[jatrax]

The numeric score DxOMark assigns to a camera "is the highest ISO setting for a camera that allows it to achieve an SNR of 30dB while keeping a good dynamic range of 9 EVs and a color depth of 18bits" - in other words, the highest ISO a camera can go whilst still delivering excellent image quality. So the K-3, according to DxOMark, can meet this criteria at ISO 1216, but the Nikon D610 can do it at ISO 2925. The DxOMark low-light scores feel about right for the cameras I have experience with.

So if I understand this right, if I am happy with a K-3 image @ 1200 ISO, the image quality from a like image taken with a Sony A7 @ 3700 would be about the same? In other words a little more than 1 stop advantage?

[rawr]

In other words a little more than 1 stop advantage?

Sounds about right. They say a difference in low-light ISO of 25% represents 1/3 EV.

And it's the A7s that gets the cool 3700 ISO score. The normal A7 only scores a mere 2248 ISO

[calsan]

So if I understand this right, if I am happy with a K-3 image @ 1200 ISO, the image quality from a like image taken with a Sony A7 @ 3700 would be about the same? In other words a little more than 1 stop advantage?

For me, that advantage sounds theoretical, except in one specific situation: When you are happy to shoot wide open at normal focal lengths - so ironically, for subjects that are stationary, like portraits.

[jsherman999]

For me, that advantage sounds theoretical, except in one specific situation: When you are happy to shoot wide open at normal focal lengths - so ironically, for subjects that are stationary, like portraits.

Why would that restriction be in place for you? Consider, shooting a moving subject like a toddler:

K3: 50mm f/2.8 1/50s ISO1200
A7s: 35mm f/4 1/100s ISO 3600

Say the first combo gives you good noise performance, but you'd like the shutter speed to be a bit higher to combat blur - the second (A7s) combo gives you that higher shutter speed with about the same noise and DOF.

Also, I shoot wide-open at normal focal lengths all the time - with fast & accurate AF, it works very well and the lack of DOF isn't an issue - or is a positive.

[jatrax]

Sounds about right. They say a difference in low-light ISO of 25% represents 1/3 EV. And it's the A7s that gets the cool 3700 ISO score. The normal A7 only scores a mere 2248 ISO

Thanks for the explanation! I've seen those claims many times but for some reason it just did not sink in properly.

But the Sony sensor in the A7 is a newer generation than the one in the k-3, right? If so we are not comparing apples - apples. What would be the FF sensor from the same generation as the k-3?

[rawr]

What would be the FF sensor from the same generation as the k-3?

The A7 and the K-3 were released at about the same time in 2013 (October 2013). So they are probably both of the same generation, as it were.

However the 24MP Nikon D610 FF was also released in October 2013, again likely with a Sony sensor. Yet the D610 scores 2925 compared to 2248 for the A7, it's nearest direct FF contemporary. So it's hard to make 'apples - apples' comparisons between FF sensors of the same age, let alone between FF and APS-C.

[Paul MaudDib]

When we already see threads like "How to get the FF out earlier " and stuff on the new posts page all the time, when every thread gets turned into a "we want an FF thread".. I see the thread, "Dear Pentax: Never Build a "Full Frame" Camera", is a refreshing thought. I have heard so many reasons why people have to have Full Frame cameras, I'm sick of it. With the release of the A7r there is now an FF for your A glass, or any glass that you can manually focus, A very good FF. But now we have folks whining... it has to be a Pentax.

Well, you have what you want, you won't buy it. When are you ever going to stop complaining about this?
Buy your FF, start posting pictures in the Pentax glass on other cameras, stop wasting your time wishing Pentax would do what you want.
Quit crying in your beer feeling sorry for your pathetic selves and get on with your lives. Pentax not making an FF isn't a real problem for anyone.

Hahahahahahahahah.

This Fox has a longing for grapes:
He jumps, but the bunch still escapes.
So he goes away sour;
And, 'tis said, to this hour
Declares that he's no taste for grapes

I mean I'm not gonna disagree with you that there's greener pastures to be had elsewhere. But "hey guys why don't you buy someone else's products" is not exactly a good marketing pitch for Pentax's products.

