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02-29-2016, 03:44 AM   #61
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QuoteOriginally posted by D1N0 Quote
@chris mak the d800 sensor camera has the following specs:100 - 6400 in 1, 1/2 or 1/3 EV steps (50 - 25600 with boost) the a7r 100-25600. The k-1 100-204800. It is not the same sensor camera. Not with three extra stops iso. It is probably a new incarnation. So no the same as the d810 either.
Fixed

ISO range is not just a sensor property, its a camera property. Firmware contributes to how the sensor hardware are used. ISO range, step length and gain at every selected ISO level are some of the things that are programmed. For instance its no problem to enable silly high ISOs if they wanted. But that would be silly so why bother? If you really want it, just use the highest ISO and brighten it in post processing to get the same result. I'm not sure why they limited the ISO to 100 in the low end, but lower ISOs will fill the photodiodes "wells" with more electrons, increasing the voltage. I suspect that will increase the risk of pixels dying*.

* In extreme light cases the risk will increase. At night club or concert laser shows, lasers hitting camera sensor are proven to make sensors fail. The same problem are experienced by people using long tele lenses to photograph solar eclipses without a proper filter. Even if the shutter is open just 1/8000s it can cause single pixels or entire rows to fail. (The shutter may also deform and jam due to thermal expansion)

02-29-2016, 03:48 AM   #62
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QuoteOriginally posted by Chris Mak Quote
They simply have to.
Shooting at a higher iso settings essentially means only one thing: you shorten the exposure, as a result you have a weaker signal, and you have to apply a certain amount of gain to get to the desired brightness level.
You can also simply use a low iso setting and change the exposure time manually, and then in your raw converter bump up the exposure. The result won't be that much different. Shorter exposure time means a weaker signal and a darker image unless you apply gain to the signal.


It's a whole different story however, if you want to achieve a lower native iso that has a large dynamic range: here you do just the opposite, you increase the exposure time, and get a stronger signal. This will always decrease noise as you need less gain to get to the desired brightness of the image, but the sensor has to have the neccessary higlight headroom to allow for a lower native iso. If not, saturation in the highlights will occur and you will have clipping, loss of information. The ability to store photons is a part of the silicon design in a sensor and cannot be as far as I know, artificially stretched. That is why expanding the iso range to below the native iso of a sensor will not increase but decrease the dynamic range: you no longer increase DR by having a stronger signal and thus less noise, but you decrease DR by introducing saturation of the photon collecting wells.
Just check the behavior of sensors when iso is artificially expanded: the dynamic range in the highlights decreases. When however you check the D810 sensor setting at iso 64 (which is not an expanded iso), you will see that it tops the DR curve at that setting: it still has the neccessary highlight headroom, which will have to be designed into the sensor's silicon.
The K1 may well do better at high iso settings compared to equivalent 36mp sensors if Pentax controls the noise better in relation to applying gain to the weaker source signal. But it would surprise me a lot if they can reach the Nikon D810's DR of 14.7 ev at iso 64.
That's a very clear explanation - whatever results the K-1 sensor might or might not achieve, it's still valuable for those of us who don't/ didn't know much about the way it actually works - thanks!
02-29-2016, 04:38 AM   #63
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QuoteOriginally posted by D1N0 Quote
I don't think Ricoh would do that. It would get very crappy. They want to deliver, not bullshit.
QuoteOriginally posted by jbinpg Quote
This link posted by rawr yesterday has a paragraph on K-1 sensor ISO specifics. It appears the K-1 does not amplify the signal digitally to achieve higher ISOs. The English translation is less than perfect but it is chock full of nuggets:

?????????????????????????????????PENTAX K-1 ????????????? - ??????????by????????
All manufacturers must apply digital gain. Thats the way sensors work. There might be a small analogue gain too, but thats very limited. I think the main difference between Canon sensors and the rest is that Canon uses quite a lot of analogue gain for the lower ISO values (3-4 steps) to reduce the bit depth of the A/D converter. The purpose being making the A/D process both faster and more power efficient. Other brands use no or very little analogue gain (0-1 stop). Thats the main reason for Canons poor DR at low ISOs. Thats the trade of they did for combining readout speed with power efficiency. Canons DR are quite good at middle and high ISOs where digital gain is applied too.

BTW, I saw this image in the link:


Does this mean that it got movie SR?

Last edited by Simen1; 02-29-2016 at 04:44 AM.
02-29-2016, 04:50 AM   #64
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just a pity for the disinterest of third party manufacturers......

02-29-2016, 04:50 AM   #65
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QuoteOriginally posted by Simen1 Quote


Does this mean that it got movie SR?
It would be electronic not mechanical. 😯
02-29-2016, 04:51 AM   #66
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QuoteOriginally posted by Simen1 Quote
Does this mean that it got movie SR?
Sort of, it's digital SR.
02-29-2016, 05:08 AM   #67
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QuoteOriginally posted by JPT Quote
Digitalis - I can't find an English version of the new lens catalogue. Actually, I can't remember ever seeing an English version of the old one. Is this just a Japan thing? They are normally available in all stores that stock Pentax, along with the camera catalogues.

I can't see an English version of the K-1 catalogue, but the same information is available in English on these product pages.
There was an English printed catalogue back in the K20D days. I had one photocopied at the local distro in Manila. The DA*s were fairly new that time. After that though, I never saw another one in English.
02-29-2016, 05:13 AM   #68
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QuoteOriginally posted by Simen1 Quote
All manufacturers must apply digital gain. Thats the way sensors work.
That does not mean they will stretch it far beyond the specified range of the sensor without at least some tweaks. Otherwise everything beyond 51200 would be useless. There is a reason for extended iso ranges. Use at your own risk and do not complain about IQ.

