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Old Apr 15, 2005, 2:13 AM   #1
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Just wondering, it seems that a lot of camera's that have high MP's (8 )have only 4 or so X Optical Zoom. And most of the camera's with really high optical zoom 10X or 12X have lower (4 or 5) MP's. Any opinions on which is better and why?
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Old Apr 15, 2005, 5:17 AM   #2
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I guess the reason is price. Some cameras do have both like the Nikon 8800, Canon Pro1, Minolta A2

Large zooms and large Mp sensors cost money for the same price you can have one or the other.

As for which is best probably depends on how you plan to use the pictures you take.

A 1Mp camera is fine if you only want to view pictures on a monitor. If you go to a 4/5 Mp camera you'll get decent 10x8 prints. At 8Mp you're 10x8s may be a bit better and you have the ability to crop and retain a healthy number of pixels.

The other factor is what range does the zoom cover. A 10 zoom is no use if you want wide angle shots and it doesn't cover that. Likewise a wide angle zoom doesn't help if you want telephoto shots of wildlife.

I don't think there is an answer to the question what is best.

My view is set your budget. Think about how you want to use the pictures so that you can determine how many Mp you need then get the biggest optical zoom you can get from a quality manufacturer, making sure that the zoom range actually covers the range you're interested in.
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Old Apr 15, 2005, 7:08 AM   #3
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Nagasaki makes some great points. The only other thing I will add is - be realistic about how many 8x10 prints you are going to actually print or how much heavy cropping you'll be doing. If 90% of the time you are print 4x6 with an occasional 8x10 with minor cropping you are not going to get any benefit from an 8mp camera. You're really not. a 4x6 shot from a 4mp camera and one from an 8mp camera will be identical (assuming quality of both cameras is equal - big assumption). So, don't get hung up on megapixels too much unless you print large or do heavy cropping.
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Old Apr 15, 2005, 7:33 AM   #4
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brendak2000 wrote:
Just wondering, it seems that a lot of camera's that have high MP's (8 )have only 4 or so X Optical Zoom. And most of the camera's with really high optical zoom 10X or 12X have lower (4 or 5) MP's. Any opinions on which is better and why?

I would only look at the megapixels part if you need larger prints. IMO, 3 or 4 Megapixels is plenty for print sizes up to 8x10" (if you're not cropping) for acceptable quality.

It sounds like you're comparing some of the "Ultra Zoom" type cameras (Panasonic DMC-FZ20, etc.) with the 8MP Prosumer Models (Sony DSC-F828, Konica-Minolta DiMAGE A2, etc.).

As far as whichtype is better... that depends on how you're using a camera.

The main problem with producing a higher megapixel model with a long zoom lens is keeping the size/weight down to an acceptable level (if you want a reasonably bright lens).

The sensors used in the 4 and 5 Megapixel Ultra Zoom models are physically smaller than the sensors used in the 8MP Prosumer Models. So, the actual focal lengths of the lenses can also be smaller for any given 35mm equivalent focal length.

If you wanted to maintain the same lens brightness found in the Ultra Zoom Models while using an 8MP CCD (the Sony 2/3" type used in the 8MP Prosumer Models), the lenses would need to be larger and heavier for the same focal range.

The smaller 1/2.5" Sensors found in Ultra Zoom Models are not known for low noise at higher ISO speeds (because you're trying to pack 4-5 Megapixels into a tiny sensor). To try and pack even moreinto them would reduce the size of the photosites even more (making it harder to control noise levels). This is because you need smaller photosites for each pixel if you have more of them in the same size sensor (and smaller photosites require more light/ampflication of their signal for equivalent ISO sensitivity).

Of course, the 8MP 2/3" CCD is not exactly a "low noise champ" either. Even though this CCD is physically larger than the 4 and 5MP 1/2.5" CCDs, because you've got more pixels, the photosites are relatively small and prone to higher noise levels as ISO speeds are increased.

Now, we are seeing some longer zoom models with the 8MP CCD. For example, the Nikon Coolpix 8800. But, in order to keep the size and weight down, it's lens is nowhere near as bright as the lenses found in most of the smaller sensored ultra zoom models.

