Jump to content

Ruben Arce

Basic Member
  • Content Count

    124
  • Joined

  • Last visited

  • Days Won

    1

Ruben Arce last won the day on May 23 2016

Ruben Arce had the most liked content!

Community Reputation

9 Neutral

About Ruben Arce

  • Rank

  • Birthday 09/15/1981

Profile Information

  • Occupation
    Cinematographer
  • Location
    Salt Lake City
  • My Gear
    Ursa Mini 4.6k, Sony FS-700, Eclair NPR, CP-16R, Scoopic MS, Nikon R10, Nikon D810
  • Specialties
    Director of photography, Camera operator, photographer and editor.

Recent Profile Visitors

8176 profile views
  1. Are you sure that's a hair? It looks very straight and at a perfect 45° angle. I have seen several camera that have a markers / needles like that one so you can get some kind of information when you see trough the viewfinder.
  2. Obviously the camera had some work done. The aperture (iris) ring doesn't have the original cover and the leatherette seems sketchy too. You may have a crystal syn converted camera. It is possible to convert the R8 and the R10 to Crystal Sync and I have seen that kind of switches on converted cameras and I know that the modification is possible. Bad news is you may be missing an extra little box that goes with the camera when converted and needed to do the job.
  3. Marc, Using an external meter is not complicated and that's actually what I do with all my film cameras. The mistake some people make is assume the light meters matches the specifications of the camera, meaning there are some factors you have to consider before deciding what your exposure is going to be. I own a few R10s and I tested a couple of them using a light meter and a gray card and they were giving me pretty much the same F-Stop that I would get if I consider some compensations on my hand held light meter. There are mainly 3 things that you should consider when using a non professional camera with no professional lenses. Someone mentioned Shutter Angle. Don't assume that your camera has a 180° shutter angle, always do your research, In the case of the R10 I'm pretty much sure it is 160° so dial that number on your meter, calculate the number 24x360= 54th/sec. The second factor to consider is you are using a lens marked on F stops not in T stops, so simply ad 1/3rd of a Stop to compensate for the light loss in the lens, and Third factor is the prism that they use in the camera to split the image between the viewfinder and the gate, simply ad another 1/3rd of stop to compensate for the light lost in the prism and you are set. Pretty much you are going to compensate (not over expose) one full stop to get proper exposure. Then if you want to over expose the film a little to get less grain or because that's your preference you can do it. It would be a good idea to shoot a roll of film for sure, and even better idea to shoot a roll using a gray card and over and under exposing to see the effects rather than just shooting whatever. You could use half roll to shoot charts and half of it for real life situations. That's exactly what I do and most of the time my shots are right on the spot without the variations that a auto meter will give.
  4. I considered mentioning the CP-16r too because I think it's a great camera. It has a lot of modern components and it can be further modified to be even more functional. I understand there is a battery inside that was intended to keep track of footage when you change camera battery and that battery leaked on some cameras damaging some electronic components. I have two CP-16rs and they work fine, but looks like other people had that issue and I know a technician can remove that battery which doe no longer hols charge anyways. The CP-16 is kind of weird in some ways, but very functional and similar in ergonomics to what we have today in modern cameras. The operation and maintenance manual is avaibale online, but I can email it directly to you if you want it, it contains several schematics. I also have the "Inetrim Professional Technical Manual" another manual that has a lot of info about the camera, list of parts and components and at some point it has a lot of detailed information of the crystal sync system and some more schematics. Now that I saw that manual again I think it could provide you with a lot of information and you may get the idea of what they were looking for back in the day when designing those systems. I can send detailed high definition pictures of the gut of the camera too if you decide to take a look at it. Nobody wants to record sound on film anymore, so don't worry about the sound part, but some interesting things are the camera can be converted to U16 or S16 and a video tap can be mounted without removing the viewfinder. I have some other plans for that camera too that could make it more functional.
