Lens Database for Preston HU3

[Alec Jarnagin SOC]

Greetings. I'm writing this as an open letter to fellow operators (I'm especially interested in opinions of ex-focus pullers) to get feedback on setting up a standard protocol for naming lenses with Preston's HU3 hand unit. Having spoken with Erwin Landau and Howard about this, it seems a very good idea.

 

A database is in the works, allowing users to download lenses from it directly to the Hand Unit 3. It will take considerable time and effort to build this database to incorporate lenses from around the world. The advantage to this is that once a lens is entered it is good to go, but eventually this database will be too large to store inside of the HU3 and use in any practical manner. Ideally, you'll be able to search the database by lens manufacturer, serial number, and locality. To make this system work, it behooves us to establish a naming protocol for lenses as we enter them into the database. This way, the listing of lenses will conform to one standard and make the database infinitely more useful.

 

Information needed in each name would be manufacturer, focal length, and part of the serial number identifying the individual lens. The name needs to be very simple and quickly identifiable to an AC scrolling through your hand unit on set.

 

An example would be:

 

PV-PS-40-XXX

 

The "PV" denotes Panavision. The second "P" denotes it is a Primo lens and the "S" stands for spherical. The "40" is the focal length and the "XXX" is the last three digits of the serial number.

 

By this formula, a Zeiss standard speed 24mm would be: Z-T2.1-24-XXXX

 

The more I think about this though, the trickier it gets. What about lenses met for 16 cameras? Most companies don't have anamorphic lenses, yet Panavision has Primos in both flavors. This is why we need feedback. It is too easy to overlook something. One solution would be to take Panavision's catalog numbers and insert a PV in front with the last three digits of the serial number on the back. This might not work as well for other manufactures though and of course, the chances of having a catalog handy when entering data is slim to none.

 

Obviously, you could rename lenses on set in your hand unit if you wanted to, but I'd really like to see an easy identification system put into place before this database gets underway that could work on set as well.

 

Begin the thinking.....

[Yookidoo71]

Hi Alec,

 

I'm patiently awaiting the delivery of my HU3 and am curious about your post. A world wide database of lenses, down to the specific serial number implies to me that the system is not trully repeatable from on eg. specific focul length Primo lens to another? Am I understanding you right? Perhaps a call to Howard Preston is in order.

 

Jeff Clark

[Erwin Landau]

The idea with the world wide database came about when I was talking to Alec yesterday.

 

How the calibration works is that the MDR runs the lens through its cycle to determine the physical stop at the far as at the near of the lens, then the assistant creates a focus ring that lines up with the hard marks on the barrel. The problem is that, as the lenses are hand assembled, they have a 2 to 3% discrepancy in travel from near to far. From lens to lens even if it's the same focal lengths...

 

So with the HU-3 you calibrate the lens by "reseting the lens" as done with the HU-2 but instead of marking a ring you use the menu function and pick six reference marks that will give you an accurate spacing of the hard marks in conjunction with the marking rings. (You get 6 rings that differ in the near side, but you can use one ring for the entire set of lenses if you want).

 

On the prep you basically "program in" your lenses and this lenses will be available until you delete it or edit it for another lens set (you can create a permanent library as well as temp ones, all lenses put into the temp will have a copy in the Library, the library is permanent unless deleted... think I-Tunes).

 

So if you are already going through the motion, why not share the files with a data base and next time someone gets the same set he just has to down load them onto his hand unit. Each and every lens will have its individual set up and would be defined by its serial number... (last 4 digits)

 

It's a drag at first but after a while most of the commonly used lenses will be in the data base and the lens prep would be just as long as it would take you or your AC to check the serial number and down load it from the website... and when you put them on maybe double check that it lines up...

 

Breaking it down by Continent, City, Rental House... (To find the lenses) then Make, model and last digits... and that will stay the same for quite some time...

 

Of course if the Lens gets over hauled at what point the hard stops would change, but that is one of the set...

 

It's just an idea... a brain fart... but it could be so much more...

