Choosing follow focus gear rings

Canon 5D Mark II w/Fotga DP500 II follow focus and generic 60-70mm fixed diameter ring

The cinemazation of DSLR cameras have created a need to add 0.8 pitch follow focus gears to standard photography lenses. Many such gears exist on the market; however, not all are created equal - a fact that is not immediately apparent until you've already experimented with a few.

The prevalent types of follow focus gears available to the prosumer cinematrographer today come in three different variants:

• Left: Plastic, adjustable diameter gear ring with friction lock and lever
• Center: Rubberized, adjustable diameter gear ring with tooth lock
• Right: Fixed outside-diameter ring w/10mm variable inner gear ring diameter (various sizes available), made by Cinematics and others

I've used all three in the field - following are my thoughts on each:

Semi-hard plastic, adjustable gear ring with lever

The adjustable plastic gear ring is my least favorite in that the toothed reverse of the plastic isn't that grippy. I've yet to have it slip, but it does not inspire confidence. Likewise, the lever locking mechanism of the lever is cheap, damages the gear teeth, and the lever gets in the way of follow focus units unless oriented to the opposite side of the rig.

On the other hand, the plastic gear teeth engage well with follow focus units, and it is especially handy when using an older, manual telephoto prime for focus control.

 

Rubberized adjustable gear ring

The rubberized gear rings can are soft enough to grip a lens - and grip well - but this also causes the teeth to flex while meshing. The toothed receiver also works well to keep the ring tight.

Unfortunately, coupled with small-diameter lenses and a follow focus mounted in certain places, these rings will jump teeth - and visibly so on screen. Nevertheless, they are effective on larger-diameter lens barrels.

Cinematics 80-90mm at left, generic 60-70mm at left

These fixed-diameter rings are my personal favorites, having the ability to reach a follow focus unit with ease, regardless of lens barrel diameter. This style of gear ring is presently available as a generic (only one at present, it seems) and by Cinematics with slight differences between each. Both companies produce inner diameters ranging from 60-70mm up to 108-116mm. In my experience, the generics have enough adjustment to fit barrels down to 57mm comfortably; possibly smaller.

The generic's plastic-knob bolt is durable, despite its cheap appearance.

Cinematics' units have a smoother finish than the generics and have an allen head bolt with a proper steel nut, but otherwise show no superiority over the generics in operation or durability. Unlike the generics, they are available in red and blue (I've also seen purple) as well, which is fine if you're a hipster who must color-coordinate your camera rig to your fixed-gear bicycle and Macbook. Personally, I see no point to it - why call more attention to an L-series lens by putting red gear rings on it?

Additionally, a pair of these rings can provide both focus control and a precise zoom control for lenses with fixed zoom rings - such as Canon's L-series. Given the lack of perfect video-quality fluidity in even the L-series lenses - not to mention the fact that most photography lenses are varifocal - controlling zoom through a second gear ring and follow focus unit can be a stress-free method of ensuring a perfect take on the first try.

-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.

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.

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.

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.

Lens sharpness does matter, Mr. Ken Rockwell.

Warning: This is a controlled rant alert.

When I first started with a DSLR, one of the first websites I found was Ken Rockwell's lens reviews. Chances are, you've seen his site too - seeing as they rank highly on Google - and he's pretty darn good.

Nevertheless, there is one article on his site that I beg to differ with: Lens Sharpness Doesn't Matter.

Well, Ken - sorry to disagree with you, but sharpness does matter. Sure, lens sharpness may be overrated - especially when comparing some of Canon's mid-range zoom lenses to L series offerings with shockingly similar performance - but it is a topic worthy of some finesse.

Thing is, sharpness is not an all-inclusive definition of a lens. Sure, a lens may be sharp in its center, but that may be the only place it can claim that fame.

Two, older EF-mount lenses prove that point:

Canon 22-55mm f/4-5.6 USM

Tamron AF Aspherical 28-200mm f/3.8-5.6, EF mount

Though both of these lenses are no longer on the market, they're generally quite affordable on eBay - making them appear to be quite attractive to the DSLR filmmaker looking for a dirt-cheap starter lens.

Sucker alert.

If lens sharpness did not matter before, these two lenses ought to change the course of things. There's a certain manner that both of these lenses handled areas out of focus and those areas supposed to be in focus that the line became quite blurred (pun not intended) between what was what.

That, and vignetting (darkening of the edges) occasionally proved to be an issue as well.

Cases in point - from the Tamron:

It's not that this photo isn't sharp (though there is enough purple fringing on all the edges to make it appear as if the camera was shaking slightly during the exposure), but the sharp areas and blurry areas all look about the same.

Technically speaking, the difference between these areas are known as the "circle of confusion" (explained very well here: http://www.cambridgeincolour.com/tutorials/depth-of-field.htm), but - for the purposes of this basic explanation - let us just call it for what we see in the photo: It is a circular, muddy mess, with vignetting to boot.

Mind you, this is a photograph taken in RAW, not video or .JPG, so you can imagine what the results would have looked like with the extra compression (or reduced scan lines as the 5DM2 uses for 1080P). Not so good.

The Canon didn't fare much better:

Aside from obvious fringing, the out-of-focus areas in harsh sunlight look as if the camera was mounted to a pogo stick. Granted, I could have put a gradual ND filter on it for these photos, but I doubt if I would have improved anything other than the exposure.

It's neither sharp, nor pretty - it's muddy.

In closing, lens sharpness does matter, though the overall sharpness of an image is more a result of whether the lens does a nice job of separating the out-of-focus areas from those that are in focus.

Be mindful of what you're buying, and remember this when you find a low-end lens for cheap:

"In the field, bad lenses are worth half of what you paid for them."

-Kurt K. - "Man with the 5D"