  5. I know you want to "create" a motor for your cameras and that crystal sync motor may not exist, but there are motors with old technology that work fine and that could be improved in some way. I mean I don't think there is anything wrong on reverse engineering a NPR or ACL motor that works just fine and just copy it or improve it. There are more cameras than motors and probably just using modern components would make them easier to get repaired for example increasing the reliability of cameras. You mentioned the struggle of trying to find another piece of equipment that it's going to fit your camera that it's going to be hard to find, you don't know if it's going to work and even if it works it's going to be old and you are going to be afraid of using it. Even the newest film cameras, motors, controllers and accessories are free of patent restrictions now. In the USA a patent protect an invention for 14-20 years and after that it becomes "free" or "public" and they created that system so people can take advantage of their inventions for a period of time, but also to make it easier for people to see how it was done, improve it. Even hole cameras could be copied at this time including design. I'm not saying it's easy or a great business but we have computers, CNC machines and 3D printing technology today that manufacturers didn't have back in the 60's. I'm sure is not easy, but maybe just copying some of those motors that already exist could create some cash flow that you could use later to develop motors that don't exist. At the end of the day film cameras being as complex and precise as they are, are simple machines compared to today's technology and some of them just need a motor and a CLA to bring them back to life.
  6. It's great to know you are working on this. I have been working on some simple modifications and accessories to make cameras more usable and I'm glad to know that there is people in other parts of the world working on creating this kind of stuff, specially complicated stuff like a crystal syn motor and with the technology that we have today like 3D printers and options to create inexpensive prototypes I hope you can make this happen. I have an Eclair NPR that needs a motor and I'm sure a lot of people with NPRs and ACLs would be interested as well. In my opinion 24 and 25fps are the ones that need to be crystal sync. I don't do a lot of slow mo, so for me 48, 64 or 75fps wild but close would be great. I don't know about the part of final users putting stuff together. I can do a lot of things, but I have no idea how to use an Arduino and I think most people would not be able to do it themselves, but you may find a partner in America and make it work that way. Keep up the good work, I'll be reading your updates.
  7. Is your camera still available? Can you send some pictures? Thanks
  8. I don't know if you tried using other manual lenses with the pocket and an external light meter before with different results, but in my experience the BM cameras are the ones who are not rated properly, I mean pretty much all manufacturers "lie" when it comes to ISO on their cameras. I have a BM Ursa Mini 4.6k and since I like using my external light meter I shot some tests to determine where middle gray was, long story short I determined that I had to use ISO 250 on my light meter when the camera is set to ISO 800 to get what I consider proper exposure. Manufacturers, specially at the time when those cameras came out were trying to under expose images to protect the highlights and sell the idea of a wider dynamic range. If you read the manual you will find a scale where they place "middle gray" at 38 IRE not at 50 IRE which is in the middle. I have a Sony camera from the same time period and with S-Log2 they were placing middle gray at 27 IRE, that sells the idea of higher ISOs on their cameras and help them to protect the highlights avoiding blown up highlights and making their cameras look "better". Most people don't use the middle gray method, they use false color, zebra, wave form scopes and that kind of stuff, most people don't use an external light meter these days and RAW and LOG formats allow them to say their cameras are rated at ISO standards, but it's tricky. The Meteor lens is not rated on T-Stops as you mentioned before, so add another factor there, I would say one third less of light maybe.
  9. I did the same thing a few years ago. I had some bulk Ilford HP4 and I wanted to test my Konvas 2M. I did loaded some film on a core, loaded the camera, shoot with it and everything was just fine. I just wanted to test the camera so I was more than happy with the results. I didn't shoot much, but I didn't get weird reflections coming back from the pressure plate or anything, just some nice sharp images.
