pretty big AVI files to clean off your drive too unless you install and compress with the x264vfw plugin.
• Warp Stabilizer, along with the New Blue FX and Foundry plugins run the same as most other effect plugins for After Effects. New Blue FX had a tendency of crashing AE at times, while The Foundry's plugin can become a long and drawn-out process.
• Mercalli is ridiculously fast, and arguably the most user intuitive. It almost looks too simplistic and mainstream to be a professional tool, but - as proven by the footage tests - it is superior to everything else as a general-purpose tool. 
• At best, the only further improvement would be to correct individual extreme skew issues with New Blue FX before importing into Mercalli. With certain footage, this workflow could remove rolling shutter skew entirely.

One last option remains for CMOS skew removal (exclusively - this method will not correct for jello/jitter), if you do not mind a bit of DIY: Layer seven or eight feathered copies of the problematic footage over each other, with each successive clip (from top to bottom) playing progressively slower than the first - thereby correcting for the top-to-bottom scan delay in most CMOS sensors.

Mike Huetz on Vimeo has a brilliant video tutorial of this method: http://vimeo.com/10130633

Regardless, a powerful filter does not negate that one can ignore CMOS rolling shutter when shooting, expecting that you can fix everything in post. That's not a reasonable though - you simply cannot walk into a shoot and expect to get away with it.

If absolute perfection is what you need, the Black Magic Production Camera 4K - with global shutter - should be your next purchase, rather than a rolling shutter corrector.

In fact, I fully intend to become the Man with the BMPC 4K someday, but that's the future.

Where did I leave my DeLorean?

No monetary compensation was provided for the mention of any of the products listed. All were tested during product trial periods or were purchased by myself.

Filters Continued: Polarizers and ND's for video

Today's post comes in video form:

For those curious, most of these tutorial videos are shot with the Canon EOS-M in addition to my 5D Mark II.

I generally run the EOS-M with the Compact Macro EF 50mm that I featured on the 9th:
Compact Macros & DSLR filmmaking

Enjoy.

-Kurt "Man with the 5D"

Graduated ND filters for bright skies

If you've ever shot a video with a bright sky in the top of your shot and dark foliage below, you've undoubtedly experienced the problems of exposing an image for such a situation - and it usually winds up with your clouds blown out to bright white in order not to underexpose the rest.

Since it is difficult - and often impossible - to post-process multiple exposures with video (as is sometimes done in photography), bracketing techniques are not an option.

For this reason, you might have already dug up these little critters - graduated grey ND filters which screw onto the front of your lens and gradually shut out light where you don't want it:

Unmarked 52mm on the left, KOF Concept 72mm on the right.

Unfortunately, they don't work. Not well, anyway.

Why?

1.
The location of your gradient is fixed. You can rotate the filter 360 degrees on the front of your lens, but that won't help you much when your horizon line isn't in the upper-third of your frame.



2.
The amount of reduction is minimal. Normally, a non-graduated ND filter is marked by the number of f/stops it reduces exposure, e.g.: ND2, ND4, ND8, etc. The two examples above are not marked with anything (nor are they sold as having any particular reduction), so the amount of ND reduction you're getting is unknown. Tiffen's graduated ND filters are sold as ND0.6, so we'll assume the 52mm Chinese knockoff is a copy of the same.

As there is nothing better to illustrate this than an example, following are a pair of comparison shots, taken at the same exposure:

Without 52mm graduated grey ND0.6 filter

With 52mm graduated grey ND0.6 filter

The filter does help, but I could have used at least another stop of reduction (if not close to two, if the palm trees at the left were not present). My experimentation with the 72mm KOF Concept filter did show much of a performance difference to the generic 52mm.

 
3. 
You can't use these with step-up adapters, because of problem #1 - the fixed gradient. If you were to put the 72mm filter on a 52mm lens (shown at right), the 52mm lens will only see a small portion of the gradient - not enough to make a difference.




This is where the alternative steps in - Cokin P-style, slide-in, graduated ND filters:

Given that the design allows one to put the gradient wherever they please (and vary the amount of reduction depending on the ND glass used - my set came with ND2, 4 and 8), it is considerably more versatile than the screw-on type (and it isn't affected by step-up rings).

