SD850IS - F2.8 - F5.5Panny TZ3 - F3.3 - F4.9.

I've given up trying to Google it. Between those 2 lenses, who hasthe advantages and in what situation? Eg; is the Canon better allaround b/c it has a larger complete range? Which doesn't make senseto me b/c it's only 35-140mm compared to the TZ3 at 28-280mm. Doesone of the lenses above let in more light to make it better forindoor photography?.

The truth is that the differences are really small and don't matter at all. Not one bit..

(You know what the numbers refer to? It's the range of widest/brightest apertures. It has to be a range on a zoom lens because the figure changes depending on how far you zoom. The first number is at wide angle, the second at telephoto. It only refers to the BRIGHTEST apertures though, not the full range of possible apertures.).

You only need be interested in these figures if the second one is a very high number. So if it was F2.8 - F8.0 the camera would take rubbish pictures when you zoom all the way..

For these two cameras, the numbers are fine, unremarkable, of no consequence. If you're interested though, the Panasonic is perhaps more impressive because it is brighter at the long end of the zoom, even though the long end is longer than the Canon's. But actually it doesn't matter. Won't make any difference to the photos..

The big difference between these cameras, apart from physical size, is that the Panasonic has a massive zoom range that just blows the Canon away. This is what you should be thinking about..

Androohttp://Androo.smugmug.com..

The bigger the number, the smaller the hole. The smaller the hole, the bigger the depth of field, and the less light gets through. Easy peasy..

However, with a small sensor camera, DoF is almost always very deep anyway, so really all the small hole does is to restrict the light hitting the sensor, allowing you to shoot in very bright conditions or at very slow shutter speeds..

The reason there is a variable aperture number given is all down to the physics of light and lens design. I understand it, but can't explain it simply (maybe that means I don't really understand it...?). You CAN have a non-varying aperture in a zoom lens, but it adds a lot of size and a lot of expense..

But to address your questions individually....

Between those 2 lenses, who has the advantages and in what situation?.

At the wide angle end, the Canon is slightly faster. At the telephoto, the Panny wins (but neither of them by much)..

Eg; is the Canon better all around b/c it has a larger complete range?.

No. The Canon is better at wide angle, but loses when the lens is zoomed right in. Smaller number = more light, so therefore the Panny wins at the telephoto end..

Which doesn't make sense to me b/c it's only 35-140mm compared to the TZ3 >at 28-280mm..

It has nothng to do with the actual zoom range - it's all to do with how much money the manufacturer thinks you're willing to pay to have a fast lens, and then how they spec the camera. Most people in this market have no idea about how it all works, so the camera only has to be 'reasonable'. I have a 70-200mm zoom lens for my Nikon dSLR. It's a constant f2.8 (it doesn't change as I zoom in). But it costs about US$1600. Just like a car, speed costs money..

Does one of the lenses above let in more light to make it better for indoor photography?.

If you only ever shoot wide angle, then the Canon is marginally better. If you walk around with the lens at the maximum telephoto, then the Panny works better. Personally, I wouldn't worry too much about the aperture of the lenses on these type of cameras. Buy the one that suits you best from the standpoint of any other features it has, and you'll be happy. The difference between the aperture of the lenses is so small as to make no difference most of the time. If you want the big zoom, then get the TZ.



To steal a quote from someone here - Buy what makes you happy; anything less makes you less happy!.

Rob.

Everyone, everywhere, has to do everything for a first time. There is no failure in failure, only in failing to learn...

PanaNewbie wrote:.

Comparing these 2 cams:.

SD850IS - F2.8 - F5.5Panny TZ3 - F3.3 - F4.9.

Smaller numbers= better (for specs, not always for photos).

The two numbers aren't the ranges; they're the maximum aperture (max aperture= smallest F number available) at the short and long ends respectively..

So, the first camera has the advantage at the short end, while the second camera has the advantage at the long end..

Short end= zoomed out.

Long end= zoomed in...

Excellent, thanks for the info everyone, makes sense now!  .

Alienshards wrote:.

PanaNewbie wrote:.

Comparing these 2 cams:.

SD850IS - F2.8 - F5.5Panny TZ3 - F3.3 - F4.9.

Smaller numbers= better (for specs, not always for photos).

The two numbers aren't the ranges; they're the maximum aperture (maxaperture= smallest F number available) at the short and long endsrespectively..

So, the first camera has the advantage at the short end, while thesecond camera has the advantage at the long end..

Short end= zoomed out.

Long end= zoomed in...

Think of taking a picture being equivalent to filling a bucket with 1 gallon of water with a hose.

The width of the hose would be equivalent to the aperture. A bigger hose means a more water (light) can enter the bucket and fill it quicker.

The amount of time the hose is turned on is equivalent to the shutter speed. The longer the hose is open (shutter) the more water (light) enters the bucket.

The water pressure is equivalent to the ISO - The higher the pressure (ISO), the quicker the bucket is filler, but higher pressure (ISO) means a messier job..

So, to fill the bucket with one gallon of water you can adjust any or all of the variables.

(Width, time, pressure). There are many combinations that will fill exactly one gallon..

Let's say you have a favorite size hose. If it fills too quickly, you simply turn the water on for a shorter time. If it fills too slowly, you increase the amount of time the "shutter" is open. But, if it is open too long for your situation, you can merely increase the water pressure (ISO).

HTH,DOF..

First, the smaller the number the better. That number is related to the amount of light that is let into the lens. Never mind the precise relationship, but smaller is better. The number relates to the BEST aperture for that lens..

Secondly some zoom lenses usually have TWO aperture numbers, like F2.8-4.5 for example..

The first number refers to the short end of the zoom range, the second to the long end. So a lens might be describer as 28-300mm F2.4 - 4.6, which means the best aperture possible at 28mm is F2.4 and the best aperture possible at 300mm is F4.6..

Generally more light is preferred, but of course it's only useful if the camera has a sensor that is also efficient..

StephenG.

Fuji S9600Fuji S5200Fuji F30Fuji E900Canon A710ISPCLinuxOS..

SD850IS - F2.8 - F5.5Panny TZ3 - F3.3 - F4.9.

The amount of light is inversely proportional to the F-number squared; therefore,.

At the wide end, SD850/TZ3 3.3/2.8)^2 = 1.39At the long end SD850/TZ3 = (4.9/5.5)^2 =0 .79.

The canon lets in 39% MORE light at the wide end and 21% LESS light at the long end..

These are not inconsequential numbers in low light situations...

You tend to need more light as you zoom. At wider angles you can compensate with a lower shutter speed if you arent shooting motion. As you zoom you need more shutter speed and therefore more light. Stabilization helps, but both cameras have about the same stabilization effectiveness and the relationship is the same..

The aperture difference is small with the Canon at 140mm equivalent and the Panny at 280. But with the Panny at 140mm it probably has a significant advantage over the Canon at 140 as the change is usually pretty much linear. I would guess the TZ3 is somewhere around f4 at 140mm. There can be a pretty big difference in your success rate with a stabilized camera at 1/30 second at 140mm compared to 1/15...