Digital Camera and Webcam 101

[DCIScouts]

Digital Camera and Webcams 101

Table of Contents
1. Megapixel (MP)
2. Different Types of Zoom
3. Optional/Manual Settings
4. Lenses
5. Shopping FAQ


1. Megapixel (MP)
There is a lot of misconceptions surrounding the MP on a digital camera. Most people still try to apply the "more is better" idea to them because that's the most logical thing to do. However, for most people anything over 4MP is overkill unless you demand high quality prints or sizes such as a photographer or graphic designer. Here's a basic breakdown on MP and there comparitive picture sizes when printed out:

3MP: 8"x10" prints
3.2MP: 11"x14" prints
4MP: 20"x30" prints
6MP: 30"x40" prints

Higher MP = Bigger picture. If there is a picture that is taken at 3MP, this means that the picture will have 3 million pixels and so on.. the more pixels, the bigger the picture is, the better quality it is at bigger sizes because there are more pixels to accumulate one space.

These are the approximate sizes for picture print-outs (at home or at a store) at these MP qualities. The only thing that will affect these conversions is if you use digital zoom with the picture, this degrades the quality exceedingly fast. Cropping is also a concern, but with a 4MP you can crop over 50% of the picture and have an 8"x10" that would look the same if you had not cropped it at all.

2. Different Types of Zoom
Optical zoom: This is the physical zoom that is produced by the lens of the camera. The higher it is, the better your images will come out without losing quality because optical zoom maintains the resolution of the pictures taken without sacrificing anything to produce a closer view. It does so by physically moving the lense within the camera. What it does during this process is adjust the focal point so that it appears as if the object or landscape is closer to you.

Digital Zoom: This is created by the computer chip inside the camera that blows up the image internally so it looks as if the picture is getting zoomed in on. Unlike optical zoom which keeps the resolution of a picture and maintain the quality, digital zoom doesn't. All it does is removes all the pixels on the outside of the picture; then it takes the pixels that are left and fits it back into the same space and thus, makes it looks like it is closer or zoomed in on.

Extended Zoom: This isn't really a special feature; all it means is that the camera offers 8x optical zoom or greater. Most camera's offer 3x-6x optical zoom and any that has more, that's where the term get's used.

Example:

One way to think of it is to When considering image quality optical zoom causes no negative effects, and digital zoom will enlarge the pixels of the photo. Always look and compare optical zoom vs optical zoom when choosing a camera, not optical zoom vs. digital zoom. Additionally, do not confuse yourself where manufacturers combine their Optical Zoom and Digital Zoom together and state something such as "12x total zoom" where there is only 4x Optical Zoom and 8x Digital Zoom. The digital zoom will not help you very much. Read between the prints and look for it's optical zoom.

3. Optional/Manual Settings
The MP rating, picture resolution, shutter speed and various other settings can be adjusted by an on-screen menu of the camera. This is granted that the digital camera has an LCD screen. If it doesn't and everything is done manually, most of the controls will be on the camera itself (dial), and certain ones can be viewed through the view finder. One thing to consider when setting the MP rating on the camera is the size of the file. With a higher setting, you get a better picture but lose two other things. .

One, it causes the camera to act a little slower when storing the larger file size (affects response time, and the time it takes for the camera to be ready to take another picture).

Two, fewer pictures can be put on a removable storage media such as Secured Digital (SD) and Compact Flash (CF) cards.

Now, if you are using a digital camera that has the option for manual settings, you might see a dial at the top with just letters or little picture abreviations. Most manufactures will include documentation and explanations for all but here is a breakdown of some of the most common ones.

Snapshot mode: Auto mode; used for taking pictures
Program mode: Here, the camera judges the shutter speed and aperture for the shot that is going to be taken; can be used for average photography skills.
Aperture mode: Manual settings for manual adjusting of the aperture; you choose aperture, camera picks appropriate shutter speed. This varies from camera to camera. An example is F3.3 - F7.4.
Shutter mode: Manual settings for manual adjusting of the shutter speed; you choose the shutter speed, the camera chooses the aperture. Shutter speed range from camera to camera so this is something you will need to find out if you plan on using this feature. An example is 60 - 1/2000 sec.
Manual mode: You choose both the shutter speed and the aperture so you are in full control.

4. Lenses
Certain companies like Panasonic, Kodak, Canon and other camera manufacturers have been producing cameras for a long time and have higher lens quality as a result. Furthermore, some lens companies like Schneider-Kruesnach (Info) and Carl Zeiss (Info are featured on certain camera models. With a higher quality lens, images will be clearer and there will be less "ghosting" (vague, blurry lights, or objects in the image) on images .