  10. I read your post since the first day you posted it, I have been working on modifying camera mounts and the K3 is one of my prospects. I shot several times using M42 lenses with the K3, actually I used to have a set of lenses for the camera that now my friend in LA owns, it is perfectly possible as everybody told you here, but I didn't know if I wanted to try to say something when you are so reluctant to hear what people have to say, specially when every thing people told you here is right. You are kind of right on the info that you have about FFD but those people actually have it right. It's not that complicated really, and as you pointed the information is online, but if you don't want to accept that info I don't know what you can do. I shot 4 times using the K3 with my set of lenses: Zenitar 16mm f2.8, Vivitar 28mm f2.8, Super Takumar 50mm f1.4, I can't remember the brands on the other ones, but I had an 85mm f2.8, a 135mm f2.8 and a 200mm f4, so here is a setup from someone who had actually shot with a K3 and M42 lenses and here are a couple of HD samples of films shot with the K3, the first one is when the camera was regular 16 (cropped) and the second one converted to Super 16. All the lenses used on this two tests are m42 lenses desiged for still photography. https://youtu.be/StGgzgXf-rg https://youtu.be/bNXQs4DBOv0 Do I have experience with the K3? Well I converted the camera that I used to shot those films to S16 myself, I lubricated it and replaced the light seals, I bought the re-centering ring and I tried to adjust it to get it close the the appropriate FFD and I shot 4 rolls with the camera that are sharp and that let you see what the camera and the lenses can do. Every M42 lens that I had was different, they looked different and I wanted to move on to better cameras and lenses so I sold that one and the lenses. I recently got another K3 that I'm going to use to experiment with mounting lenses. The information that other fellow members presented was correct. The FFD of the M42 mount is 45.46mm and it is the same on 35mm still photography cameras and on the K3. Getting a camera serviced is extremely important, because a technician will adjust the FFD, and the focusing screen distance. You have been talking about the FFD as if it were the only important part of the camera and it is not. You may have a FFD perfectly measured and if your focusing screen is not at the right distance you are going to see images out of focus on the viewfinder. You can have a perfectly set FFD and focusing screen distance and if you don't know how to adjust the diopter you may get out of focus images. Now you think FFD is critical and it is, but the camera will still work if the FFD is not right on the spot. I did modify the mount on my K3 with sand paper and I never had the FFD adjusted and I did get sharp images every time, the difference is if the FFD is not set correclty you cannot trust the measuring distance (witness marks) on the lens so you cannot grab a measure tape measure at 10ft and then set the lens at the 10ft position and expect it to be right and your lens may not focus at infinity depending on where the actual distance is set. Focal Flange Distance is important, yes, because if it is properly set you can trust your camera and lens even when your eye is telling you something different and you can get images in focus even without a viewfinder. If your friend didn't get images in focus it may be because the focusing screen was not at the right distance, or because the diopter was not set correctly. I really recommend "The 16mm Camera Book" (Underdahl) you can learn a lot from that book and you can learn how a camera is actually tested. The best way to know if a camera is right on the spot even after being serviced (to make sure) is to shoot film. I do test my cameras at home shooting B&W film that I process and scan here. If FFD is correct, if the focusing screen is at the right distance and if the diopter is set using measurements and not your eye, you should have sharp images every time, and you should be able to tell by looking at the viewfinder. I'm not sure I want to have a discussion or conversation with you about this. I hope you get some useful information, you can see some samples, so you can see it's possible. I'm sure other members have footage but they didn't want to deal with your attitude. People here are very nice and very, very helpful please don't disrespect them.
  11. I don't think your footage looks terribly bad. 16mm film is going to look soft if you compare it to digital specially footage from DSLRs with big sensors to begin with. When it comes to exposure I have seen a lot of people assuming that they have a perfectly serviced camera running at 24fps and a 180° shutter. Tyler already mention this, but I'll put it in a different way... If you are using a Bolex that hasn't been serviced you don't know if it's running at 24fps for real (Not a crystal sync camera anyways) so you may be losing or adding some light there. You have to find what the shutter angle on your camera is. Shutter angle is different from one model to another. When it comes to Bolex cameras you are going to find numbers like 133, 144, 165, 170 & 190 degrees depending on the model, assuming you have a regular H16 Reflex bolexcolector.com states the camera has an actual shutter angle of 144° (1/60th) Now some people will tell you to meter at (1/80th) to compensate for the light lost on the prism. If you are assuming the camera has a 180° shutter (1/44th) you are losing a third of a stop there, if you are not compensating for the light that is lost on the prism, you are losing another third of stop there, so far you are underexposing by two thirds of a stop. Now let's say you are using