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Forum: General Photography 10-12-2017, 03:49 PM  
Does IBIS affect precise focusing and exposure metering?
Posted By dtmateojr
Replies: 44
Views: 2,121
IBIS does affect focusing to some extent. Had this issue with my K5. The focus issues happen at higher shutter speeds between 125-320. Possibly because IBIS kicks in when it is not needed. Much like having IBIS turned on when you are on a tripod and the image becomes blurry.

Edit: lens is sigma 17-70
Forum: General Photography 11-02-2016, 05:20 AM  
No more "Travel Photography" or "Photo Safaris" for me...
Posted By dtmateojr
Replies: 71
Views: 4,670
It's a cycle. You hate your shots because they look like a million other shots but then the reason you went to a particular spot was most likely because you saw the other million other shots. So it's like shooting yourself in the foot.

Go somewhere else that is totally unfamiliar to you and try to make a shot that is worth posting on your wall. You'll learn how to see and not just copy.
Forum: General Photography 07-15-2016, 06:16 AM  
Technical vs. technique
Posted By dtmateojr
Replies: 65
Views: 3,636
Forum: Pentax Full Frame 07-07-2016, 03:25 AM  
24mp full frame K mount camera, possible?
Posted By dtmateojr
Replies: 193
Views: 9,356
The lower res alternative already existed when Pentax released the near-perfect K5II. Just buy that instead. It's the same sensor as the K1
Forum: Pentax Full Frame 03-20-2016, 06:37 AM  
K-1 So What Is Full Frame Going To Provide Over A Crop Frame DSLR
Posted By dtmateojr
Replies: 312
Views: 18,388
Keep believing that lol! Equivalence will not change facts. :)

moving_comfort wrote:

Correct? Print tab accounts for total light differences (not just MP differences) and gives an accurate comparison of output from different sensor sizes?
I don't know what total light or its units are but the print tab simply puts all sensors on a level playing field by assuming all images are resized to 8MP. So the D7k 'screen' values would be adjusted by sqrt(16/8) and the D800's by sqrt(36/8) to become 'print'.

Jack
Forum: General Photography 03-20-2016, 06:12 AM  
What do you think will happen to APS-C over the next 10 years?
Posted By dtmateojr
Replies: 111
Views: 4,492
Rx
Forum: Pentax Full Frame 03-20-2016, 02:45 AM  
K-1 So What Is Full Frame Going To Provide Over A Crop Frame DSLR
Posted By dtmateojr
Replies: 312
Views: 18,388
Jack Hogan of DPR has seen the light

Forum: General Photography 03-20-2016, 02:34 AM  
What do you think will happen to APS-C over the next 10 years?
Posted By dtmateojr
Replies: 111
Views: 4,492
True, so how come you still got it wrong? Can't type?

---------- Post added 03-20-16 at 19:42 ----------

Jack has seen the light :-)
Forum: Pentax Full Frame 03-20-2016, 02:32 AM  
K-1 So What Is Full Frame Going To Provide Over A Crop Frame DSLR
Posted By dtmateojr
Replies: 312
Views: 18,388
What?!!! Your calculations for IMAGE size was not image size. You were calculating for SENSOR size (sensel pitch x num of pixels). Duh?! Sensor size is NOT equal to image size. Fact.



I NEVER said that. I never mentioned total light. You equivalence fu proponents should stop using that total light crap.

I said K5 and D800 have same SNR and dxomark SCREEN snr is PROOF of that.





FFS, I never said they capture the same total light. Learn to read.
Forum: Pentax Full Frame 03-19-2016, 08:44 PM  
K-1 So What Is Full Frame Going To Provide Over A Crop Frame DSLR
Posted By dtmateojr
Replies: 312
Views: 18,388
...and we have someone who understands.
Forum: Pentax Full Frame 03-19-2016, 07:46 PM  
K-1 So What Is Full Frame Going To Provide Over A Crop Frame DSLR
Posted By dtmateojr
Replies: 312
Views: 18,388
ROFL! Image size is horizontal pixels multiplied by vertical pixels. Nothing more. Don't overanalyse. You really are too funny.





Err....wrong again. So you don't understand image size and you don't understand sampling as well. What do you understand?






QuoteQuote:




---------- Post added 03-19-2016 at 07:30 PM ----------









https://dtmateojr.wordpress.com/2014/06/10/debunking-the-myth-of-full-frame-superiority-part-2/



Sounds to me like he agrees with the Bustard




Yes, he is one of the brainwashed by Bustard. So far he is now realising that PRINT snr has got nothing to do with sensor size and now somebody wants him (whoever that cainn guy is) to shoot himself in the foot by saying that sensor size does matter with total disregard for a proper explanation. Jack can't escape here. He will have to shoot himself in foot if he wants to remain brainwashed. What a bunch of clowns.
Forum: Pentax Full Frame 03-19-2016, 06:48 PM  
K-1 So What Is Full Frame Going To Provide Over A Crop Frame DSLR
Posted By dtmateojr
Replies: 312
Views: 18,388
Wow. What a low life.
Please ignore me. I don't want you to learn something. Go to DPR instead. Lots of idiots there.
Forum: Pentax Full Frame 03-19-2016, 06:25 PM  
K-1 So What Is Full Frame Going To Provide Over A Crop Frame DSLR
Posted By dtmateojr
Replies: 312
Views: 18,388
Yes, because the EM5 has the same SNR as the 5DS. Different story if it was vs a D800 but you will quote me totally out of context just to make me look stupid.

