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Old Jul 27, 2007, 11:58 AM   #1
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Hello,
I'm in the market for a new camera but keep reading about increased megapixels vs sensor issues. I have an olympus 765c 10x optical 4 megapixel camera and I can get decent 11x17 prints but I keep reading in the forum that the newer super zooms can't get good print quality at the larger formats? I was under the impression that with more megapixels the quality would be better in enlargements. Can anyone help me out with this one, I'm waiting for the reviews to come out on the new pani and fugi 18x's vs. the oly 550 to make a choice but I don't want any of them if I can't print a good quality photo at 12 x 18 inches.
Thanks
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Old Jul 27, 2007, 1:23 PM   #2
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Hi,

First of all a 11x17 print on a 4 megapixel 4:3 camera would be a PPI of 135.82. You mention that this is acceptable to you.

If you were to get a 8 megapixel 4:3 camera (such as the new fuji 18x or canon SI5) then the PPI of a 12x18 print would be 181.39. So you may see some improvement

This calculator http://www.mattspinelli.com/mpcalc.html will help show the gain you may get from a higher MP camera (I used parameters 4, 1.3333, 8, 1.3333, and 135.82):

Approximate Image Size:
Camera #1 ~ 2309 x 1732 [4MP]
Camera #2 ~ 3265 x 2449 (2x the pixels of camera #1) [8MP]

Resolution Gain:
Camera #2 has 41.4% more overall resolution than camera #1

What does this mean?
At 135.82 PPI the two cameras would make the following 3:2 and 4:3 sizes:
Camera #2 would print at 16.03" x 24.04" whereas Camera #1 at 11.33" x 17"
Camera #2 would print at 18.03" x 24.04" whereas Camera #1 at 12.75" x 17"

Please note that this assumes that lens quality is high in both cameras, that noise levels are low, that ISO levels are low, the the cameras internal processing is the same and that any other aspect that affects image quality is the same. However this is rarely the case in real life because noise increases with pixel count on cameras that have the same sensor size and there is an other issue at hand.

The other problem is that these ultra zooms have tiny sensors (thus noise is more for the 8 MP as mentioned) but also that diffraction starts to come into play as well. My calculator does not take into account diffraction and it really should. Maybe I'll update that someday.

The bottom line is that I think you will see some improvement as long as you expose well and use the lowest ISO setting. But even then it is not likely 41.4% to be better due to issues mentioned above. 12x18 should be easily doable if 11x17 was acceptable to you with your 4MP camera.
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Old Jul 27, 2007, 2:42 PM   #3
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nelmr wrote:
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and that any other aspect that affects image quality is the same. However this is rarely the case in real life because noise increases with pixel count on cameras that have the same sensor size and there is an other issue at hand.

The other problem is that these ultra zooms have tiny sensors (thus noise is more for the 8 MP as mentioned) but also that diffraction starts to come into play as well. My calculator does not take into account diffraction and it really should. Maybe I'll update that someday.
Herein lies the key. If NOTHING ELSE IS CHANGED, the same size sensor with MORE mp will have more image problems than the sensor with fewer MP. Having those pixels closer together causes problems. So, when a manufacturer decides to cram more mp on a sensor they have to make additional changes just to keep the same quality level. The problem is: camera manufacturers are victims of their own marketing. Unfortunately, megapixel cout has become the benchmark that the uninformed public uses to judge digital cameras by. So, manufacturers are constantly striving to stuff more MP on their cameras because why would someone buy an 8mp camera when 12mp are available? But when they do this they often don't have the necessary technology improvements in place to maintain the same image quality. So very often the first generation of higher MP cameras will have worse quality than the lower mp cameras they replace. Bythe 2nd or 3rd generation the manufacturers typically find a way to iron out the bugs and can get image qaulity that meets or exceeds the quality of the lower mp camera. This is especially problematic in digicams where every 6-8 months a manufacturer must release new models. And always the pressure is on them to increase MP count because the buying public uses that figure more than any other to judge the quality of a camera by.
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Old Jul 27, 2007, 3:32 PM   #4
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Thanks to both of you for trying to clear that up for me. I'm guessing some of this can be adjusted in photoshop? It allows you to make many adjustments such as pixels, noise, etc, etc. But what you're basically saying is they're not increasing everything proportionately and the quality suffers. Short of buying a dslr I may have problems finding a larger optical zoom with more megapixels that will give me any better quality at larger print sizes than what I have.
Thanks again
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Old Jul 27, 2007, 3:34 PM   #5
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John,

I do think that just about any new ultra zoom that doesn't have major flaws today should be able to handle 12x18 if the the thread starter is comfortable with a 4MP image @136 PPI (11x17 print).

