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Old Mar 12, 2010, 11:47 AM   #11
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I don't want to be a spoiler and I am an unrepentant cheerleader for Pentax (I think the Kx is the best DSLR on the market for the price point and beats far more expensive cameras on many levels. It is an underrated gem). I wonder, however, what this amount of megapixels can possibly provide, given that the eye simply cannot tell the difference even at larger print sizes? See this link http://pogue.blogs.nytimes.com/2006/...ogues-posts-2/. I have poster size prints hanging in my house from 4 megapixels to 12 megapixels and no one can tell the difference.
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Old Mar 12, 2010, 12:12 PM   #12
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To some degree I absolutely agree - megapixels and their benefit are way overstated for most use. But the point is - there IS a size that you can tell the difference at. Take your 4mp camera and generate a photo and a 40mp camera and create a billboard out of the two images. There will be the difference. What the article points out is the theshold isn't as low as people think.

16x24 is a lot smaller than billboard.

And, of course, if an image is cropped you lose pixels.

So, if you don't believe me - take photos with 4mp camera and 12mp where there is a good amount of fine detail and crop out 40% from each. Now have 16x24 color print done of each. view that print from 4 feet away and you'll see the difference.

So yes the average photographer places way too much emphasis on megapixels. But for professional use, more resolution is not a gimmick. But there is still the legitimate question of how much does a person need for what they intend on doing. For the hobbyist who isn't making such large prints, the biggest benefit is the dynamic range benefit over full frame.
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Old Mar 12, 2010, 12:30 PM   #13
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I agree with John and also think many may forget the size of the sensor and it's impact on the final product.
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Old Mar 12, 2010, 12:43 PM   #14
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i think its a good move for Pentax.

It allows them to get into a segment of the professional market that is not represented right now.

They avoid direct competition from Canon and Nikon and Sony by staying out of the FF market.

Yet they are priced many times less than the competition in the medium format realm. I think there will be a demand for this medium format camera in a reasonable price bracket.

that combined with their history in medium format. kudos to Pentax for doing something a little different and giving pros another choice if it fits their needs.
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Old Mar 12, 2010, 1:13 PM   #15
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I agree with Dustin on this. Very good move for Pentax. Forget trying to compete with Sony, Nikon and Canon. They can make themselves the 'affordable' medium format provider. Instead of trying to compete in a tough market, create their own market. Competing full frame is difficult - sony, canon, nikon have a distinct advantage in that they already have a number of professional grade, modern full frame lenses.

Now they're in their own market. While personally I don't have a use for medium format, I think it's a better decision than full frame assuming they have the right people in the division that understand the current market of medium format users (whatever that is). So I think it's a great segment, now it's a matter of being in tune with what is driving that market segment.
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Old Mar 12, 2010, 1:27 PM   #16
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Quote:
Originally Posted by pboerger View Post
From that article:

"One print had 13-megapixel resolution; one had 8; the third had 5. Same exact photo, down-rezzed twice"

That's not the same thing as capturing a photo using 13MP, 8MP and 5MP sensors.

I've seen that before (higher resolution photo retaining more detail after downsizing, when compared to a photo shot with a lower resolution sensor to begin with), depending on the camera and downsizing algorithm being used. That's probably because of the way a bayer pattern sensor works, where each pixel is only sensitive to one color (red, green or blue), and the demosaic algorithms have to combine values from adjacent pixels during processing from raw to give you a final image with red, green and blue represented at each pixel using sophisticated interpolation techniques. So, you can downsize it a lot using good algorithms and have far more detail than you'd have shooting with a lower resolution sensor to begin with. ;-)

IOW, the article's test methodology is flawed if you want to interpret it as trying to prove that a lower resolution sensor can perform as well as a higher resolution sensor (as that's not what they did, instead they used images from the same higher resolution sensor for all three prints).

Also keeping in mind that most professional printers are going to rez up the images to the same pixels per inch when printing them, making it much harder to tell the difference.
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Old Mar 12, 2010, 2:21 PM   #17
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IOW, a Bayer pattern sensor is not capturing as much resolution as you think (particularly with a color image), because of the interpolation algorithms involved in the demosaic process. That's why a newer 4.7 Megapixel Foveon type sensor can produce roughly the same resolution (looking at detail captured) compared to a 10MP or greater Bayer Pattern sensor, especially if looking at color resolution charts.

So, by downsizing a higher resolution color image from a Bayer pattern sensor (which is what they apparently did in that article's test), you're retaining far more detail than you would by shooting with a lower resolution Bayer pattern sensor to begin with, given similar sensor technology, lens, and image processing algorithms.

IOW, that's an *extremely* flawed article if it's suggesting that you can't tell the difference between a photo shot with a 5MP sensor as compared to one shot with a 13MP Sensor at a print size as large as they used; since they used the same higher resolution sensor for all three prints.