Following are the results of a few minutes of experimentation with the graduated ND8, all shots taken at ISO 125, 1/320 shutter, with my Nikon 50mm (with a 52mm thread stepped up to meet the adapter's 72mm threads) at f/4:

No filter

Filter approximately centered in the holder

Filter level with top of filter holder

I'd say the centered ND8 is about as even an exposure one could ask for before going to color grading. Definitely better than the results from the thread-on filter.

-Kurt "Man with the 5D"

No monetary compensation was provided for the mention of the any of the products mentioned or shown in this article.

Aperture Flicker: Why you should have a manual aperture zoom lens...

...and why electronic, variable aperture zoom lenses are a poor choice for DSLR filmmaking:

Aperture flicker is a phenomenon of zoom lenses with variable apertures at the open end. For the purposes of this explanation, let us consider the following Canon EF 28-135mm zoom lens - it will run open as low as f/3.5 when at 28mm, but will close to f/5.6 when the focal length increases to 135mm.

As the lens has an electrically controlled aperture built into the body, the lens will automatically stop down from f/3.5 to f/5.6 when zooming, causing an abrupt reduction in light as the iris is closed in individual clicks/stops.

It is the same look you'd get if you operated the iris/aperture of a manual lens that had not been de-clicked for film/cine use.

Now, at this point, you're probably saying: "Wait - what if I simply stopped down to f/5.6 for the entire shot? That makes perfect sense, doesn't it?" It certainly does, and you'd be dead wrong, despite what many DSLR photographers (as opposed to videographers) would like you to believe.

In short:  

Even if you stop down to an f-stop that works across the entire focal length of the zoom lens, IN MANUAL MODE, the electric aperture will flicker anyway.

The problem lies in the hard-coded programming of DSLR cameras, which checks at each of the critical stop-down points in the focal range to see if the aperture needs to be stopped down when you zoom, activating the iris mechanism for a split second, thereby causing the momentary darkening of the image. It will do so even if you already stopped down the lens to prevent the system from stopping it down for you.

That's right - so long as you have an variable aperture zoom lens with electronic iris/aperture control (more or less a Canon EOS and M43 issue), you cannot use the zoom on your lens without getting completely uneven light. 

For those of you who want to see this as a video, following is a direct comparison of an all-electronic Canon EF 28-135mm zoom lens  - with a variable f/3.5-5.6 max aperture - against a 1980's Tamron 28-70mm zoom. Just to make the comparison more stark, the Tamron is also a variable maximum aperture lens (f/3.5-4.5, specifically), but it adjusts mechanically - and therefore does not distract from the image.

 

Obviously, aperture flicker is not a problem for still photography, but it proves to be a severe issue for videos.
 
DSLR filmmakers are left with three options to get around aperture flicker:

1. Use zoom lenses made for your existing mount that will run a constant open f-stop across the entire focal range
• Some common zoom lenses are manufactured as described (the EF-mount Canon 24-70mm f/2.8 L - both the original and the II - and Panasonic's 35-100mm f/2.8 for M43 come to mind), but this may needlessly restrict your lens options.
• Note that if you are shooting telephoto-length lenses, using a modern, constant aperture lens is your ONLY option, due to the requirement of image stabilization and a fixed zoom ring. Admittedly, this solution is pricy, I cannot think of a better excuse to justify a 70-200mm Canon f/2.8 L IS to your significant other.
2. Use a lens made for your existing mount that has manual iris control.
• To my knowledge - short of Cinematics' customized (and pricey) cine lenses - non-existent at the prosumer level. Rokinon/Samyang's budget cinema lenses for EF mount are all primes, as are Noktor's SLR Magic series for Micro 4/3.
3. Use an older manual zoom lens with an adapter, preferably de-clicked.

Redrock Micro's LiveLens MFT

But there is a fourth way too:

Granted, this option only exists for M43 users who wish to use EF-mount lenses, but it is an option at any rate: Redrock Micro's M43-to-EF LiveLens MFT, shown at right.

Upon request, Redrock was kind enough to report that the LiveLens controller does not cause aperture flicker when used with a variable aperture lens. Specifically, the LiveLens was tested with a Canon 20-35mm f/3.5-4.5; when set at at f/8, the lens exhibited no aperture flicker when zoomed and retracted.