 

Let me know if it's a fantasy or a valuable idea,

 

Sincerely,

 

Erwin

[Imran Naqvi]

I neither own nor am likely to own a preston soon (unless someone wants to give me a REALLY nice birthday present), but a few quick questions.

 

1. How much information can be attached per lens entry in the HU-3?

 

2. How much of that info can be displayed on screen?

 

3. Do all lenses go in one big long list or can they be split into categories i.e. manufacturers, primes, zooms etc?

 

If you'll allow me an opinion, it makes sense to attach as much information to the lens entry as possible and without wanting to sound clever after the fact, one really useful feature that hasn't been mentioned would have been the ability to load profiles from a memory card, this would allow you to store as many entries as the card can hold and hold much more information per lens should you wish to.

 

Hope this helps.

[Alec Jarnagin SOC]

Jeff,

 

I think Erwin's post should answer your question, but I'll add that in some cases you may find two lenses of the same focal length from the same manufacturer match (or at least are very close), but as Erwin stated, these lenses are hand made and have a small degree of differences.

 

As for the database, no one is saying you have to use it. No one is saying you even have to use the lens mapping on the new hand unit - you can shut it off and use blank rings and do things exactly the same as you did with the HU2. My feeling is that if the database is easy to use, why not? Some people may opt to manually set up each lens as it us used for the first time on a job (or at prep if possible) because it only takes a minute (probably less time than marking a blank disk), but again, I think if the database is easy to use....

 

As for it being a world wide database, that is an extreme goal. If I had said a "US" database, I'd get in trouble for leaving others out, etc. If we use a simple formula to name lenses, the sky is the limit as we combine databases, etc as time goes on.

 

Imran, yes, the database in the HU3 breaks things down by manufacturer but this info still needs to be in the title else we risk getting lenses mixed up. There are subcategories in the HU3 so you might put all the lenses for a given job in list "A" but it is possible you'll have lenses from more than one manufacturer on that job.

 

As for memory card, the HU3 does not allow for this, but it has a cable to interface with your computer (Windows only). From there you can download from a CD/DVD/Internet or even memory cards.

 

I hope this clears some things up.

[Charles Papert]

As for memory card, the HU3 does not allow for this, but it has a cable to interface with your computer (Windows only)

 

Guess that cable won't be interfacing with my computer then!

[Alec Jarnagin SOC]

"Guess that cable won't be interfacing with my computer then!"

 

Charles, I would have the same problem except I still have an old PC laptop sitting around from my darker days. Howard points out that new Macs can run both OSs and some Macs have a windows emulator (?). You should let him know your situation as I already mentioned a lot of us are Mac users. Hopefully a Mac version will come along.

 

Now, any suggestions for a formula?????

[Charles Papert]

Yeah, I know. The Intel Macs can run Parallels and thus XP just fine. Still sort of--icky, though...!

 

It would be interesting if Howard polled his user base--I have a strong feeling that the percentage of Mac users is well above the typical <5%, and may even be in the majority!

[Lawrence Karman]

Yeah, I know. The Intel Macs can run Parallels and thus XP just fine. Still sort of--icky, though...!

 

It would be interesting if Howard polled his user base--I have a strong feeling that the percentage of Mac users is well above the typical <5%, and may even be in the majority!

 

 

I was told by a salesman at an Apple store that while the Intel Mac was capable of running Windows, you voided the warranty as soon as you used it in Windows mode. too many virus opportunities in that mode. I never heard them advertise this fact.

 

I don't mean to sound negative here, but your new Preston toy sounds like it is using up a lot of your free time. Are you guys camera operators or focus pullers? Move on and let the AC's work this stuff out.

[Alec Jarnagin SOC]

Lawrence,

 

"I don't mean to sound negative here, but your new Preston toy sounds like it is using up a lot of your free time. Are you guys camera operators or focus pullers? Move on and let the AC's work this stuff out."

