Aapo Lettinen

Just a follow up on the 1000w + 650w + 300w kit I purchased in 2014 and about the new 150w fresnel I just purchased recently. The 1000w still works and the 300w is pretty OK though the spot adjustment knob is tight and needs some force to turn. Bad lube on the axle is the most probable reason. The 650w has the spot adjustment completely frozen and it cannot be used correctly anymore or repaired completely. The lubrication which was not good in the first place has dried off and fuzed the axle completely so the light cannot be repaired and I will most likely throw it away. One of the three stands still works correctly and the other one has loose spigot but otherwise it is pretty OK. The third stand has so many problems on the spigot and the locks that it cannot be repaired and I have to throw it away. So I still have two of the three lamps somewhat working after 6 years and one working stand plus one almost working one. And this was after repairing all the lights before first use. Mind you that the 1000w did not work at all out of the box because a wire was loose inside and the other ones had loose connections which needed to be repaired for safety reasons. All in all, I don't think these Chinese lights are suitable as a long term investment for cinematography projects. They are cheap and need to be repaired and only work correctly after that for couple of years before developing further problems. My lights have earned their price back multiple times so I am perfectly happy to retire the non working ones. But just for you to know that these lights don't last forever like the real Arris. And the 150w one? Just as bad quality control like with the other lights back then. Wires a bit loose here and there and I needed to add spacers to the screw to be able to close the light completely after installing the bulb. One of the original Chinese bulbs was broken right out of box but the other one worked correctly. Like with the other lights, I expect this thing last for only three or four years before retiring it. And it needed repairs too before use.

The main issue would be that most people don't have the mechanical expertise or machining tools to make the conversion by themselves. I have understood that the russian k3 mod is with a wild motor and not crystal sync? I would expect it to be crystal for that price but maybe they have issues designing one?

as for the swappable tungsten/discharge bulbs on the Arri 250. It is neat to have this option but I can't imagine many situations where swapping the bulbs would really be practical compared to just having separate tungsten fresnels available and keeping the 250s always with the discharge bulbs installed. One does not normally change bulbs in the middle of the shooting day because there is no time for it (waiting for the light to cool and so on) and one loses all the benefits of the changing option if it cannot be easily done between shots or scenes. Additionally tungsten lights are cheap so I would just get comparable tungsten fresnels separately and keep the 250 lights always equipped with the same bulbs. Having the discharge capable lights and using them with tungsten bulbs would just feel wasting

personally I think the under 400w range is pretty well covered with LEDs nowadays. If you are handy and know enough about electronics to do it safely you can even build a cob led light by yourself, I am just building a 100w one and will make a much larger system after that. The 100w system cost something like 60 euros for the parts including the 31v 150w mains power supply and the bowens mount. will make a housing and controller system for it next :) the small hmi's are OK if you can get the light for cheap and it has a working bulb. they are heavier than leds but they have the advantage that the bulb can be changed when it ages. When your expensive cob LED light ages and develops colour shifts you can't do much than to curse it and buy a new one. ( on a recent feature shoot we had couple of Aputure 300D mk1's which were less than two years old and already had huge green cast. they were so green that I did not want to use them unless I absolutely had to when running out of lights... I used them maybe 3 times during the whole shoot. they were just too ugly and sad to use. So if your expensive Led light goes green and does not have g/m correcting or cannot be gelled, then it was complete waste of money because even if you COULD use it, you just don't want to and it stays in storage most of the time.) The advantage of building your own light is that you can actually replace the led chip to new one by yourself if the old has colour shifts. That is pretty huge because you can't do that by yourself for factory made leds and it would be very expensive to get the chip replaced by the manufacturer even if it would be possible.

Due to eBay's updated payment management policy, this item will not be available via eBay anymore. Contact me directly via PM if you are interested in this product. I have a sine wave version coming out in August as well.

You need to know someone from the crew first so that they can recommend you for the job. It depends on the job position who you have to know but if you want to be the dop then you generally need to know either the director or the producer to get the work... Or have a killer reel which they have happened to see. Knowing people is they key in the film industry. If there is two or three good options for a job they will hire the person they have worked with before and who they know will do good work.

one could make a linear ccd one in reasonable time if it only takes single measurements so that the readout from the sensor can be low with low sensor clock speeds. then the stream could be read directly by the microcontroller. If it needs to read at high speed (like for imaging applications) then it will become challenging. but no one needs such readout speed for a color meter anyway. if making a meter it should be either very simple and small and efficient to make sense, or alternatively one could make one as a passion project and just not care how much time and resources it takes to build one. Personally I would rather take the small and simple one because I am only needing this type of meters for colour temperature and green-magenta shift measurements. if it would need to measure highly saturated LED light hue values accurately, then it would need to be more complicated. But one can manage without such meter in most shooting situations by just planning more carefully and using apps if needed. Like always, one needs to evaluate what one really needs and which specs would be nice extra to have but more rarely needed. Making the simplified systems is easy but if one wants to include all and every possible features in a single device, then there is no other possibility than to make it as a passion project and spend even years of your life to the project. To me, that kind of dedication makes no sense at all. I would rather spend the time making something useful like actually shooting something than to waste time building something which is not needed ?