Overall, if this if your first digital camera, and are used to disposables, then a cheap, no optical zoom camera may be a good option. Otherwise, I recommend a minimum of 3MP and 3x optical zoom to start, and then find the best camera for your needs.

5. Shopping FAQ
Frequently Asked Questions:

A. So guys, I have XXX amount of dollars and I want buy a digital camera, which one should I get?
Well, everyone's opinion on the best camera for XXX amount of dollars is going to be different. There are so many different brands and manufacturer's out there trying to pick the best one out of it is not possible. This is something that you have to ask yourself; What will I be using it for? How much MegaPixels do I need? Do I want battery life? Space? Manual or Automatic cameras? etc.

B. So ok, I found this camera (insert camera here) that fits my XXX budget, is it good?
Once you find it, it may and may not be the one.
First thing you should do is look up the manufacturer. Look up their history and see if they can be a dependable and reliable manufacturer you think you can trust. Do they make Digital Cameras, Film Cameras, SLR Cameras, etc.. Have they had any past issues with their cameras, etc.

Secondly, look up the camera; read over reviews from many different sites, not just one site because different people have different opinions. Read through several and see what they say, gather all the data and conclude if all reviews has been good or bad.

C. Ok, I did all that and everything about the camera and manufacturer is positive. However, I went searching for the cheapest price and see that it fluctuates from 50-200 dollars from site to site.
Remember the saying, "If it is too good to be true, it probably is"? Well, look around and try to find the average price the camera is going for and the MSRP. The average price is usually always lower than the MSRP if the camera is not brand spanking new. That will be the price most sites will be selling them for, but if one particular site is selling it 100 dollars cheaper than everyone else, don't automatically assume that's the best bargain.

What you want to do is look up the site at Reseller Ratings and see if they are a legitimate site. These are all user reviews and very helpful. "If it is too good to be true, it probably is."

D. Well, I don't care about the site review, it's the cheapest and I want it no matter what because that could just be that one case where it went bad.
Really? Let's say the digital camera you want is averaging around 350 dollars everywhere you go; but the site you are buying it from is selling it for 199.99. Everything goes through, shipping was just 15 dollars, you got it for 214.99. Here's what happens next:

• The site/place you bought it from will call you and act very nice to you. They will start selling you things you don't need like accessories, warranties, lenses, batteries, etc.
• Next, if you refuse.. they will try to add on to your total by saying things like, "oh, our package doesn't come with batteries," "there also isn't any software or manuals included."
• If you say that it's ok and you dont need them.. they will think of something uncanny and make you believe that the camera isn't sold in the U.S. and you will not be able to order any parts...

So what now? What now!? Well.. at this point, if you are still trying to get the camera for 214.99, they will say that their camera is out of stock and it will take another 2-3 weeks. If you refuse to buy it now, they will hang up on you and avoid you as much as possible. Then, you need to go through the process of getting your money back with your Credit Card company.

NOTE: something funny to think of.. most of these sites that sell digital cameras are from New York and if you see a couple of them, chances are that they are the same company just under different site names.

 

[Praetor]

Addendum

Megapixels
While there are valid points brought up about not giving too much weight to the number of megapixels a camera might feature it's important to consider three very important factors.

1. The camera. Not every camera is created equal -- a ten megapixel shot from my Casio EXLIM 1080 and a ten megapixel shot from my Canon Rebel XTi yield two totally different results (even ignoring crop). Why? Because the physical sensor on the RebelXTi is significantly bigger than the one on the Casio -- a bigger sensor results in cleaner prints (i.e. less noise). Even the ten megapixel shot from the Nikon D80 will be a bit different (as it has a larger sensor than the Rebel XTi)
2. The application. Sure a 3MP camera might be ok for 8x10s (I would disagree though) -- if you're shooting pictures for your 30" LCD -- which is 4.1MP, that won't cut it. While most of us dont have 30" LCDs, if you're main focus doesnt span the entire image (which, in the case of non-landscape photography, it usually is), the important parts of a the image wont be big enough to be displayed on 22" or 24" LCDs (which are much more prevalent)
3. Value. At the end of the day it comes down to value -- $200 five years ago might have netted you a 3MP camera -- now it net's you a 10MP one -- with more features. Realistically, the consumer market starts at 6MP

SLR-Specific
With a SLR camera, the emphasis is not on the camera body itself so much as the lens, the lighting and the expertise of the photographer. Many times, people transitioning from computer-tinkering to camera-tinkering get too caught up in the "gear" rather than the "art".

