Tag Archives: focus

What’s wrong with my viewfinder, my old camera had a much better viewfinder!

This is something that keeps popping up all over the place and it’s not just one camera that attracts this comment. Many do, from the FS5 to the FS7 to the F55, plus cameras from other manufacturers too.
One common factor is that very often this relates to the newer super35mm cameras. Cameras designed to give a more rounded, film like look, often cameras with 4K or higher resolution sensors.
I think many people perceive there is an issue with their viewfinder because they come to these new high resolution, more rounded and film like cameras  from traditional television centric camcorders that use detail correction, coring and aperture correction to boost the image sharpness.
SD and even HD television broadcasting relies heavily on image sharpening so that viewers perceive a crisp, sharp image at any viewing distance and with any screen size (although on really big screens this can really ruin the image).
This works by enhancing and boosting the contrast around edges. This is standard practice on all normal HD and SD broadcast cameras. Especially camera that use a 3 chip design with a prism as the prism will often reduce the images edge contrast.
As most people will prefer a very slightly sharpened HD image or a heavily sharpened SD image over an unsharpened one, it’s sharpened by default. This means that the images those cameras produce will tend to look sharp even on screens that have a lower resolution than that of the camera because the edges remain high contrast even when the viewing resolution is reduced and as a result look sharp.
Most current manufacturer supplied LCD EVF’s run at 1/4″ HD with 940 x 560 pixels (each pixel made up of an RGB 3 dot matrix). In addition many of the 3rd party VF’s such as the very popular Alphatron are the same because they all use the same mass produced, relatively low cost panels – panels that are also used for mobile phones and many other devices. 
 
The problem then is that when you move to a camera that doesn’t add any image sharpening, if you view the cameras image on a lower resolution screen the image looks soft because — it is. There is no detail correction to compensate. Incidentally this is why often these same cameras can look a bit soft in HD and very soft in SD compared to other traditional or detail corrected cameras. But, that slightly softer, less processed look helps contribute to their more film like look. This softness and lack of sharpening/processing is particularly noticeable if you use the focus mag function as you are then looking at an enlarged but completely un-sharpened image.
 
It could be argued that the viewfinder should sharpen the image to compensate. Some of the more expensive viewfinders can do this using their own sharpening processes. But the image that you are then seeing is not the picture that is being recorded and this isn’t always ideal. If it is over done then it can make the entire image look sharp even when it isn’t fully in focus. Really you want to be looking at exactly the image that the camera is recording so that you can spot any potential problems. But that then makes focussing tricky.
 
There are a few 3rd party viewfinders such as the Gratical that have higher resolutions. The Gratical and Eye have screens that are 1280×1024, but in normal use you only use 1280×720 for the image area. This certainly helps, but even the 1:1 pixel zoom on these can look soft and blurry as you loose the viewfinders peaking function when you crop in.
 
Sony’s Venice and the F55/F5 can use Sony’s new DVF-EL200 OLED viewfinder. This costs around £4.5K ($6K) and has a 1920×1080 screen. It’s a beautiful image, but even this needs a fairly good dose of peaking to artificially sharpen the image to be able to see that last critical bit of focus. Again when you zoom in the image looks soft and a bit blurry (even on a Venice) as the camera itself is not adding any sharpening. The peaking function on the DVF-EL200 is quite sophisticated as it only enhances the highest frequency parts of the image, so only sharp edges and fine details are boosted.
 
Go back to the days of black and white tube viewfinders and these used tons of peaking to make them useable. Traditional SD and HD cameras add sharpening to their pictures, but most of our modern large sensor 4K camera do not and as a result often the viewfinder images appear soft compared to what we used to see on older cameras or still see today on cameras that do sharpen the pictures.
 
All of this makes it hard to nail your focus, especially if shooting 4K. Even with a DVF-EL200 on a Venice I struggle at times and rely heavily on image mag (which is still difficult) or better still a much larger monitor with a good sun shade and if necessary some reading glasses to allow you to focus on it up close.

So before you get too critical of your viewfinders performance do also consider all of the above. Try to see how another similar viewfinder looks on your camera (for example an Alphatron on an FS7). Perhaps try a higher resolution viewfinder such as a Gratical, but don’t expect miracles from a small, relatively low resolution screen on a modern digital cinema camera. This really is one of those areas where you can’t beat a big, high resolution screen.

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Alphatron ProPull mini follow focus.

IMG_1720-300x225 Alphatron ProPull mini follow focus.
Alphatron MiniPull follow focus.

