Lens Image Circle Database

I say database… But it’s really just a list trying to sound official.

So basically, RED has given the world a great deal of technology at a great price. But they also induced many a headache with different sensor sizes, resolutions, specs, and names. To make things a little easier, I’m compiling a list of lenses that pass through the shop and recording their image circle, or the diameter that they will cover without vignetting. This list will simply show you what the lenses are capable of. Feel free to comment on this post if you see any discrepancies or want a specific lens added. I want this to be as accurate as possible. Also note that the sensor/format sizes are generalized. There are a ton of different industry standards. There are several dozen formats that fall under 4 perf 35mm film alone.  Continue reading Lens Image Circle Database

Lens Mod FAQ

I receive dozens of emails everyday and I want to respond to them all but sometimes it just isn’t possible. I’m not a trade secret kind of guy. I like to spread knowledge and educate as many people as I can. So here is a quick little FAQ in regards to lens modification and a few other common questions I am asked… Frequently.

1) What lenses work well for motion picture?

2) I have a bunch of still lenses. Can they be converted to work for cinema?

3) What is a Cine-Mod?

4) Can my lens be Cine-Modded?

5) What lenses are well suited for a Cine-Mod?

6) Can the mount on my lens be changed?

7) I have Nikon lenses. Can the focus be reversed?

8] The focus throw of my still lenses is short, can it be expanded?

9) Can lens breathing be corrected?

10) Can my lens be re-housed for cinema use? What is the cost?

11) Can my lens be converted to PL mount?

Continue reading Lens Mod FAQ

Diving Into Micro Four Thirds

Olympus introduced their Four Thirds system not too long ago. Then they dropped it and ran with the Micro Four Thirds system and it looks like they are going to run pretty far with it. As far as I know there are only two companies currently using the M4/3 system; Olympus and Panasonic. Olympus is utilizing it in their smaller interchangeable lens cameras which are pretty cool if you ask me. I purchased a Olympus PEN as a M4/3 test mule recently and I love it. And then there is Panasonic with a similar line-up of small cameras. However, Panasonic took it one step further with their new AG AF-100.

Continue reading Diving Into Micro Four Thirds

Auto Focus Cinema

RANT WARNING!

No… Just no. Auto focus for DSLR motion picture was a topic raised at a discussion panel I took part in this weekend at the PhotoCine Expo. Auto focus works great for shooting stills with just about any modern camera but it just isn’t appropriate for cinema. To clarify, I think it’s a must for shooting quick and gritty, reference material or home movies. But with the shallow depth of field and artistic styling of images rendered by a RED camera or DSLRs, it just isn’t a good idea. Nikon’s new D7000 does 3D facial focus tracking by recognizing a face and keeping focus on it which is cool, but why would you want to focus on just a persons face. What if the shot calls for a long, slow focus pull between two subjects that are 20 feet apart? Okay fine, you could use software and tell the lens to pull focus from distance ‘X’ to distance ‘Y’ and specify a given focus pull rate. But now you just have a mechanical focus pull done by a computer that has no emotion or feeling. There is no organic allure or life to the scene.

To add to this proposed flaw I present exhibit B: Auto focus lenses are loose and sloppy and don’t work well for motion picture. Due to their inherent mechanical pitfalls such as loose tolerances, low quality internal components, and short focus throw, this makes auto focus lenses a poor choice for motion picture since it introduces image shift, unreliable and unrepeatable focus marks, and other inconveniences. A cinema lens uses manual focus for a good reason. It keeps the image stable when racking focus and allows the shooter to pull focus in a way that expresses the emotion or passion that a scene should be able to convey. Basically, there is no way to instill life or humanity if you assign focus to a computer. When the day comes that a computer can carry out such tasks, I’ll be locking up my vacuum and hiding in my safe room.

(REVISION) Oh and I almost forgot to mention that pulling focus is more than just a tradition. It’s a craft that many have spent a career refining. This is why there is a job on a professional movie set for a “focus puller”. It’s not just a crabby old guy who doesn’t want to change his ways or embrace a new piece of technology, Auto focus in cinema just isn’t… Cinematic.

Zeiss T1,3 “Super Speed” Refurbishing

Zeiss’ T1,3 primes or “Super Speeds” as they’ve been deemed, are getting a little long in the tooth but still hold their own if well cared for. This is one example of such a lens. It is in superb condition optically but the exterior body of the lens has taken quite a beating. Particularly the painted rear housing surface. For some reason Zeiss thought it was a good idea to construct the rear housing out of brass instead of aluminum. This meant that the brass section didn’t receive the same anodizing as the rest of the lens but instead was treated to a nice coat of gloss black paint. Needless to say paint doesn’t hold up to daily use quite as well as anodized aluminum. In the much later models Zeiss switched to an aluminum rear housing with an anodized surface… Anyway. I didn’t think to take a photo of the rear helical housing prior to stripping all the paint, but you can guess the condition of the weak paint based on the anodizing blemishes and scratches. You do the math. So in this post I will show the process or refurbishing the rear housing of a Zeiss T1,3 Super Speed.

The old paint has already been removed and the surface is primed. I cleaned the engravings from any old filling to make sure there is enough depth to refill the engravings after a new layer of paint is applied.

Continue reading Zeiss T1,3 “Super Speed” Refurbishing

Still vs Cine Lenses

One might assume that a lens is a lens and you can simply adapt any lens to suit ones needs. This is usually a matter of changing or adapting the mount just so the square peg fits in the square hole. The fact is that still lenses and cine lenses are very different and can’t always be interchangeable. Still lenses are defined (in my opinion) as lenses that were designed and built for use with an SLR still camera whereas a cine lens would be one designed and built for use on a motion picture (movie) camera. I’ll go over why the two aren’t interchangeable and what can be done to reduce the differences between the two. Modern still lenses are designed for two things… Speed and ease of use. Continue reading Still vs Cine Lenses

Focus back on back focus

Back focus is a common term used to describe the Flange Focal Distance (FFD). Or the distance between the rear surface of a lens mount and the film plane or sensor. The most common FFD in my line of work is relative to the Positive Lock (PL) Mount system used on many motion picture cameras and lenses. The FFD for a PL camera is 52mm (2.0472441″) This means that when a lens is mounted to a camera correctly, the image produced by the lens should come to focus at exactly 52mm from the rear of the lens mount. Continue reading Focus back on back focus