And on the remote chance that Pentax actually does release a FF, these posts are going to be hilarious to read as you all line up to fork over your cash for a full frame.

[dadipentak]

But "hey guys why don't you buy someone else's products" is not exactly a good marketing pitch for Pentax's products.

I don't think Norm is affiliated with the Ricoh marketing department. ;~)

[normhead]

I don't think Norm is affiliated with the Ricoh marketing department. ;~)

Although I'm pretty cheap to hire, hell just throw me a 645z and a couple of lenses and I'm your boy, Ricoh.
If Benjikan lost his sponsorship deal, what hope do any of the rest of us have of ever getting 10 cents for promoting Ricoh? All it gets us is grief from those with different photographic preferences shooting other brands, and god knows there re lots of those.
My brand loyalty is extremely suspect.. though I've often been accused of being a Pentax freak. Make something I can use, and it goes with what I've got, and I'll probably buy it. If I can get away with buying it. The House Appropriations Committee has had a stern expression of late.

[GordonZA]

For those wanting a really nice affordable FF have a look at the new Nikon D750, for those wanting an awesome APSC have a look at the specs of the new Canon 7D mark Ii... Looks like the super high speed train has left the station and Ricoh is still at the ticket office trying to buy tickets for the 70s disco.... K-S1 anyone....

[easyreeder]

Canon 7D mark Ii

Or the Samsung NX1, or the Sony E mount, many cameras. Has nobody noted that as of this Photokina it looks like Sony is backing off the A mount in favor of the E mount? Kind of big news, no? Given how much the K mount shares with the A mount.

[calsan]

K3: 50mm f/2.8 1/50s ISO1200
A7s: 35mm f/4 1/100s ISO 3600

I don't understand this scenario.

[Rondec]

Why would that restriction be in place for you? Consider, shooting a moving subject like a toddler:

K3: 50mm f/2.8 1/50s ISO1200
A7s: 35mm f/4 1/100s ISO 3600

Say the first combo gives you good noise performance, but you'd like the shutter speed to be a bit higher to combat blur - the second (A7s) combo gives you that higher shutter speed with about the same noise and DOF.

Also, I shoot wide-open at normal focal lengths all the time - with fast & accurate AF, it works very well and the lack of DOF isn't an issue - or is a positive.

The weird thing to me, Jay, is if I look at the curves for dynamic range and SNR for the A7s and K3, what I see is that there is a stop difference in SNR at basically all isos. At iso 3200, there is a 1.5 LV difference between the cameras. At most, I see two stops of difference between these two cameras, not any three stops as you indicate in your comparison.

I understand that the DXO Mark sports isos are 1200 and 3700 respectively, but I don't see where those numbers come from based on the graphs.

[monochrome]

My likely unpopular Post.

PENTAX WILL NEVER MAKE A FF DSLR LESS THAN 36mp. Not their strategy... IF AT ALL...

a FF MILC? Absolutely, with an EVF better than competitors. K-Mount.... 18 mos out...Probably 36MP. When everybody else has them In DSLR. No need for a DSLR. Next DSLR? 32-36MP APSC. More points in AF, bigger buffer. After an ultra wide DA*/Pro is out. 15-18mos. FF continues to shrink.

9 months.

D810 competitor or fast (dual processor, dual bus, from 645Z) MILC. Don't be sellin' your good lenses just yet.



*Surprise!

[Rondec]

9 months.

D810 competitor or fast (dual processor, dual bus, from 645Z) MILC. Don't be sellin' your good lenses just yet.


*Surprise!

Maybe you're right. I am sure Pentax is working on something. I just hate when people pump up forumites about the future. The roller coaster of elation, followed by depression, followed by anger is kind of hard to watch. I'm pretty satisfied with my gear right now and am happy taking photos with it, which lets me pass the time fine until such time as there is newer and better gear from Pentax.

Some folks are more like Robinson Crusoe on the island, scratching marks on a post for every day there is no Pentax full frame camera.