Finished the 24v battery for the system. It uses two 12v gel batteries in series and has a on/off switch and fuse holder. Long cable to allow keeping the battery on ground when operating. Pretty neat battery because the small shoulder bag is handy and excess cable can be stored easily inside the bag. Output is via 3-pin xlr ( 1 = gnd, 3= +24v ) . I will make a higher voltage battery for higher frame rates. I should complete the 15epss crystal sync controller in a week or so. Will post results then ?

practically one would just need to compare it to other meters to narrow down the calibration until it is good enough to be used for work. I would measure different sunlight situations and tungsten lights for starters and then move to discharge and led sources. I was thinking a simple sensor with 3 photocells or photodiodes and rgb filtering over them, then either a preamp or directly to a microcontroller and all the calibration done in software

Brand new bulb on the left and the old bulb from a eBay HMI on the right. If the bulb in your second hand HMI looks like that on the right, then get rid of it and buy a new bulb right away (it can be used still but has colour shifts and has striking problems and increased risk of exploding. You don't ever want a bulb explode in you HMI light if there is any way you can avoid it... may damage the fixture quite a bit like Phil said)

Magnetic ballast hmi:s may have visible arch flicker depending on the bulb type and burning position. In most cases you would want a high speed electronic ballast for all shoots unless you dont have any choice. I just purchased couple of old 575 hmis for low budget docu and 16mm indie stuff. They were 8 times cheaper than similar output led light so I can live with the downsides. But if price is not the main criteria, then I would avoid the magnetic ballasts. The easiest way to see if a bulb is likely good or not is to look the glass of it. A newish bulb has pretty clear or perfectly clear glass and you can clearly see the electrodes. A old bulb has eroded and hazy glass and the bubble may asymmetric and the electroded much further apart. I would not bother with the old bulbs, just calculate the price of the new bulb to the total price of the hmi set and replace the old bulb right away before using the hmi for work

the schematics can be worked out using the circuit board and datasheets of the components. probably I would want to open the actual meter too to see what is inside. But frankly speaking, that is so time consuming that I could probably make my own colour meter from scratch in the same time. I would probably use a attiny84 or atmega 328p microcontroller depending on the user interface needed. it would have a small oled display and it would be about 1/5th of the size of the Colour Meter II but a bit more accurate and had more functions

Without watching the videos, to me it sounds like that the lens mount has a mounting problem and the weight of the lens shifts the ffd during the shoot, or it could be a ground glass /mirror problem. Pressure plate issue or mag mounting issue can do that as wellbut pressure plate would make the problem more inconsistent. So I believe the weight of the lens causes something to go out of tolerance slowly during the shoot. Something may be aged or loose, I would send it back to service to find out the exact issue

it seems possible because the transmission is so poor on visible light. It is OK if the pickup camera is sensitive enough but I am planning on shooting mostly 100 iso films to be able to use the tap better

I think the orange is due to the viewfinder prism's coating affecting the transmission of light. I don't know if the original video beamsplitter has any colour shift but the normal prism (like I seem to have in my camera) is likely not meant for video tap use and thus it just has the regular (aluminium?) partial coating which affects colours when shooting through it

I am using a self designed simple prototype board for my own tests which is single speed 24fps and does not have shutter park or film counter etc. Plus it does not have soft start or anything. If installing this type of controller to a external box so that the board does not have to be redesigned to fit inside the camera, then I would already have a single-speed system available. The reason I would want the final system to have more features is because it is time consuming to take out the old electronics and design new boards which fit inside the camera. everything has to be tested in the end as well so it is lots of work to convert this type of camera and thus it would be nice to have more features in the end than a very basic controller I currently use for the tests. the external box single speed conversion would probably cost something around 500 usd + shipping and the planned final system with 10 to 12 internal speeds and all the shutter parking and film counter etc. features would be around 1000 or 1200 usd + shipping so to me it makes more sense to wait for the final version

from about 30cm away it is very difficult to detect the unexposed back element of that Super Takumar 55/1.8 with that geiger counter I have. So to detect anything you need to be very close to the glass element and it needs to be unshielded or very lightly shielded.

