[Digitalis]

The ionisation could be via [crudely] a spark plug. Then magnets to stimulate and steer the airflow.

Incidentally: Ionization is an electrostatic effect not a magnetic one. A magnet will not repel charged particles, but it will deflect them. And strong electrostatic charges are well known for utterly destroying sensitive electronics.

I Would use peltier effect cooling ( as energy inefficient as it is) It is compact and reasonably efficient for cooling....but there would still be the problem of removing the heat from wherever the peltier effect cooler dumps it.

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Last edited by Digitalis; 02-23-2016 at 09:17 AM.

[Kunzite]

I think a microwave generator would be a more efficient way of generating heat. That's what you're trying to do with all those powerful electromagnets and "spark plugs", right?

[rawr]

Sure, every 2 min the rubber sphincters would open up and PFFFRRRTTT release the warm gasses right in the photographer's face, but its a technology worth pursuing

Excellent idea!
Such rubber sphincters would be great in Pentax marketing literature. Probably help the camera sell very well in the same markets where glass coffee tables also apparently sell well.

[D1N0]

Air has terrible thermal conductivity. to be effective at all Air needs a way to escape for convective cooling, how would you implement that in a weather sealed camera body?

My point was that sr doesn't do much to generate extra heat, it would sooner cool down the sensor. Unless there is a heat sink applied in sr=off mode, heat cannot be the reason why sr is turned of in video. And even if it is you could still get a few minutes of video with it on, so we should have a choice. We don't so I think there is another reason. Likely a stupid one.

[Digitalis]

sell very well in the same markets where glass coffee tables also apparently sell well

Garçon! a chilled glass of brain bleach with a side order of strychnine please!

[Simen1]

You would not want ionized air inside the camera! Please, that discussion is way off anything useful.

A similar concept to a heat pipe - however you're still faced with the problem of removing the heat from the system. And as I recall, heat pipes can only operate under finely tuned temperatures - at temperatures above or below their operating temp, thermal conductivity is limited to that of the casing itself, the heat transmitting fluid within is either completely vaporized from heat or solidified from excessive cold.

I Would use peltier effect cooling ( as energy inefficient as it is) It is compact and reasonably efficient for cooling....but there would still be the problem of removing the heat from wherever the peltier effect cooler dumps it.

Magnesium conducts quite well and in this case it has a large surface area. You could approximate that is has an evenly distributed ambient temperature. That means you only need to transport the heat from the sensor to the magnesium chassi.

I like the peltiér idea even if it would drain the battery very fast. But since we need some flexibility to make the SR work I think other cooling solutions eater have to assist the peltiér, or just replace it. Heat pipes are quite good within its temperature range. It would be limited upwards by vapour condensation temperature and camera chassi temperature. For combined liquids (water, ethanol, metanol, ammonia) the condensation temperature is a range, not a single temperature like for pure liquids. As an example, when destilling water-etanol solutions the vapourisation and condensation temperatures range between 78 and 100 degrees C. They adjust the range by adjusting the mixture and pressure.

That said, I also like my own idea of a micro fridge. Vapor-compression refrigeration is quite energy efficient, can be miniaturized and can use quite flexible pipes. A micro fridge could remove the heat from the sensor or peltiér to the chassi.

I also found a couple of other cooling technologies I don't know much about:
https://en.wikipedia.org/wiki/Vortex_tube
https://en.wikipedia.org/wiki/Thermoacoustic_heat_engine

[rawr]

https://en.wikipedia.org/wiki/Thermoacoustic_heat_engine

Wow. I always thought bass players were pretty cool dudes. Now I know why. [Doesn't explain drummers though].

[monochrome]

Hello Jack. Can we get this thread back on topic?

[filoxophy]

Here's your sensor cooling solution:

Telescopes.net - sku# PLL700DA | Primaluce Labs - Canon EOS 700Da Cooled DSLR Camera - sku# PLL700DA | Woodland Hills

[D1N0]

In the back of the K-1 there are two holes (they are stopped up for weather sealing) but you could remove the stops and attach a closed air cooling system (closed against blowing dust in the camera )

[Simen1]

If the three holes really lead into the sensor area, and don't cause sensor vibrations (that are not picked up by the gyros) its a great idea, but I doubt it leading all the way in.

A closed loop system with an external cooler will also work as a freeze dryer, so no risk for condensation.

[phoebus]

I can really see the sensor shift coping really well with a refrigerant tank attached, containing a variable mass of liquid/vapour sloshing about in it - NOT...

I think the heat pipe thing is more relevant to the microprocessor cooling.

;-)

[ffking]

I think Pentax are currently developing a FF camera with 4K video, high fps full HD and faster burst shooting, to be released later, maybe late this year or in 2017. I guess they just did a tactical switch of witch camera to release first

sorry about the whiplash damage of responding to a post several pages back -I just wanted to say that right or wrong it's quite a plausible thesis in terms of known facts - but the truth is that there is divergence in the market now - you can't have a single camera- even within the restrictions of it being, say a FF DSLR - that does it all. You can't change sensors like you changed films, so you do really need specialisation at an advanced/pro level - cameras for high IQ and cameras for fast burst rate. Video sits more comfortably with the second, and if Pentax effectively made a 'field camera' and an Action camera - equal level but largely different markets - I'd be happy to stick with the K1 and its successors.

[Nicolas06]

sorry about the whiplash damage of responding to a post several pages back -I just wanted to say that right or wrong it's quite a plausible thesis in terms of known facts - but the truth is that there is divergence in the market now - you can have a single camera- even within the restrictions of it being, say a FF DSLR - that does it all. You can't change sensors like you changed films, so you do really need specialisation at an advanced/pro level - cameras for high IQ and cameras for fast burst rate. Video sits more comfortably with the second, and if Pentax effectively made a 'field camera' and an Action camera - equal level but largely different markets - I'd be happy to stick with the K1 and its successors.

Could be, but as we progress, I think you'll have equivalent of K3/D7200 bodies on FF that will have everything. Fast burst, max res availale on the format etc.

[WPRESTO]

Please excuse if this question has been asked and answered earlier and I missed it. When mounting an APS-C only lens and using crop mode, what do you see through the viewfinder? Are there permanently etched lines for framing, or bright, projected frame lines that only appear in crop mode, or is the ground glass partially blocked by shields as during the silly panoramic mode fad? What about Live View, what appears on the screen? Is the APS-C framing enlarged to fill the screen?