For example, the lens on the Panasonic DMC-FZ20 maintains it's f/2.8 brightness throughout it's focal range. But, the lens on the Nikon Coolpix 8800 does not. It stops down to f/5.2 at it's full zoom (equivalent to 350mm on a 35mm camera).

So, the lens on this Panasonic model is more than 3 times as bright as the lens on this Nikon model at longer focal lengths. This means that you could use shutter speeds several times as fast with the Panasonic compared to the Nikon for the same lighting conditions and ISO speed at longer focal lengths. This could be the difference between motion blur and no motion blur in less than optimum lighting conditions (or between usable pics and totally unusable pics).

If Nikon would have tried to make a model with a lens as bright as the Panasonic's at longer focal lengths using the Sony 8MP 2/3" CCD, it would have been a much larger and heavier camera (since the larger sensor requires longer actual focal lengths for any given 35mm equivalent focal length).

Of course, both of these sensor types are very small compared the sensors used in DSLR models. That's why a fast (bright) lens for a DSLR model is much larger and heavier (and you can't find a lens with the kind of focal range and lens brightness you have with the Ultra Zoom models for a DSLR camera in a single lens).

Take a look at the size/weight of some of the bright (i.e., f/2.8 throughout their focal range), long zoom lenses for DSLR models and you'll see what I mean. They are large, heavy, and expensive. But, if you need the lower noise of a DSLR model (since these can shoot at much higher ISO speeds with lower noise compared to the non-DSLR models), then you may not be able to find a smaller camera that meets your needs (for example, indoor sports, night sports, etc., where faster shutter speeds are needed) --- depending on how you want to use the pics (viewing sizes, etc.).

A DSLR with a bright lens is the obvious choice there (even though they will be much larger and heavier for the same focal lengths and lens brightness).

Basically, any camera you look at is a compromise (size, weight, cost, focal range, lens brightness, resolution, features, etc.).

You'll need to decide what conditions you'll be using a camera in more often (and how you'll be using the images) to help narrow down your choices.

BTW, if you really need the optical zoom (because you're taking photos of wildlife, etc., and you need the ability to bring your subject in closer), then you can't really easily make up for it with megapixels.

Because resolution, like area, is computed by multiplying height x width, it takes 4 times the resolution if you want to crop an image to make it like you used twice as much optical zoom (and still maintain the same amount of subject detail in pixels per inch).

So, even a 2 Megapixel Model like the Panasonic DMC-FZ1 can capture just as much (or actually more) detail at full zoom (equivalent to over 400mm with this model), compared to cropping an image from an 8 Megapixel Model like the DiMAGE A2 atit's full zoom setting (which is equivalent to 200mm in a 35mm camera). The Nikon Coolpix 8800goes longer (equivalent to 350mm in a 35mm camera), but then you can run into a problem with lens brightness at longer focal lengths if you are not in optimum lighting conditions.

Here is a table of popular long zoom models that shows how they compare at their full zoom lens settings. It's based on a formula known as Telephoto Figure of Merit:


Of course, you may not need to take a lot of photos at maximum zoom (I personally take most of my photos at the wide angle end of a lens), so take this into consideration when camera shopping.

Likewise, you may not need the ability to getfaster shutters speeds at longer focal lengths, and may value the higher resolution capability more.

Or, you may even decide that a DSLR isbetter (despite the size, weight and cost), if you have a need to take photos in lighting conditions where much faster ISO speeds are needed, or if you have a need for other benefits a DSLR may offer (like the ability to more easily control Depth of Field with aperture, autofocus speeds, shot to shot speed, etc.).

No one camera/sensor/lens combinationis going to be perfect for all users in all conditions. You'll need to decide what is more important in a camera and make tradeoffs to tryand find one that fits you better.

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Old Apr 15, 2005, 8:05 AM   #5
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I would not be surprised to see some ultra zoom type cameras come out using the new 7MP Sony 1/1.8" CCD at some point. Even though this sensor is larger than the Panasonic 4 and 5MP 1/2.5" sensors, it's smaller than the Sony 2/3" sensors.

So, it may be a good compromise for those needing longer zoom models with higher resolution in a relatively small package (although not as small as existing ultra zoom models for the same lens brightness)..

Of course, this is pure speculation on my part. We'll just have to wait and see.

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