Perhaps their tech writer just doesn't understand how Bayer pattern sensors and demosaic algorithms work. I'll let you decide the what the article was trying to accomplish. But, I would certainly not reference it as how to compare images shot with cameras that have different resolution sensors, since that's not what they did with that comparison.
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Old Mar 12, 2010, 3:14 PM   #18
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Quote:
Originally Posted by JohnG View Post
I agree with Dustin on this. Very good move for Pentax. Forget trying to compete with Sony, Nikon and Canon. They can make themselves the 'affordable' medium format provider. Instead of trying to compete in a tough market, create their own market. Competing full frame is difficult - sony, canon, nikon have a distinct advantage in that they already have a number of professional grade, modern full frame lenses.

Now they're in their own market. While personally I don't have a use for medium format, I think it's a better decision than full frame assuming they have the right people in the division that understand the current market of medium format users (whatever that is). So I think it's a great segment, now it's a matter of being in tune with what is driving that market segment.
Yes, that's true. I think Pentax has a long past (film) tradition of offering excellent cameras in the 35mm slr range that appeal to advanced amateurs and some pros (LX) but they haven't gone head to head with Nikon or Canon.

They are well known for their fine medium format (film) cameras the 645 and the 6 X 7...which many were used by pro's. Not in sport's shooting or photo journalism...more in studio portraiture work, landscape photography, etc.

I'm pleased to see Pentax continue in this vein...I think they have reflected on their history and focused on niche markets that have been successful for them in the past.

I think that two of the most significant cameras introduced in the last while, IMO, would be the Sony 850 and the Pentax 645D.

Significant because Sony has fired the first salvo in what may...just may...become a bit of a war between Sony, Canon and Nikon as to who will offer the lowest cost Full Frame camera in the market.

Now I must admit I'm not a Sony fan, although I've had a lot of their equipment in the past, TV's, Video Cameras, MP3's, etc.

But having said that if all my Pentax DSLR equipment were stolen or damaged (touch wood this doesn't happen) and required replacement...I would look at the Sony 850 long and hard...although in the end, I would probably get a Pentax K7.

I do think that the 850 will have an effect on the full frame market and attract ASP-C users to Sony.

In the end, we as consumers may benefit with offerings of FF cameras from all three manufacterers at much, more reasonable prices.

The Pentax 645D I think will have a similar effect on the medium format market. Currently other MF digital cameras are very high priced....only a very successful pro photographer would be able to afford this system.

The Pentax MF digital costs while still enough to make one gulp hard, are a lot more reasonable. I think the MF makers will have to respond with MF equipment priced competitively.

As an amateur MF (Mamiya film system) owner...MF has a lot of appeal for me...but the costs of digital MF...even the Pentax 645D are prohibitive to my budget.

But I applaud both Sony for their 850 and Pentax for their 645 D.

We live in interesting times.

Last edited by lesmore49; Mar 12, 2010 at 3:19 PM.
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Old Mar 12, 2010, 4:07 PM   #19
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Demosaic algorithms? Bayer pattern sensor? I'm in way over my head here and should shut up. I hope they sell a million of them. Let's see, that would be ....well, a lot. Go Pentax.
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Old Mar 12, 2010, 6:19 PM   #20
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Originally Posted by pboerger View Post
Demosaic algorithms? Bayer pattern sensor? I'm in way over my head here and should shut up. I hope they sell a million of them. Let's see, that would be ....well, a lot. Go Pentax.
Virtually all modern digital cameras (with the exception of the Sigma models using Foveon based sensors) use what's known as a Bayer Pattern Sensor. Read more about that here:

http://en.wikipedia.org/wiki/Bayer_filter

Basically, each pixel is only sensitive to one color (either Red, Green or Blue) thanks to a color filter array that only lets one color through to each pixel.

During the processing the camera performs (conversion from the raw sensor output), it needs to use information from multiple pixels in order to store Red, Green and Blue values at each pixel location in the final image. As a result, you have far less resolution (especially with color images) than you would if all three colors were actually captured at each pixel location (and they're not with most sensors).

So, if you downsize a color image that has already gone through this demosaic process, you're going to end up with a lot more detail than you'd have with an image that is being captured by a lower resolution sensor with no downsizing.

The first time I saw someone demonstrate that (downsized image from a higher resolution sensor containing more detail than an image taken with a lower resolution sensor at the same resolution you're downsizing to), I was quite surprised until I figured out why. But, bottom line, the article you referenced is quite flawed, since all three images were taken with the same higher resolution (approx. 13MP sensor from what the article stated), giving you more detail in the downsized (13MP to 5MP) image than you would get using a 5MP sensor to take that 5MP image.
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