Keep on dreaming while others here have seen the light.
Forum: General Photography 03-19-2016, 04:01 PM  
What do you think will happen to APS-C over the next 10 years?
Posted By dtmateojr
Replies: 111
Views: 4,492
Did you calculate it? Because the second term drops to zero for N1=N2. Read my blog if you are not scared of the truth.

---------- Post added 03-20-16 at 09:02 ----------




Wrong! SNR is SCREEN snr NOT print snr. Read my blog.
Forum: General Photography 03-19-2016, 03:26 PM  
What do you think will happen to APS-C over the next 10 years?
Posted By dtmateojr
Replies: 111
Views: 4,492
Nope. You can do the math yourself:

nSNR = SNR + 20 x log10(sqrt(N1/N2))

N1 is the sensor image size and N2 is the chosen print size. You can get N1 from the SCREEN snr.

At N2 = 16Mp or higher, the D4 beats the D800.

And you can read about that here

https://dtmateojr.wordpress.com/2014/05/19/megapixel-hallucinations/

Cue in the admins that would flag me again for posting a link to my blog. They would rather that I post a very long reply here than point a link to a more detailed explanation. So click on that link before a trigger happy admin deletes it.
Forum: Pentax Full Frame 03-19-2016, 03:17 PM  
K-1 So What Is Full Frame Going To Provide Over A Crop Frame DSLR
Posted By dtmateojr
Replies: 312
Views: 18,388
OMG?! ROFL!!!

See, this is why I didn't want to answer your question because it is so obvious! Of course 16Mp is the same IMAGE SIZE as any other 16Mp REGARDLESS of sensor size. But, dude, they are NOT the same resolution. A 16Mp APS-C or m43 has MORE resolving power than a 16Mp FF sensor.

See if you can figure that out. I'm literally laughing my a## out as I'm typing this.

---------- Post added 03-20-16 at 08:45 ----------

For the DPReview fans, follow this new thread http://www.dpreview.com/forums/post/57461505

The truth will come out and it will be a big slap in the face for Joseph James (aka Great Bustard) and his minions of equivalence proponents. So far only Jack Hogan is making sense in that thread. The rest just can't accept Jack's responses yet. They are probably trying to internalise the implications: that equivalence is very wrong.

Big grin :-D
Forum: Pentax Full Frame 03-19-2016, 02:13 PM  
K-1 So What Is Full Frame Going To Provide Over A Crop Frame DSLR
Posted By dtmateojr
Replies: 312
Views: 18,388
Worse case, you could always upsize an image in the computer before printing. You won't gain details but it will prevent pixelation.
Forum: General Photography 03-19-2016, 02:09 PM  
What do you think will happen to APS-C over the next 10 years?
Posted By dtmateojr
Replies: 111
Views: 4,492
I think you missed the whole post or maybe I'm not understanding you.

What I was saying is that printing a FF 36Mp at 8x10 is not a measure of its real performance. A 16Mp APS-C at 8x10 is not a measure of real performance. It just so happened that 8x10 is a standard that has been chosen by dxomark and it is a fact that this arbitrary standard favours higher megapixels. 8x10, mind you, is also used for certain calculations other than SNR. Circle of confusion, for example, which dictates depth of field is also based on a 8x10 print viewed from a distance of 10".

If for example they normalised at something larger than 8x10 (8Mp), say, at 16Mp, then the PRINT snr graphs of the D4 vs D800 will change dramatically because they would no longer be equal. The D4 will come out on top. So in this case alone we could already see the unintended bias resulting from that arbitrary choice of standard.

And then there's the human factor. As per my own experience, a 85" 4K tv (8Mp) looks very good at a distance of 1.5m. Which means that anything larger than 8Mp printed at 85" will probably not make any difference. You might notice something different if they were put side by side but on their own then would pass image quality requirements. So using PRINT snr as basis for sensor performance is not a good indicator, especially not with a tiny 8x10.
Forum: Non-Pentax Cameras: Canon, Nikon, etc. 03-19-2016, 01:49 PM  
The Phone Club!
Posted By dtmateojr
Replies: 731
Views: 58,615
This guy can shoot. Really nice set here. #4 for me.
Forum: General Photography 03-19-2016, 01:46 PM  
What do you think will happen to APS-C over the next 10 years?
Posted By dtmateojr
Replies: 111
Views: 4,492
That's one way of looking at it. The apparent doubling of focal lengths going from m43 to ff is too much. You lose a lot on the wide end. m43 is good for those instances when you need something small to bring wherever you go without sacrificing image quality. It's the mobile camera for photographers. It's not meant to be a replacement for FF but if you are not invested in camera gear yet then m43 is a very good option and you won't really gain much by going bigger.