02-29-2016, 05:20 AM   #69
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QuoteOriginally posted by JPT Quote
- At Sigma, I tried to ask how they decide whether to release lenses in K-mount, and pointed out that they had released the 35mm f1.4 in K-mount while Pentax had a number of 35mm lenses, but they haven’t released the wide angles that are missing in the Pentax line-up. The rep I spoke to just said that there were no immediate plans to release the new lenses in K-mount. On the subject of the 50-100 f1.8, I tried that out on a Sigma SD1 DSLR. It is huge, but not quite as heavy as I’d feared. The focusing was horrible, but I’m not sure if that’s a lens thing or the body. I was left rather unimpressed with the fast zooms. They don’t actually zoom much, so they seem to me like an awkward compromise between the convenience of a zoom and the quality of a prime.
That is my impression too (I have the 18-35/1,8). The zooming adds quite a lot of size and weight compared to primes. I also generally consider f/2,8 zooms to have the same problem. So I made a strategy for myself a couple of years ago, that I will carry one camera with a lightweight small aperture superzoom, and have a selection of good lightweight primes in the bag to pick up If I have the seconds to do so. The Sigma 18-35/1,8 are currently being considered as one of those primes, but I should probably exchange that for a true prime.
02-29-2016, 05:23 AM   #70
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QuoteOriginally posted by christiandre Quote
just a pity for the disinterest of third party manufacturers......
Interest is the core of any business, and it shall come (or not) once K-1's success will be confirmed.
As Ricoh's rep. has aknowledged, Ricoh didn't spend time to push third parties K-mount lens production.
It never was their priority, and it is easily understandable.
But if Sigma for example sees business opportunities in the K mount, because of higher sales in K-1 and/or K-3II/K-S2/..., things will change.
K-1 in itself could push up Pentax DSLR sales, being considered as a real flagship by Pentax customers or newbees, and stop part of the past bleed for the reason there was no K-mount offer in FF.
But of course, time will tell.
Imho, we could see 1 to 3 new Sigma lenses made available in K-mount by the end of this year.

Last edited by Zygonyx; 02-29-2016 at 05:33 AM.
02-29-2016, 05:33 AM   #71
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QuoteOriginally posted by D1N0 Quote
That does not mean they will stretch it far beyond the specified range of the sensor without at least some tweaks. Otherwise everything beyond 51200 would be useless. There is a reason for extended iso ranges. Use at your own risk and do not complain about IQ.
I don’t think It a manufacturer specified range, but a manufacturer recommended range, where the lower limit are more important then the upper. Increasing the ISO in whole steps is just a (electronically and energy efficiency speaking) extremely easy bit shift, probably done in the sensor. I don't see any reason for the manufacturer to define a upper limit. Its not like their brand reputation is at stake. Pentax, Nikon and others using Sony manufactured sensors don’t use the Sony brand name anywhere. The level of highest ISO crappiness is only affecting the reputation of the camera brand. Both positive and negative. Nikon actually got a lot of positive feedback when they increased the ISO silliness to new levels recently.

Last edited by Simen1; 02-29-2016 at 05:41 AM.
02-29-2016, 06:03 AM   #72
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QuoteOriginally posted by derekkite Quote
Reading the translated link seemed to indicate that the gain is applied before tha a/d conversion as opposed to applying it to the digital data. Not sure if that is any different to what has been done elsewhere. It will be interesting to see how well it works.
Sony sensors have the A/D conversion done on the sensor and have done this since at least the K-5 sensor. Some gain and NR has always been applied prior to the A/D conversion. This is one reason why Sony sensors started to outperform Canon sensors.
02-29-2016, 06:04 AM - 1 Like   #73
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QuoteOriginally posted by Zygonyx Quote
As Ricoh's rep. has aknowledged, Ricoh didn't spend time to push third parties K-mount lens production.
It never was their priority, and it is easily understandable.
I keep wondering, how do the people asking such questions envision Ricoh pushing third parties to release K-mount lenses. Pay the 3rd-party makers? As in: pay the 3rd-party makers to make the lenses, but the profits would go to the 3rd-party makers? (at the expense of Ricoh) Be very convincing, i.e. than whatever factors they're basing their decisions on?
Technically speaking, 3rd-party makers already demonstrated their capability of making K-mount lenses, so that's not what it holds them back.
02-29-2016, 06:13 AM   #74
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QuoteOriginally posted by Simen1 Quote
All manufacturers must apply digital gain. Thats the way sensors work. There might be a small analogue gain too, but thats very limited. I think the main difference between Canon sensors and the rest is that Canon uses quite a lot of analogue gain for the lower ISO values (3-4 steps) to reduce the bit depth of the A/D converter. The purpose being making the A/D process both faster and more power efficient. Other brands use no or very little analogue gain (0-1 stop). Thats the main reason for Canons poor DR at low ISOs. Thats the trade of they did for combining readout speed with power efficiency. Canons DR are quite good at middle and high ISOs where digital gain is applied too.

BTW, I saw this image in the link:


Does this mean that it got movie SR?
Would be nice if the "spot" position could be adressing any other "USER" choosen feature...
02-29-2016, 06:22 AM   #75
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I found something interesting in regards to AF and ISO of the K-1:

In this video below, this Taiwanese reviewer mounted the 15-30, 24-70 and 70-200 on the K-1 and tried it's AF performance in live view, it actually focuses reasonably fast, and it seem to have face detection too( you can also hear the shutter sound in this video too):

This Chinese reviewer shot the K-1 in from ISO 6400 to ISO 204800, SD card is not allowed to be put in so he showed those images from back of the camera screen. Those pictures seem very encouraging in turns of ISO performance, however not sure what the image format those are and not sure noise reduction is turned on or not:
CP+2016:

If any of you interested what the guy in the video actually says or what the article says, happy to help.
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