12x18 = 181 PPI on a 8MP camera. The true resolution gain from an 8MP new ultra zoom would have to be less than 6% for the 4MP camera to do a better job making larger sized prints. I mentioned that it likely is not 41% better, but I think at least 6% would be a safe assumption.

esharri,

You may want to consider Fuji's 6MP super zoom using the SCCD (model S6000 fd/S6500 fd) which has better noise and resolution than the typical Bayer sensors in all other ultra zooms. It's a 10.7x zoom (28-300mm). Not quit as big as 12 or 18x but it will give you better images and may even outresolve (or at least match) some of the higher pixel count cameras due to the sensor technolgoy.
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Old Jul 27, 2007, 4:48 PM   #6
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Thanks Nelmr,
Perhaps I wasn't clear enough on what I was looking for. It's not just print size, I wanted to purchase a much larger optical zoom if I could get the quality at tabloid sizes or more. I shoot a lot of wildlife and sometimes they are 150 yards away. My little 4meg 10x just doesn't have it at that distance. It takes great shots under 100 yards although at times I wish it had IS which it doesn't. A larger zoom would mean less cropping and resolution loss but that does me no good if I can't get the quality to go with the zoom.
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Old Jul 27, 2007, 4:54 PM   #7
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esharri wrote:
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Thanks Nelmr,
Perhaps I wasn't clear enough on what I was looking for. It's not just print size, I wanted to purchase a much larger optical zoom if I could get the quality at tabloid sizes or more. I shoot a lot of wildlife and sometimes they are 150 yards away.
I hate to burst a bubble, but more MP isn't going to get you great results at those distances. 150 yards you're talking about needing equivelent focal lengths of 800mm or more. You need to either get closer (and still get more zoom) or come up with $3000 or more to get some DSLR equipment if you want to shoot wildlife at those ranges. You can't crop your way to decent images - especially not for printing that large.
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Old Jul 27, 2007, 7:45 PM   #8
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I understand that but 18x is over 500mm equiv, quite an improvement over my 10x. I was originally thinking more megapixels, more optical, better thing. But as I read through the forums I'm reading not necessarilly so. Going back to my original question which you guys have answered, they haven't increased the sensor and jamming more into the camera creates noise and other issues. How much quality is lost using a 2x teleconverter, that may be another option.
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Old Jul 27, 2007, 10:53 PM   #9
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The Oly 550 hasn't tested out too well and is the only 18X I've seen reviews on. Panasonic and Fuji have announced 18X zoom cameras with optical stabilization. But before people can get their hands on them one has to guess there will be compromises. The stabilization on the Panasonic will probably be a little better than the 550 based on track record. Who knows with Fuji's first venture into stabilization how good it will be. Panasonic insists on using their own sensors and they are usually noisy. Fuji doesn't do that great going over 6Mp either. Leica will probably make a better lens for Panasonic.

IMO you would be better off waiting to see whether the new Fuji or Panasonic sort out than going with a converter. You will not be able to use a 2X converter at full zoom without a tripod. With no stabilization and the converter cutting the effective aperture you will be lucky to shoot something in bright daylight handheld. You would be better off with the 550UZ.

I think some of the numbers quoted in this thread leave something to be desired. Based on the ability of the lens to resolve detail the images have improved along with the Mp. This is the resolution chart for some 4Mp cameras with relatively large 1/1.8 sensors:



This is a resolution chart for some 7Mp superzooms with smaller sensors. The FZ30 is 8Mp with a small sensor:



Keep in mind that vertical and horizontal LPH is a linear measure of a two dimensional image. Actual resolution increases with the square of the linear increase. Resolution hasn't quite kept up with Mp but it is significant.

I saw a substantial improvement in large prints going from 4 & 5 Mp to 7 & 8. And I didn't see any particular increase in the work I had to do in Photoshop. But I'm pretty thorough in Photoshop with any large print. Going from 4 to 8 Mp you can make a print the same size with twice the pixel density or make a print of the same resolution with twice the area. In my experience that really shows.

One frustration to me is they don't let you turn the in-camera noise reduction completely off without using raw. Raw is an acceptable format for me with most Panasonic cameras because the cycle times are decent with the Venus engine. The 550UZ would be unusable to me in most situations. I had another camera with similar cycle times for raw and used it only for completely static situations although I really preferred raw.

I can do a much better job with the noise using a good Photoshop plug-in. I just apply what is needed to parts of the photo and eliminate the edges before applying any noise reduction. Prints can come out very nice from a moderately noisy image. But it is hard to do anything with overly aggressive in-camera noise reduction.




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Old Jul 27, 2007, 11:09 PM   #10
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A quick check of the specs shows your C-765 as having a 1/2.7" sensor. Most of the newer superzooms use a 1/1.8" size, which is a bit larger, so the increase in number of pixels is partly compensated by the larger size.

I tend to think of it as blowing up the image on the sensor. The image on smaller sensors has to be magnified more for the same print size, than a larger one. If the sensor height in mm is double, you can put twice as many pixels on it for the same pixel size and, other things being equal, the same quality.

I had a bit of a time trying to figure out why I got so much better resolution from my 6MP DSLR than from my 5MP fixed lens camera. (side by side, same equivalent focal length). The digicam has a 2/3" sensor and the DSLR is APS-C. Both have excellent lenses. My conclusion was that the image on the DSLR is approx 2-1/2 times the size of the digicam, so the digicam image has to be magnified 2-1/2 times more for the same size print, with resulting loss in quality.

Resizing and interpolation can help, but since they can be applied to both, the DSLR still has the advantage.

I know this doesn't answer your question specifically, but should help you decide.

For your situation, a quality teleconverter could be the answer. I have heard very good things about the Oly T-cons. The larger objective size gathers enough more light that you don't lose any shutter speed, and image quality is said to be excellent.



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