One last note: Obviously, photographers don't need to worry about this problem, but it hasn't prevented a number of discussions about aperture flicker to appear on photography forums. Be forewarned that a good deal of the advice written on these forums - though well-meaning - are often misleading, or do not apply to DSLR filmmaking.

Kurt K. - "Man With the 5D" 

No monetary compensation was provided for the mention of the LiveLens MFT for this article. LiveLens MFT image and data was provided by Redrock Micro upon my request.

Mounting Nikon lenses on the Canon 5D Mark II, EOS, M43 and others

Amongst the trends of DSLR videomakers is to mount older, manual Nikon/Nikkor F-mount lenses (amongst others) to the front of their Canon EOS cameras.

It is a good trend; one that keeps you from the aperture flicker nightmares described in yesterday's post. These older Nikons are also known for their buttery smooth, long-throw focus rings, as opposed to the ultra-minimal throw of most Canon EF lenses (those that are not outrageously priced, anyway).

Nikon's Series E 50mm f/1.4 (with Nikon-EOS adapter) and Nikkor 28mm f/2.8 - two fantastic lenses.

For the more involved (or determined) user, documentation exists for de-clicking Nikon aperture rings for fluid exposure adjustments too - a more involved task that I won't cover, just yet.

Mounting these Nikon lenses is as simple as an adapter ring off of eBay, and said adapters are not necessarily expensive either. Not all of these adapters are perfect, but the choices are varied (more on that later).


Using Nikon AF lenses:

One thing that was never made clear to me until I tested it myself: Nikon's later AF lenses with autofocus motor contacts will also fit a 5D Mark II (provided the rear glass element clears), as the autofocus contacts do not sit deep enough into the body to contact the shutter:

Using other lens brands:

Adapters are also available for Olympus OM-mount lenses, M42 lenses, amongst many others. A number of these will work, though there are also some combinations which are either incompatible or require modification.

Even Nikon G-series lenses can be used with full (though manual) control of the aperture as well with Fotodiox's Nikon G-to-EOS adapter, which adds an external control to control the iris lever at the back of the lens.

The only caveat to this suggestion - and I'll repeat it as much as the rest of the internet:

Make sure the back element of your lens clears the shutter of the camera.

By that, I don't mean sticking the lens in your camera body, turning it on, and waiting in tense anticipation of whether the shutter will snap upwards or snap into pieces when you hit Liveview. I mean making absolutely sure that this won't happen at all.

Due to a very similar shutter design, some 5D Mark II owners keep a 35mm Canon EOS 650 body ($15-20 on eBay - this is the 35mm EOS 650 SLR I'm speaking of, not the current T4i/650D DSLR) on hand for these tests.

Documentation as to compatible lenses is spotty, but I've tried to assemble a rough guide from my experience and collective information from forums. This chart is by no means complete, but it is a handy, general guide to compatibility:

Mount	Compatibility with Canon EOS and others (Details given are for the 5D Mark II, though this also applies to most EF and EF-S-mount cameras)
Nikon F	Most all, with a few exceptions. Early lenses may have protrusion issues. The 20mm f/4 AI* will not fit without modification, as possibly the 24mm in both f/4 and f/2.8 variants.  *Note that the 20mm f/2.8 AI-S is compatible, as is the later 20mm AF-d (part of the Nikon AF group below) is said to work without issue.
Nikon AF	Most all
Nikon G	Most all - use Fotodiox's Nikon G adapter for aperture control. Full-frame users - beware of DX-series G lenses, which are for crop sensors only.
Olympus OM	Most Zuiko OM lenses will mount; OM-mount Vivitar/Tokinas are usually safe as well. Other aftermarket OM-mount specifications are unknown.
Pentax M42 (screw mount)	Luck of the draw - some may interfere with the shutter, others may work fine. Proceed cautiously. A partial compatibility list is located here. Many inferior adapters are made for this mount - see this forum thread for a comprehensive overview of M42 adapters.
Tamron Adaptall/Adaptall II Adaptall II shown below w/aftermarket EOS adapter	To my knowledge, all Adaptall lenses are compatible when used with the Tamron EOS Adaptall mount. Original EOS mounts are scarce; aftermarket alternatives are available on eBay. Note: Adaptall II 28-70mm CF Macro f/3.5-4.5 will vignette at 28mm when used on full frame EOS with EOS adapter.
Contax RTS, Kalimar (C/Y bayonet) Planar/Sonnar/Tessar/Distagon Kalimar 50mm with C/Y bayonet	Some fit, some will interfere with the shutter. The following Contax models and focal lengths will not fit without shutter interference. Some may fit with modification: (Documented from posts at:   http://forum.mflenses.com/5d-mark-ii-lens-compatibility-chart-t15761,start,150.html) Distagon T*: 15mm f/3.5  18mm f/4  28mm f/2 35mm f/1.4  Tessar T*: 45mm f/2.8 (varies depending on production run) Planar T*: 50mm f/1.4 Mutar II T* 2X extender Lots of good information about the RTS lens range documented at RedUSER.net Note: Some budget-range Kalimar lenses use the Contax/Yashica bayonet mount. Some of these lenses are marked "Y" on the rear to identify the mount.
Contax N	Completely electronic auto-focus design in the fashion of Canon EF. No adapters available; direct modification to lens necessary. Expensive.
Minolta AF / Sony A	Electronic design with camera-controlled, lever aperture (no aperture ring) and a backfocus distance almost identical to EOS, requiring an optical adapter with a manual aperture control ring. Will work with extension tube adapters (no optics) on M43/EF-M.
Leica-R	Some yes, some no. Full list here.
Fujica X, Contax G, Konica F, Leica M, Minolta MD, Miranda Referenced from:  http://www.bobatkins.com/photography/eosfaq/manual_focus_EOS.html http://photonotes.org/articles/eos-manual-lenses/	Backfocus distance (lens to sensor/film) shorter than Canon EOS (44mm). Ineffective if used; causes macro effects. Will work on M43/EF-M bodies due to extension tube adapters.
Canon FD	Same back focus issues as with the lenses above; however, Canon used to sell an optical multiplier to interface with EOS; worked only with select telephoto lenses - a detailed list is here. Usable on M43/EF-M.
Pentax K (PK)	Incompatible on full-frame EF without modification - aperture lever interferes with shutter. Usable on M43/EF-M.

I am open to updating this list with any additional experience that readers may have encountered.

An very comprehensive list is available at the MFLenses forum:
http://forum.mflenses.com/5d-mark-ii-lens-compatibility-chart-t15761.html

M43 / EF-M users:

Regardless of compatibility with the full-frame 5D Mark II, most all of the lenses listed above are adaptable to cameras utilizing the Micro 4/3rds mount*, or Canon's EF-M (specific to the EOS-M at this time).

Panasonic GH-2 shown with M43 adapter (mounted to GH2 body).
Photo by Eduardo Morales - used with permission

The mirrorless design of M43 and EF-M cameras allow the sensor to sit very close to the front of the lens body, thereby allowing for lenses of shorter backfocus distances to be used as intended - with the proper adapter. These adapters are essentially extension tubes due to this design, which also solves the issue of clearing the auto/manual tabs that would otherwise hang up the mirror on a DSLR.

Note that an exception exists in Canon's entirely electronic EF lenses, which do not have a physical lever to operate the iris blades. Though this does not pose a problem with Canon EOS crop-sensor cameras (direct fit), nor the EF-M mount (Canon's EOS to EF-M adapter has pass-through contacts for controlling the lens), M43 cameras cannot inherently control these lenses.

In such cases, the only manner of mounting EOS to M43 - while retaining aperture control - is Redrock Micro's LiveLens MFT, shown here:

Redrock Micro's LiveLens MFT

Adapter quality and thickness:

Some cheap Nikon adapters have had the distinction (or lack of it) to be machined too thin. Though there remain some inferior adapters out there, the culprits are no longer common on eBay - and the difference between the two can be spotted easily.

Just the same, a snug fit is essential - whether you get it from an expensive Cinevate adapter, or something less pricey.

Case in point, the adapter to the left (in the photo below) was packaged in a DLG-brand box. Who actually made it? Anyone's guess, but it is a quality, one-piece CNC stainless steel adapter. My Nikons fit tight on it, with zero rotational shift. $40 at the local camera store, and I can't find any of its kind on eBay for a similar price.