btw, everything around you including the air you breathe and even yourself are radioactive. it is completely natural and I would not worry too much about it unless you are going to eat or drink something excessively radioactive or will going to inhale radioactive dust. In the case of the film camera viewfinders, I would worry if one would take out radioactive elements and glue them to their eyes so that they would carry them on their person 24/7 for many years. I would expect some kind of eye radiation damage from that kind of use but if only using the camera like it is intended to be used, then should not be much of a problem

Over the back element with plastic lens cap on: Back element from half a centimetre away with no lens cap: A 8mm thick glass filter simulating how much radiation is blocked by a glass element. compare to the previous pictures.

if you need to shoot with the 16s then there is nothing you can do whether it having radiation sources or not. Personally I would not worry about it unless wanting to take out the glass elements and grind them to dust... just for the fun of it, I tested my Super Takumar 55mm F1.8 again with the basic geiger counter I have. You have to take the counter very close to the lens to detect anything (just like a spherical light source, the intensity lowers very quickly when distance is increased) . if you want to be couple of centimetres or millimetres from the lens elements then you can get a high reading. from 20cm away the radiation level is very minimal. And as said, the glass elements block most of the radiation. The "hottest" part of the lens is its back part where the thorium containing elements are most exposed. Most of the elements don't contain any thorium Background level: Directly over the front element:

thorium glass is very easy to detect with a geiger counter, even with a model which is mostly sensitive to gamma and beta rays. when brought close enough to the glass the counter will go nuts if it contains thorium. If it only has couple of extra ticks over the background radiation then it probably does not have any thorium in the glass. any material between the counter and the glass blocks some of the radiation and if the prism is inside a camera you may not detect anything at all. If there is a direct line of sight to the glass surface or there is nothing more than a plastic lens cap or similar in between, then the counter should have A LOT higher reading than the background radiation is (it goes from couple of ticks per second to thousands or tens of thousands per second. cannot miss it)

Don't know about the thorium history of these cameras but if there would be any in the visible outermost glass surfaces it would be very easy to detect with a geiger counter. If it would be in the middle, the glass surfaces would block the alpha radiation the thorium generates and the ratiation level should be neglible or even undetectable. It is this way with lenses like super takumars. Radioactive but easily blocked. I have understood that in most cases the yellowing is happening in the canada balsam surfaces and not the glass itself and it is not happening in all lenses at the same pace

so it would be from 3k to 10k developing costs and then the final system installed in the camera should cost between 400 to 800 usd depending on the complexity and the camera model

it would be much easier to make a new in-camera optical audio system from scratch than to develop a new mag striped sound film from scratch. Maybe some very low-end mag striping service could be possible with the normally available resources but anything which would need to be high quality and reliable would be very expensive for the person doing it. Custom making mag striped sound film would be possible with a Kickstarter project or similar crowdfunding campaign. Otherwise pretty much impossible by my opinion unless someone wants to throw in tons of his/her own money as a kind of charity campaign to make few other hobbyists happy. Developing the optical sound system for a camera would cost something between 3k and 10k if done right and if the camera model is easy enough to modify. Most of the cost is prototyping and physical testing ( = hard work) which takes lots of time and needs lots of film stock and processing. The largest issue with optical sound for 8mm is that the projectors need to be modified too (though much easier to modify than cameras) . By my opinion, in-camera sound for 8mm is mostly a niche feature which is only practical for home videos and other experimenting. If making short films or docs you would use dual system audio anyway and that only makes the in-camera audio usable as a scratch track. If you want to shoot a "home video" and watch it with a real projector, then it would be fine. But otherwise pretty useless. Personally I would like to have a modified camera which can shoot normal film so that I would only have to pay once and then it could shoot all the available stocks without needing to source the one special film stock which is made single batch at a time crowdfunded and would be unavailable for years at a time.

it can vary case by case but in most situations the foreground lights need to be moved most often and if you have small g/e team then it can mean that the foreground lights need to be relatively small and lightweight. if having a bigger team, then you may have possibility to tweak it better and use larger/more difficult to handle gear for the foreground. I see it like this: background: stays mostly the same all the time. big lights which don't need to be moved often. large hmi or multiple smaller units can be possible because you need to build it once and then it stays relatively the same. foreground: this is where most of the action often happens and you need to tweak the lights shot by shot. the units need to be able to be moved quickly even with minimal crew. On smaller shoots this often means Led units, possibly battery powered midground: often you only need to add some accents unless some of the actors move a lot in this area. So if actors on the midground, then you need to light it... otherwise, only add what you absolutely have to. this way you save lots of time