[biz-engineer]

I used an A7r a few times and the results were so much better in low light

Well, if you use a 1 stop faster lens on a K-3, you get the same as FF (simply because the K-3 sensor come out of the same production line as the A7 sensor from Sony, but the K-3 sensor is roughly half the size).
In reality, the bottelneck is at ISO100 , FF achieves more slick images at ISO100 and the K-3 can't catch-up because the ISO can't be lowered below 100.

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Last edited by biz-engineer; 03-08-2015 at 09:34 AM.

[normhead]

Well, if you use a 1 stop faster lens on a K-3, you get the same as FF (simply because the K-3 sensor come out of the same production line as the A7 sensor from Sony, but the K-3 sensor is roughly half the size).
In reality, the bottelneck is at ISO100 , FF achieves more slick images at ISO100 and the K-3 can't catch-up because the ISO can't be lowered below 100.

I think you might need to define "more slick". It's not a term I recognize.... my point being that once you reach a certain level of "slickness" no further "slickness" is noticeable. For me, with my K-5 and K-3 cameras set from 100-400 ISO and sometimes as high as 1600 no additional "sllckness" is needed, or can even be appreciated.

My observation has always been, backed up by many charts and images, there's not a lot of difference between FF and APS-c images taken from 100-400 ISO. SO, you're actually discussing something that's really only an issue past 1600 ISO. And then if you match DoF you can shoot at wider ƒstop with APS-c, one stop faster ISO and completely negate the FF advantage.

[JimmyDranox]

If you want to see the bottleneck check this out. Sony A7 at left and Pentax K-3 at right, both at ISO 6400. From Imaging Resources.

[normhead]

Exactly what I was talking about, the K-3 image is unacceptable, but so is the Sony. For some of us un-acceptable is an absolute, there is no "more un-acceptable" and "less unacceptable". If I were you, I would have looked for the point where the Sony image was acceptable and the K-3 wasn't. Also you found images that don't show the K-3 DOF advantage. To normalize the DoF you should have compared a 6400 ISO A7 to a 3200 ISO K-3. The you'd have two images with the same DoF.

In images like this i's hard to get the whole bird in focus. Not taking into account the number of times maxing out your DoF is important to an image, is probably the biggest mistake FF proponents make. They talk about a noise advantage, that in this type of photography just doesn't exist.

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Last edited by normhead; 03-08-2015 at 10:17 AM.

[biz-engineer]

A7 @ 6400 vs K3 @ 1600.

[JimmyDranox]

Yes. At different iSO sony at 6400, and Pentax k-3 at 3200, the difference in noise is not so big. But still, The FF semms to have a bbetter resolution that APS-C, even if they are both 24Mp.

[biz-engineer]

The slightly better resolution of the A7 remains.

[JimmyDranox]

That's the reason for which I hope that Pentax FF will go for Quality=low light performance, not Quantity=a lot of Mp with a lot of noise. If they can match the low light performance of Canon 6D, would be great (I'm not dreaming of A7S performance, is something different, at 12 Mp).

[Eyewanders]

If you've shot weddings in the past with the K3 and your customers were satisfied, then there is no objective reason why you can't continue to shoot weddings for another 1/2 to 3/4 year with the same equipment or rent a FF for a couple of occasions.

If you want to change systems for other reasons, by all means do it.

Yes. This. What exactly is the "problem" here?
I never understand most threads like this. Leave the system... Don't leave the system... It's a button-pushing topic but there's just better things to talk and worry about.

[normhead]

The parameters I defined were 100 to 400 ISO, so I'm not sure why you keep going on about the 6400 ISO thing. It's unacceptable both cameras, in most circumstances 1600 ISO is un-acceptable in a Pentax. Why do you guys keep trying to impress me with stuff, I've already told you is unacceptable? ou do understand that tho matter what system you use, buy 6400 ISO you've lost 4 stops of Dynamic range, on anything accept maybe a Sony A7s which has unacceptably low dynamic range to start with?

[Dlanor Sekao]

There is one thing that hasn't been mentioned yet ?....how to put the fire out ?
Here is MY suggestion......send ME the $4000 and I will hold it for you. You will always be MY "Pentaxhero" if you do....lol

[Sliver-Surfer]

The parameters I defined were 100 to 400 ISO, so I'm not sure why you keep going on about the 6400 ISO thing. It's unacceptable both cameras, in most circumstances 1600 ISO is un-acceptable in a Pentax. Why do you guys keep trying to impress me with stuff, I've already told you is unacceptable? ou do understand that tho matter what system you use, buy 6400 ISO you've lost 4 stops of Dynamic range, on anything accept maybe a Sony A7s which has unacceptably low dynamic range to start with?

I would have no problems including a 6400iso from my A7 on an 8x10" print in a package for a client

[ElJamoquio]

Well, if you use a 1 stop faster lens on a K-3, you get the same as FF (simply because the K-3 sensor come out of the same production line as the A7 sensor from Sony, but the K-3 sensor is roughly half the size).
In reality, the bottelneck is at ISO100 , FF achieves more slick images at ISO100 and the K-3 can't catch-up because the ISO can't be lowered below 100.

At same DOF, the 'bottleneck' is ISO as you mention. For example, D810 can do ISO47. All else the same, APS-C would have to do ISO 20 to match.

Of course the IQ on both at those low ISO's is pretty good.


If you can manage smaller DOF (e.g. all shots at infinity, many shots in a church, but few shots in a dining room), you can really see an improvement with FF. E.g. if you're shooting outside, it's pretty easy to find an inexpensive 50mm F/1.4, but a 31mm F/1.8 is expensive, and on APS-C is over two stops slower.

Doesn't really count, but once I shot, handheld, a 14mm F/2.8 on FF, about an hour after official sunset. Looked pretty good to me, at least; for that one corner case.

---------- Post added 03-08-15 at 06:13 PM ----------

Yes. At different iSO sony at 6400, and Pentax k-3 at 3200, the difference in noise is not so big. But still, The FF semms to have a bbetter resolution that APS-C, even if they are both 24Mp.

Impossible. APS-C is way better. The lenses are so much cuter.

[JimmyDranox]

The parameters I defined were 100 to 400 ISO, so I'm not sure why you keep going on about the 6400 ISO thing. It's unacceptable both cameras, in most circumstances 1600 ISO is un-acceptable in a Pentax. Why do you guys keep trying to impress me with stuff, I've already told you is unacceptable? ou do understand that tho matter what system you use, buy 6400 ISO you've lost 4 stops of Dynamic range, on anything accept maybe a Sony A7s which has unacceptably low dynamic range to start with?

Because the member who started this thread want to make photos at weddings. And sometime (manytimes) at weddings low light performance is needed. And blinding the participants with the flash is not desirable.

[noser]

And then if you match DoF you can shoot at wider ƒstop with APS-c, one stop faster ISO and completely negate the FF advantage.

So if I change the ISO on my APS-C body, the 2nd SD slot on my FF body will disappear, it's OVF will dim and shrink, and the AoV/DoF optical ratio will change?

Yes, I'm being a jerk.