I looked at the PointGrey range at the end of last year, and was very impressed with the specifications using the Sony chips. But the cheapest model I could find to satisfy my perceived requirements at the time (I have since relaxed these) was about $1000, so I reluctantly dismissed them. However, having said that, I thought their range of cameras were very good value compared with their competitors.
Your mention of the Blackfly prompted me to go back and look again at their range, and I agree that they have several models that are much more affordable (I don't know why I missed these), and may tempt me to invest in one if I decide to persevere with continuous motion, which I think is looking less likely with the MC500 unless running very slowly (< 3fps).
Selecting a suitable camera is not an easy task, given the variables associated with different aspects of Kinograph like frame rates, film gauge, sensor resolution, and flash settings, and their influence on 'pixel smearing' due to continuous motion. Up until now I have done laborious calculations at each iteration in an attempt to match these variables against affordable camera specifications. Basically, the process was not that fruitful, being too slow, open to occasional human errors, and failed to converge on a definitive answer. So this weekend I entered my equations into a spreadsheet shown here -
The result has been very enlightening, producing answers that were most unexpected, such as the film gauge having very little effect on the temporal demands of the image sensor. It is also very easy to see how the frame rate can be optimised for any particular sensor that has a global shutter, or the duration of flash illumination for those that do not, giving regard to a particular 'pixel smearing' performance that is considered acceptable.
I have also been able to investigate something that I have been considering for a while - turning the sensor through 90 degrees to make greater use of its pixel real-estate. This is what I mean -
Correcting it on capture is trivial, requiring no processing - the horizontal and vertical axes are just swapped using an option available in many capture programs, along with mirroring.
All the examples I give above are set for the MC500, but any sensor characteristic can be entered into the spreadsheet. (The yellow boxes are those used to enter information, all others are locked as they contain the equations which can be read but not edited inadvertently. Users can unlock everything if they wish, but at their own peril.
I only finished the sheet a few hours ago and am still gaining confidence in the results, but when I am happy with it I will make it available to anyone that requests it.
Not really, because there is plenty of time to make several captures during the static period of the claw(s), unless attempting to operate at full frame rate which is not advisable.
This depends on how the performance is assessed. If comparing numerical specification values, then the turning point may be much higher than the MC500. However, if it is based on the subjective quality observed on (say) a 32" HD TV, then this could bring it a lot closer to something like the MC500 or even a webcam. For example, comparing two sensors with a 20dB (10x) difference in S/N ratio may look very similar on such a TV screen viewed at a sensible distance. The same goes for shadow and highlight detail, colour accuracy, contrast ratio, etc, etc. I will be viewing my own captures on a 65" Samsung 4K curved TV, which will be about as demanding as I would have thought reasonable. I still have to make this judgement however, as I am more interested at the moment in getting the transport and control aspects completed to my satisfaction.
Yes, I used to get this with my Canon Hi8 camera in the '90s, which used a CCD chip, but I haven't noticed it in more recent times, even when videoing in 1080p with my Lumix compact camera.
OK, I'll give it a try. Do you use opaque or transparent filament? What wall thickness do you use?
Here is the lens assembly that I am currently using, which I created to fit on a modified Eumig P26 projector. Note - the legends are incorrect, I mixed up the M42 and M49 references.
There are two sliding adjustment tubes, one fits in the projector lens holder, and the other slides over the MC500 microscope eyepiece adapter. Both affect focus, but the MC500 end has the strongest effect on magnification. It sounds awkward to set-up, but really is not that bad. Once focus and magnification are adjusted satisfactorily, they are locked and rarely need to be altered. The lens focus ring has a small effect, but I normally leave it on infinity.
OK, but this could affect 'pixel smearing' as my spreadsheet shows. A better method may be to use high frequency PWM, gated to the required flash duration?
Not really necessary, because the PLL(s) in my design act like a flywheel to overcome this problem. Moreover, the camera is triggered by the stable pulse generator, not directly from the sprocket hole sensor. In the future I will add an orthogonal sensor to the sprocket holes on the other side of the gate to servo the vertical position of the camera to compensate for vertical drift in the film, thus removing the need to contact the film edges with static guides which could further damage impaired sprocket holes or torn edges.
There will be no likelihood of any sparks - my thoughts are in using ion streams like those used in vinyl record cleaners to do the job, coupled with micro-fine carbon brushes to neutralise local static charges. Peter's suggestion of adding a PTR roller may also be a good one to remove any remaining foreign bodies because there is unlikely to be any static charge left to attract them.