Entertainment Mania: Digitial Camera- Tips before buying Digital camera

Megapixels

Remember it takes 4 times as many megapixels to make an 8x12 print as sharp as a 4x6 print.
You need 12.8 megapixels to get double the resolution of 3.2 megapixels.
You might not be able to see much difference in a print made from 3.2, 4, or 5 megapixels.
You can make a surprisingly large print from a 3.2 megapixel image.
Experiment for yourself by displaying part of a picture on your computer monitor and calculating how large a print it would make at that magnification.

Digital Sharpening

Most digital cameras will "digitally sharpen" pictures before saving them.
A little bit of sharpening is usually a good thing but it introduces visible artifacts so some cameras let you control how much or little sharpening is done.
You can always sharpen later with software on your computer--you can't as easily unsharpen to remove the artifacts.
There is considerable variation between cameras in the amount of sharpening done by default.

Battery usage

Digital cameras use A LOT of battery power (much more than film cameras)! This seems to be largely due to the amount of computation required to capture and save the image after you take a picture and to continually update the display before taking a picture.
Although they all use a lot, some models use much more than others. Be sure to check how long a charge (or set of batteries) will last.
Can you save power by turning off the display? If so, is the camera sill usable?

Will it still briefly display the picture after you take it?
Do all the shooting modes still work with the display off?
Does it slow down camera operation to have the display off?
Can you change camera settings with the display off?

Does the camera use standard AA batteries?

If so, can you use standard (cheap-to-replace) NiMH rechargeable batteries?
In a pinch, can you also use alkaline or single-use lithium batteries?
The fastest AA NiMH battery chargers take only 10-15 minutes and charging batteries outside the camera means you can still use it while charging if you have another set of batteries.
Does the camera correctly detect the kind of AA battery in use and adjust the low-voltage threshold accordingly? (For example, the Nikon 3100 has a low-voltage threshold set for single-use lithium batteries. If you use NiMH batteries, after just a few shots are taken, it says the batteries are low and soon after refuses to use them).

Viewfinder type, accuracy, usability.

How accurate is the viewfinder?
What information about camera settings is visible in the viewfinder (if any)?
If camera settings can only be seen/changed on the screen, consider how useful the viewfinder will be if you can't see the screen without your glasses or in bright sunlight.
Some viewfinders are optical (like on film point and shoot cameras) and some are miniature screens behind an eye-piece (like video cameras).
Optical is clearer but usually less accurate.
Video is typically low-resolution, slow to update but more likely to show camera settings and be usable in bright light.

Playback Magnification

After you've taken a picture, can you zoom in on the display enough to check if the focus is good or if there is purple fringing? (About 10x playback magnification is needed for that).
Assuming you can magnify 10x or more, is it reasonably fast to do so?

Some cameras let you zoom and crop a photo you've already taken into a new photo (in the camera). This may be useful if you're going to print directly from your memory card but it may be more useful as a way of gaining more playback magnification (if the camera doesn't have enough to tell if a picture is really in focus).

Which camera settings persist after you turn off the camera?

Are the choices sensible? (If you always want to take pictures at the highest quality, can you set that once or must you reset it each time you turn on the camera?)
Will the settings persist if you take the batteries out to charge them? If not all settings, at least the time and date?
Some cameras have a separate watch battery for keeping settings while the main batteries are out.

Is there a panorama mode?

This lets you take several pictures which overlap and later "stitch" them into one (more or less) seamless picture on your computer. (Seamlessness takes care and effort).
Does the panorama mode help you compose your panorama by showing you a piece of the previous picture on the screen so you can line-up the next component picture?
Does the camera come with "panorama stitching" software which will run on your computer?
Does the software refuse to stitch pictures not taken in panorama mode (such as in manual or some other scene mode)? Some Olympus software has this limitation.

Is there EXIF header display?

In playback mode, can the camera display all the modes and settings in effect when the picture was taken? Usually they're all recorded in the "EXIF" header in a JPEG file but not all cameras let you see the values on the screen.

Effective ISO

Many cameras can automatically increase the effective "film speed" when subject is slightly beyond the range of built-in flash.
Do you get any control over this for other situations?
How much ISO boost is available? (Canon A70 goes from ISO 50 to 400)
How much ISO boost can be used before noise becomes unacceptable?
Some cameras have much less noise than others at boosted ISO.

Is there a "best shot selector" mode?

Some Nikons have this and it is fantastic. It lets you press and hold the shutter release and take 10 pictures in rapid succession and the camera will automatically choose and keep only the sharpest. If you're not using a tripod or flash and you need to use a slow shutter speed, this is much faster than taking a picture, reviewing it, deleting it, trying again and again until you get lucky and one is sharp enough.

Some cameras let you attach voice memos to your pictures. This may be handy, though I haven't used it (because it is too awkward to do on my camera).

Can one set the camera to take a series of pictures as long as the shutter release is pressed? If so, how fast can it take them? (Usually depends on size and compression settings).

Can the camera take any pictures using just its built-in memory? Can the built-in memory be used to transfer pictures from one memory card to another?

What USB protocols does the camera support?

USB 2.0 allows much faster data transfer than USB 1.1 (but either will work).
"Picture Transfer Protocol" (PTP) is supported on Windows XP and Macintosh OSX but not so well on older OS versions or Linux/Unix.
With the right software, some cameras can be operated (remotely) from a computer using PTP.
"USB mass storage" (which makes the camera look like a disk drive) works for all computers with USB and is also what you get if you take the memory card out of the camera and put it in a card reader.
Using a card reader also means you won't need to run down your batteries while transferring pictures from (or to) your memory card.
(Card readers cost as little as $10.)

Video output

Some cameras have video output so you can view your pictures on a TV (at low resolution). If the camera has this feature, it may also have a "slide show" setting where it will automatically cycle through the pictures. (This can be nice at Grandma's house if she doesn't have a computer.)

Some digital still cameras can take short low-resolution video clips. If this is of interest...

Is there sound too?
Can you edit them in-camera?
What is the resolution, frame rate and maximum recording length?

Type, size and speed of memory card

Whatever format you use, it may be wise to get two half-sized cards rather than one giant card so you have a better chance of not losing all your pictures at once if your card gets damaged or corrupted.
Flash memories have a maximum read and write speed usually given as 4x or 12x. Faster is better until the camera (or card reader) becomes the limiting factor. (I think x=150kB/s like CD speeds).
Some people think the older/larger "compact flash" is more robust and less likely to get damaged than some of the smaller formats (especially "smart media").
Occasionally airport X-rays can corrupt data on your memory card. A card format which you can carry through the metal detector (avoiding the X-rays) may be worth some consideration.

Below are some models which you love to purchase-

Sony Cyber-Shot DSC-HX100V 16.2 MP Exmor R CMOS Digital Still Camera with Carl Zeiss Vario-Tessar 30x Optical Zoom Lens and Full