Lenses
Get the best lens that you can afford for the task at hand! A better lens will make the different between a blurry/dark shot and a crisp clear one. Some points to consider:

• SPEED. Generally, the faster the lens - the better. Lens "speed" is measured using a weird notation "f/#" where # is a number like 2.8, 4.6, 7.2 etc/ The lower the #, the faster the lens -- think of it as latency. Some lenses have two numbers (i.e. f4-f5.6) while others have just one (i.e. f/2.8). Lenses with just one number are described as being "prime" -- it has that speed regardless of whatever other settings the camera has been set to (generally, if you zoom in, your "#" will go up -- meaning, if you zoom in, your lens is going to be a bit slower). This may or may not affect you depending on what type of stuff you are shooting. An extension on that -- you may not even need a fast lens at all: most of the nighttime photography i do is done at f/22 anyways!
• Stabilization. Some lenses have a built in mechanism for compensating for our subtle gyration/motion as we take a picture. Different companies call it different things (Canon: IS, Nikon: VR, Tamron: VC etc). They all do the same thing really. Image stabilization is really neat if you're trying to take pictures and dont have a tripod handy -- but it may not be for you depending on what you're taking pictures of: if you're taking pictures of outdoor weddings or picnics or activities in bright sunny environments, usually you're shooting so fast it wont matter. if you have a tripod that really reduces the need for a stabilized lens. Another factor to consider is if the camera body itself has a built in stabilizer. The very popular Sony Alpha A100 has inbody stabilizer so any lens can be popped in and the results will all be stabilized!
• Focusing mechanism. I think it was originally pioneered by Canon, a focusing mechanism called USM (ultrasonic motor) but nowadays the technology is present on other brands too (i.e., Nikon's SWM, silent wavemoyot). Essentially a lens with USM 'technology' will autofocus faster and quieter than one without. Whether or not you need this is up to your specific needs -- personally I know a few shots of mine would not have happened without it (granted they were taken at 130km/hr of stationary targets)
• Type of lens. This important! You need to assess what type of photography you want to do -- wide landscapes, portraits, macro, zooms and buy the appropriate lens. For most people a 17-85 should sufficient to handle what they might need as a beginner.

Filters
While fanatics and pros will argue about UV filters affecting image quality -- if you're reading this, odds are you're gonna want to have a UV filter on your lens. While it helps to cut out haze from your image, it's major function is to protect the lens -- if you scratch it, you only have to replace a $50 peice of hardware rather than, say a $2000 lens.

There are other filters out there, one of the more popular ones is a polarizer. It's same idea as polarized sunglasses -- and its this filter that makes clouds and sky have some serious contrast and "punch".

There are zillions of filters out there and whether or not they are for you will depend on what you need to do. ND Grad filters (neutral density gradient) essentially reduce the amount of light entering the sensor which can be useful depending on what you want.



Other notes and suggestions

• ISO. No matter what, the lower the ISO number, the "cleaner" the picture. You'll want to shoot in as low an ISO mode as possible -- sometimes you cant (i.e. if you want to take pictures of fish at an aquarium -- which are usually very dim). Picking a lower ISO number means you'll need to either have a lower F/# and/or a slower shutter speed -- which isnt possible: the lens limits how low of a f/# you can go and the scene limits how slow you can shoot (ever try shooting tropical fish? the buggers dont sit still)
• Aperture This is the f/# thing. If you want the full version, have a read at this it's very well written. If you want the simple version, the lower the #, the 'faster' the lens (see above about faster lenses). A faster lens lets you shoot with less light and/or faster objects.
• Shutter speed This is litterally the amount of time the sensor is exposed to light. The total amount of light to touch the sensor is determined by the aperture (how big the hole is) and the shutter speed (how long light has to go through that hole). In a brighter environment, you'll want to increase the shutter speed. In darker scenes you'll need lower (aka "slower") shutter speeds which may mean u need a tripod. You can artificially add more light to the scene -- that's what flash is
• Metering mode This one is a bit complicated to simplify: it's the way that the sensor measures how bright a room is. Evaluative takes the scene as a whole and judges the whole scene for light intensity -- it's an average of the entire scene where ever spot is valued equally. Centre weighted does the same, but values the center area more. Spot metering measures the intensity just for a spot.