 

I happen to be spending a few days doing pre-pro while working with a friend on a new web site. These activities seem to be keeping me at the computer, but that is not the point. I assure you that I have spent less time on this database thus far than I have deleting spam on this forum for you and others to have a better experience here. It is actually Howard and his wonderful people at Preston Cinema that will be running this database (with field users uploading their data). We were merely looking for a good way to get this system up and running so a suggested system could be outlined in the owner's manual, etc. Clearly you don't think this is of use, so thank you for your input.

 

The funny thing is that I was originally going to email this inquiry to a select list of operators that I know and respect, but as a moderator and a firm believer in this community, I thought I ought to include everyone. Pardon me for thinking that saving time on set was not just an AC's problem.....

[Afton Grant]

I don't mean to sound negative here, but your new Preston toy sounds like it is using up a lot of your free time. Are you guys camera operators or focus pullers? Move on and let the AC's work this stuff out.

 

I'm not sure that's the right path to take. As OWNERS and operators of our equipment, I think it is our responsibility to not only know it inside and out, but to help promote advancements in the technology. If we just bought the equipment and let others use it and learn it, how would we intelligently communicate with the ones that manufacture it? It is that communication that makes things better.

 

Not to mention, I'd cringe at the thought I just spent that much money on a piece of equipment, only to hand it off to someone else to learn and use.

 

Upward,

Afton

[Eric Fletcher S.O.C.]

Yeah, I know. The Intel Macs can run Parallels and thus XP just fine. Still sort of--icky, though...!

 

It would be interesting if Howard polled his user base--I have a strong feeling that the percentage of Mac users is well above the typical <5%, and may even be in the majority!

 

 

I was told by a salesman at an Apple store that while the Intel Mac was capable of running Windows, you voided the warranty as soon as you used it in Windows mode. too many virus opportunities in that mode. I never heard them advertise this fact.

 

 

The salesman was full of it. Windows has it's own partition and windows virus don't affect Mac's.

[Charles Papert]

Windows only has its own partition with Boot Camp--it does not with Parallels, which runs it virtually, off the same drive.

 

Not sure about the virus issue, nor the claimed voided warranty, but that would be useful to know about.

 

The issue of who should be spearheading the lens database project seems like an unnecessary one to have to debate. If one invests that much money into a piece of gear, it makes perfect sense to get involved with the R&D aspect of it, if one has the time and inclination. It's always a surprise to me how many assistants are relatively technophobic and prefer to only learn the bare essentials of the more esoteric pieces of gear (unless they own it themselves, perhaps). Actually, I'm not sure if I've ever seen an assistant figure out the sometimes fascinatingly complex science of mounting focus and iris motors as quickly as I can do it--not like I'm some wizard, but it often seems to turn into a fumbling match when the guys take a crack at it. Something about juggling the four different ways that a motor can be mounted to a single PAM arm combined with the position of the motor up and down the arm, combined with the variable angle...but I digress (as usual).

 

I'm with Ron B. on this--make it all work tidily boys, so that if and when I jump into the HU3 you've done all the hard work for me. Have at it!

[Denny Kortze]

I'm currently making my living as a 2nd AC in New York. I just bought a Pro sled/vest and 3A arm and am on the wait list for the new Preston hand unit (although I am considering purchasing the older hand unit used).

 

A lens database would be great, however it would only work if the camera assistants were very dilligent in uploading the info off of each lens they use after each job. My guess... most assistants would not even know such a database exists and a lack of particiapation would make it useless. Besides, the workflow is actually more involved in searching, downloading and uploading files on the internet than simply throwing the lens up and calibrating it manually. Even if you did get lucky and find each lens on the database, each lens would have to be checked anyway to make sure that it lined up. Manually calibrating at that point can be done rather quickly.

 

No two lenses are the same, however no two hand units are the same either. At least this is what I have encountered with the Hand Unit II when I have tried to use the same focus ring for the same exact lens on a different hand unit. It usually does not line up. This typically can be fixed by changing the witness mark on the hand unit with tape as you would be using the the same lens with the same stops and distance markings.