The one on the right is a Chinese generic that came in a white cardboard box. Unlike the DLG, it is chrome plated steel, and will wear over time. Granted, my Nikon AI-series lenses fit equally tight on it (AF lenses not so), though there is about 0.5mm of rotational play in this adapter (which one can shim with adhesive clear acetate). Price was $10 on eBay.


Which one is better? You'll have to choose what takes precedence - the savings of $30, or the assurance of zero rotational play. It all depends on whether you want to trade fit for cost.

Nevertheless, most users seem to like the standard Nikon F-to-EOS Fotodiox adapters, which can be had on Amazon.com at prices just as competitive as any of the off-brands. The difference in price is negligible, and they prevent quite a bit of guesswork and frustration.

A word of warning to the starving artists:

If your plan is to use your camera rig to keep the rent paid by freelancing everything in sight (a.k.a. = "If you are on a budget and have to take the lousy jobs too...") do not let this blog post convince you to buy exactly one, glorious Nikon prime lens to cover every possible situation you may find yourself in.

If this describes you, I still stand by one of the recommendations I made in my Top 5 list - get yourself a cheap Canon EF kit zoom with IS (image stabilization), such as the Canon EF 28-135mm f/3.5-5.6 IS USM, which can be had for $200 used.

Yes, I hear the experts shouting "BLASPHEMY!" and whining about loss of precious image quality from every direction - even I am no fan of this lens either due to sharpness dropoff on the corners, amongst other reasons - but it'll cover a reasonable range without requiring lens swaps.

Granted, if you are lucky enough to have saved up a lens budget in the $700 range, the Canon 24-105 f/4L IS is the best choice you could make of any Canon lens, as the constant aperture and smoother zoom ring gives you the ability to zoom reasonably smoothly while shooting.

Most importantly however, if you get that Freelance Job from Hell that requires you to shoot smooth shoulder-mount footage in the midst of a mob resembling the Pamplona running of the bulls, that precious little IS button just might save your footage from becoming a tribute to The Bourne Ultimatum. Nevertheless, make sure to look into ProDAD's Mercalli Pro for stabilization.

Yes, you can wait for that Nikon lens if you have to.

-Kurt "Man with the 5D"

No monetary compensation was provided for the mention of any of the above products. LiveLens MFT image has been provided by Redrock Micro upon my request.

Counterfeit Canon EOS rear end caps - how to avoid them.

As we all know, there are various easy-to-manufacture Canon bits out there that are counterfeited. Some work, others don't.

Lens caps are amongst the most popular of these ripoffs, though most copies are honest enough to strike the Canon logo from the back end. Nevertheless, there are a few Chinese industrial thieves out there who make copies bearing the Canon logo, the following being one of them:

Given that whoever ripped this off was armed with an AutoCAD designer and at least one injection molding machine, it should perform its function as intended.

<voice="Dom DeLuise_blazingsaddles"> 

WRONG!

</voice>

I wound up with three of these after ordering a set of what was advertised as unmarked blanks on eBay. I received three Canon-badged counterfeits marked "Made in China" on the plastic packaging and the part number D00564.

All three varied drastically in fit on both Canon lenses and the adapters - one wouldn't even fit the adapter - and all three caps fit different when tested on one single lens.

By comparison, two genuine Canon caps (one marked "JAPAN" with a matte inner finish and the other "CANON INC. MADE IN TAIWAN" with a high-gloss inner finish) fit every lens and adapter of mine with no issue, in addition to an unmarked Canon EOS clone cap from eBay seller Digitalgoja (ironically enough, marked "MADE IN CHINA" on the reverse).

L-to-R: Canon (Taiwan), Canon (Japan), Canon-badged counterfeit (China, unmarked), generic (China)

Reverse of the above - same order

That said, there is a slight difference in finish and shape of the counterfeits to the two genuine Canon caps (which differ amongst themselves), as there is between the counterfeit and the unmarked clone. Unfortunately, the multitude of castings make it difficult to identify the clone while juggling an unknown in a store:

Can you spot the fake? I'll give you three guesses.

Probably the easiest way to detect the counterfeit are three ridges that are cast on the inside of the cap:

Convenient garbage indicator.

For the record, the counterfeit caps came from eBay seller Worldokit, who advertises them as unmarked blanks with this photo:

Worldokit - you took my money, so I'll take your photo.

Caveat emptor.

-Kurt "Man with the 5D"