lenses that are marked in F-Stops instead of T-Stops and you are not compensating for that (you typically lose another third there) you could be underexposing by a full stop at that point. Shutter angles vary from one camera to another, the K3 has a 150°some S8 cameras have shutter angles of 220° Profesional cameras 180° for example. After considering all those factors I give film a 1/2 of a stop of compensation (overexposure) to keep grain low and to keep some info in the shadows. Soft Image... You don't mention how you are judging focus. You may be adjusting the diopter to your eye and then focusing by eye, that's what you are supposed to do right? Well it's not a digital camera... What you see may not be exactly the same thing the camera is capturing, the Focal Flange Distance is very important and it it' not perfectly aligned you are going to get soft images, specially with wide angle lenses and small f stops. If you are sure the mount of the camera (FFD) is right on the spot then you can use a measure tape to set focus on a chart and then adjust the diopter to your eye. You can do this shoot some b&w film, process it at home and see the results. Some people will tell you to adjust the diopter at a point where you can see the "grain" on the focusing screen, but if the focusing screen is not at the right distance you are going to get soft images. I mentioned wide angle lenses are more prone to show this problems, since this lenses project a very shallow back focus image. The viewfinder on the regular H16 is very dark, and focusing a wide angle lens on a 16mm camera is not an easy thing even with better viewing systems. You may try putting a lot light on your subject for a moment just to make sure it really is in focus, but again if you are not sure the camera is right on the spot it's going to be complicated. Are you using adapters? There are a lot of factors that you have to consider when shooting film.
  12. I agree the cost of shooting film is kind of expensive, specially if we compare it to the no cost at all of shooting with your phone or a digital camera, but if you miss shooting on film, enjoy the process and have fun you could shoot Ektachrome 100 on a Super 8 camera, get it processed and project it at home. (still kind of expensive) You don't have to get the film scanned every time and certainly not at the highest resolution.
  13. Well if your camera was converted to S16 I think it's a good idea to use other lenses, so you can take advantage of the S16 area, but don't forget that you get a 3X crop factor with S16, so a 135mm is going to have a field of view of 405mm for example, if that's what you need great, and you can get some 8mm lenses with Nikon mount now, so I think it's a good idea. Focal Depth or focal flange distance is both easy and complex. It's easy because as long as you have a lens set to the proper distance (46.5mm for Nikon) the lens is going to work as intended. The difficult part is to get it there. I'm not a camera technician by the way, but I understand how those things work. So basically your technician has to adjust the lens so it is centered and then with proper tools set the focal flange distance properly, by measuring obviously and then when it's close to proper distance they use shims to extend the distance or they have to machine the part to reduce the distance depending on the case, so easy to understand it, not so easy to do it. A camera technician should be able to do it, specially one who can modify or make parts using a lathe or a CNC machine. I got a K3 with the only intention of converting it and modify it in several ways. I have some manual Canon lenses so in my case I want to go that way. I'm going to design mount and 3d print a prototype and if everything works fine I'll have it machined. I'll let you know how it goes.
  14. Nikon lenses are good. The lens that comes with the camera is not bad, it's actually kind of good, the thing is if you want to convert the camera to S16 the Meteor (kit lens) is not going to cover the S16 area below the 27mm position. Technically it is possible to convert the camera to Nikon mount since the focal flange distance of the Nikons is longer than the M42 one. I just got a K3 in like new condition, and I'm going to convert it to S16 and I'm going to try to give it a Canon EF mount. You can always use M42 lenses too, but to be honest if your camera is not S16 and if you don't need wider or longer lenses, I think the Meteor works just fine or better than other ones. Lenses designed to cover the 35mm full frame can cause internal reflections. I used M42 lenses with another camera and I didn't see any problems really, but you are adding another factor of risk.
  15. The system that moves the loop formers out of place is made out of threads, which in the best case scenario is at least 30 years old. If the system doesn't have enough tension the loop formers don't move far enough causing scratches and in "registration" issues. I would definitely remove the loop formers. I just got a K3 to play with and that's one of the first things I'm going to do with it.
×
×
  • Create New...