Then again, who doesn't want to go bigger? Liking something is reason enough to buy it. If I didn't have too many cameras I would want to try the K1 too, not because it will make better photos but simply because it's a really good piece of hardware. That thing is more usable than the Nikon and Canon counterparts. CaNikon users don't know what they are missing.
Forum: Pentax Full Frame 03-19-2016, 01:09 PM  
K-1 So What Is Full Frame Going To Provide Over A Crop Frame DSLR
Posted By dtmateojr
Replies: 312
Views: 18,388
It's an exaggeration lol! How many owners of high megapixel cameras print large? 4x6 does not count. 8x10 is small.

My K5 is only 16Mp, and I frequently crop it to 1x2 panorama which reduces it to 8Mp. Even at that size I have 1m wide prints on our wall and I can tell you that you won't see noise and you could stick your nose on it and you won't notice pixelation.

36Mp is a huge waste if you don't print.
Forum: Pentax Full Frame 03-19-2016, 04:13 AM  
K-1 So What Is Full Frame Going To Provide Over A Crop Frame DSLR
Posted By dtmateojr
Replies: 312
Views: 18,388
True. I think we are at a stage where the only factor affecting SNR is sensel pitch. You can't have good high ISO performance beyond a certain density. I just don't understand why manufacturers keep pushing for more megapixels when nobody even prints their photos anymore.
Forum: Pentax Full Frame 03-19-2016, 02:04 AM  
K-1 So What Is Full Frame Going To Provide Over A Crop Frame DSLR
Posted By dtmateojr
Replies: 312
Views: 18,388
We could have ended here. Let me repeat what you just said: DOES NOT TAKE INTO ACCOUNT SENSOR SIZE. You are correct. Print SNR has got nothing to do with sensor size or for that matter TOTAL LIGHT.

But let's continue...



Correct. The larger pixel results in better SNR. So obviously you are now comparing different sensors, yeah? Again you could have ended your argument here.



Of course because if you read my previous post, print SNR is affected by SCREEN snr.



So obviously, PRINT snr is not a measure of sensor size performance, right? Or light gathering. Otherwise there's no way a APS-C could match FF.



You just repeated what I said. PRINT snr has got nothing to do with sensor size. It's all about image size. If the APS-C was 36Mp it will match the FF in print snr.



Correct but not because it is able to gather more light but simply because it gives a larger image in terms of megapixels.




A very long winded response that repeats my last post:

PRINT SNR is affected by
1) SCREEN SNR
2) image size

Sensor size is nowhere in the equation.

If a smaller sensor is more efficient than the larger sensor then the higher SCREEN snr may result in a better print snr. If the smaller sensor has the same SCREEN snr as the larger sensor but has more megapixels it will also result in a higher print snr.

It just so happened that current sensor technology does not allow this anymore because FF sensors are really just enlarged APS-C as in the K5 and the D800.

Back when digital imaging was new and APS-C was only 4Mp I bet that the E-M5 will run circles around them for the fact that the latter has 4x the megapixels and the SCREEN snr will probably be the same. Even if the APS-C is slightly better in SNR, the sheer size of the m43 image will kill it.

So bottomline, sensor size has got nothing to do with print snr.

---------- Post added 03-19-16 at 19:08 ----------




Are you insulting me? Which is heavier a kilo of nails or a kilo of cotton?
Forum: Pentax Full Frame 03-18-2016, 06:31 PM  
K-1 So What Is Full Frame Going To Provide Over A Crop Frame DSLR
Posted By dtmateojr
Replies: 312
Views: 18,388
If you compare the dxomark snr measurements to film then we have:

SCREEN SNR = film grain (dependent on rated ISO)
PRINT SNR = film enlargement (interpolated from SCREEN snr)
NATIVE ISO = film speed as indicated in the canister
ISO = how much you push in the lab

So obviously in the case of K5 vs D800 and E-M5 vs 5DS the SCREEN snr is telling us that these sensors are essentially the same film emulsion. Meaning, they have exactly the same performance if exposed in the same way; same shutter speed, same f-stop. Size does not matter. A 135 film has exactly the same grain (noise) as the largest format of the same emulsion.

When you enlarge a film during printing the results will vary depending on enlargement size. An 8x10 sheet printed at 8x10 will obviously look better than an enlarged 135 film. Does this indicate film performance? It doesnt! You can enlarge 135 film to billboard size and you will never notice any quality degradation when you view it from 100 meters away. PRINT snr is relative to print size AND viewing distance and is NEVER an indication of sensor performance. FACT. MATH. SCIENCE.

Further to that, PRINT snr has NO, ZERO, NADA, ZILCH, NAUGHT, relationship to sensor size. PRINT snr is only dependent on
1) SCREEN snr
2) number of megapixels

An 50Mp E-M5, if such a beast exists, will match the performance of a full frame 5DS at any print size. Sensor size does not matter.

Therefore, equivalence is wrong.
Forum: General Photography 03-18-2016, 01:50 AM  
What do you think will happen to APS-C over the next 10 years?
Posted By dtmateojr
Replies: 111
Views: 4,492
Thank you. Please ignore me forever. You will never understand what SNR or resampling means and how they are related and unrelated to each other.
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