Over the years I’ve used many different follow focus units. Some better than others, but the majority of them a similar size. I recently got one of the new compact Alphatron Pro-Pull follow focusses to play with. The first and most obvious thing about the Pro-Pull is it’s size. It is very compact. At first I thought this might be an issue as the smaller knob requires more effort to turn than a more conventional larger knob, but in reality it’s not a problem. If you need more torque you can use either a whip or slot in hand grip.

IMG_1724-300x225 Alphatron ProPull mini follow focus.
MiniPull on an F5 working with a Samyang/Rokinon Cine lens.

The Mini-Pull has some really cool features. For a start you can reverse the focus direction by swapping the gear drive from one side of the unit to the other. But the one I really like is the adjustable, locking end stops. This makes it really easy to pull focus from one distance to another. You simply set the stops at your near and far focus positions and then turn the focus wheel between the two stops. If you then need to focus beyond the end stops you simply flip up the latching stop pin and you can focus beyond the end stops. Want to return back to the end stops then simply flip the stop pin back down again. Very clever, very simple and very effective.

The focus marking ring is magnetic so if you need to change or replace this it pulls off easily, yet is very secure when in place. The MiniPull is attached using a simple bracket that attaches to a single 15mm rail. This makes it very easy to adjust the MiniPulls position if your changing lenses and going between different sized lenses. This bracket also makes the MiniPull very compact, which for me as a very frequent traveller is a real bonus.

I used the MiniPull extensively on my recent shoot for the short film “Inviolate” to easily execute a large number of focus pulls. I rate it very highly if you need a compact and easy to use follow focus. It’s supplied with everything you need to get going including a nice flexible lens gear ring and the screw driver needed to attach it. Also included as well as the 0.8 pitch gear drive is a drive wheel with a rubber edge that can be used with lenses without a pitch gear.

Using DSLR lenses on 3D rigs.

Just a quick note on a rather obscure subject. I do a lot of 3D work. Buying pairs of PL mount lenses for my F3’s is beyond my budget right now, so I hire in lenses when I need them. However for my own projects I use DSLR lenses, mainly Nikkors and Tokina’s. One thing that i have discovered is that many of the older manual Nikkors have a tendency to shift the image left and right when you focus. This then miss-aligns the rig. The more modern internal focussing lenses are much, much better in this respect with little or no shift at all. The only problem with the more modern IF lenses is that they often don’t have iris rings (so iris is adjusted with a MTF adapter) and the focus control often has a slipping clutch making repeatable focussing a little harder. So neither is perfect. For 3D applications I think the more modern IF lenses are preferable.

Today3D Electronic Follow Focus and 3D Rig Controller. FIZ

IMG_06621-e1308775858912-300x223 Today3D Electronic Follow Focus and 3D Rig Controller. FIZ
Today 3D FIZ Controller

Here’s a very exciting new product I was first given a sneak preview of at Cinegear in LA a couple of weeks ago, but now I have had a slightly longer look and a chance to take some pictures at Broadcast Asia. It comes from a new name to the market, Korean based Today 3D, but don’t let that worry you, I know some of the guys behind this and they know what they are doing. In addition many of the products coming out of Korea in recent years have been very good, like the NextoDI range of media backup devices. The device is a full wireless electronic follow focus designed primarily for 3D applications. There will be different models capable of driving up to 8 motors for full stereo focus, zoom, iris, interaxial and convergence control down to an entry level 2D wireless follow focus.

IMG_06641-e1308776962962-300x223 Today3D Electronic Follow Focus and 3D Rig Controller. FIZ
Today3D controller screen

The hand controller is beautifully well built, machined out of a solid block of alloy and it feels reassuringly solid, if just a little heavy in your hand. On the right side there is a nice big, silky smooth focus control that sits nicely in your hand. On the face of the controller there is a slide control that would normally be used for the other functions such as convergence or most commonly interaxial. The unit is full programmable via a small joystick and menu system with a multicolour display giving you information about your focus distance, zoom position and interaxial etc. It runs off rechargeable Canon DSLR batteries which easy enough to get hold of wherever you may be. The final price has yet to be announced but I have been reassured that it will be extremely competitive, probably a lot less than a comparable C-Motion controller. It won’t initially come with motors but it has the industry standard motor interface so can be used with motors from Heden, Preston, M-One etc. It’s a great looking piece of kit that really feels built to last. I’m hoping to get hold of one for a full review and test drive in the near future. There are also some other interesting 3D products coming from Korea including some innovative transparent alignment charts! Watch this space.