 

I am specualting on how the new hand unit functions, so I am posing a question as well as a possible solution to this problem. The stops on the barrels of each set of prime lenses will usually be different, however the distance between two given distance markings on the lenses should be the same. You could calibrate the lens on the camera to set the stops on the focus barrel of the lens, than set the lens by comunicating to the Hand unit where two given distances on the lens were, for example 2 ft and infinity. If this worked, you would only need to break the lenses down by lens series rather than each individual lens which is my understanding is how it is currently set up.

 

I am always open to new ways of doing things and would try to be an active participant and contributor to the lens database, however I predict I would be one of the few using it and the database would only be as good as the amount of information being uploaded to it.

 

Denny Kortze

IA 600 2nd AC

[WillArnot]

Sure leave it to the AC. But what happens when you are stuck on a job with a bonehead AC who doesn't know any better? You just gonna point the finger?

I for one like to have an educated solution. As Alec suggested, I asked a few of my AC buds what they thought. Eric Swanek just finished up American Gangster shot by Harris Savides starring Russell Crowe and Denzel Washington. He is one of the elite AC's that I have the pleasure of working with. Here is what he wrote back to me:

 

As far as the focus thing, it could draw me deeply into the intricacies, but I don't know if I want to go there. The question I have, is will the new Preston unit have a screen ala the Arriflex remote LDS or the Panavision RDC? I gather that's what the database would be for.

 

The problem with this is the following: it takes longer to scroll through a list to get the correct lens data than it is to pop a ring onto the focus knob. What is a killer(with the Arri LDS) is that EACH HANDSET requires a different ring for each lens, as the travel on the handsets & motors are different enough to warrant this.

 

I normally only use one ring and calibrate it as necessary: If I'm on a longer lens, I'll limit the near focus (or the far) so that I get the maximum amount of travel where I need it, with a buffer. For most situations, it'll be from 3' to inf.

 

With Primos, most lenses fit this within a very near margin from 21 to 50. On longer lenses, I'm limiting more. With standard Primos, the focus changes from the standard logarithmic scale when from 2'-3'. This is because focus is logarithmic from the "Optical center" of the lens. Lenses like the 50 have an optical center farther from the film plane. At distances greater than 3-4', this offset is a minor percentage of the total distance focussed, so the farther distances fit nicely into the logarithmic curve.

 

The newer "Classic" Primos and the Cooke S4's (I'm not sure about the Master Primes, nor the Ultra Primes as I really haven't used them yet) are close focussing lenses that have a secondary "high speed" focus when nearing minimum. This allows you to pull normally at regular distances(unlike using close-focussing lenses), and then kick into high gear when getting close. The problem is that it is very inconsistant where this high speed area is, not only over focal lengths, but I gather over different lenses of the same series.

 

As the thread stated, AC's are not always crazy about trying new things. Even I haven't gotten too far in using the LDS screen for the Arri remote. While it does some things really well, on lenses that are not "smart", such as zooms, you have to use an "archive" system. This is a database made by CSC with all their lenses in it. Unfortunately, the original software & the "Yellow" update are not able to make it work. I was constantly frustrated with zooms going backwards. Reversing the motor direction caused the scale on the screen to flip as well. I just want the scale to look the same on the screen as it does on the AC side of the camera: inf, telephoto, & wide open @ the top.

 

However, the Panavision RDC has a different problem: the zoom size is listed by mm and not by a graphic. It's very hard to judge zoom speed on the wide end or the tight end as the numbers change so strangely (17.5, 17.6, 17.7....65, 70, 75). And, as much as I like doing puzzles, I really hate the whole process of mounting motors onto the camera. It's never easy as every set of lenses has at least one oddball that makes you move motors around. The only one that ever got it right was the Panavision RF&T which replaced the focus knob and engaged focus & T-stop from beneath. Unfortunately, they made their later units "universal." Even the Arri motors, which are one of the easiest to set up, has a flaw that the iris motor has to be on a dogbone to get around the mirror housing. Sure, some operators figure they have it all figured out, but most of them do their damnest to block the view of the markings on the lens. I for one, would still rather be as close to the camera as possible, looking at the lens to see where I'm focussed.