14 November 2011

Blasting the myths - Comparing cameras

This post is about comparing cameras and reading between the lines of any offer/marketing campaign. Manufacturers/retailers often take buyers for a ride by focusing on irrelevant aspects of the equipment. Come on! No manufacturer/retailer will tell you that lens a which seems to be similar to lens b is better than lens b and at the same time, is cheaper too! How then would you weigh the equipment and see if it suits your needs? Lemme suggest some facts to look out for.

The more the megapixels, the better is my camera!
WRONG!! 'Megapixels' is neither the muscle nor the brain of the camera. The heart and soul of the camera are its sensor and lens. But the manufacturers always market a camera on the basis of megapixels and the brand of the lens. Occasionally, some camera models are marketed on the basis of additional features like shooting modes (night mode, etc). Do you see posters claiming that this camera has a such-and-such sensor and a lens of this construction? No! The reason is simple - it would either confuse the casual buyer or it would make the moderately serious buyer wise and help him/her choose the best :) 

Here are some articles that explain this concept beautifully. The second article illustrates the entire concept of megapixels, dpi and print sizes with amazing simplicity and depth. I suggest that you read it patiently and completely. You will definitely have a bone to pick with every person who pushed you into the megapixels race :)

Besides the fact that each image resolution has a best maximum-print-size, "Pixel Pitch" is a concept that should convince you to step out of the megapixels race. Pixel Pitch refers to the size of the pixel on the sensor. Take a sensor of  2x2 inches (these are dimensions quoted for this example and do not refer to actual dimensions of any existing sensor to the best of my knowledge) and stuff 1 mega-pixels in it. Now compare this to another sensor of the same dimensions loaded with 10 mega-pixels. The latter will obviously have pixels which are 1/10th the size of those on the former. These pixels would absorb less photons and hence generate a weaker electrical signal which is sent to the processor for composition of the jpeg image. Since the signal is weak, it needs to be amplified. Artificial amplification of this nature, engineers would agree, introduces noise in the signal and hence, in the image that is saved. Hence, cutting the long explanation short, more mega-pixels on the same sensor size would lead to degraded performance. By now, if you are still reeking from the hangover of more mega-pixels, you have foresaken the right of blaming your wife for your depleting bank balance :)

To conclude, do not set mega-pixels as the main ground for comparison between two cameras.

This has a Carl-Zeiss Lens
Ok I don't really see how having a Carl-Zeis lens makes me cast all other options aside and run into your arms! I have not seen any Sony poster try anything besides this for the past few years. Look at Nikon - atleast they have Deepika rooting for them :p As for Canon, they countered Nikon's hottie with the Indian maestro of cricket - Sachin. Cmon Sony...catch up!

A camera lens is a sophisticated piece of engineering with multiple high-quality elements built into it. Determining the performance and grade of a lens is a complex process, best left to professionals. You should read up on reviews by camera magazines/websites to understand the performance of the lens in question. A very reliable and popular website for photography reviews/tutorials is Digital Photography Review. The lens elements and its architecture determine the performance of the lens, and not the brand name of the manufacturer. For example, though it may be a lens from a reputed manufacturer, it may not be a good performer at the telephoto-end or the wide-end or in the mid-zoom-ranges or it may not focus in low-light conditions.

Image Courtesy : artandstructure.com
Sensor Size
Camera sensors come in different sizes. The most basic differentiation is full-frame and cropped sensors. A full-frame sensor has almost the same size as that of a 35mm film frame. A cropped sensor is smaller in size. If you read up on Pixel Pitch, you would understand that sensor size greatly affects camera performance. In Nikon, the cropped camera bodies carry the prefix "DX" while full frame sensors are labelled as "FX". Canon uses the terms APS-C and APS-H respectively for the same.
I personally do not prefer pen-cell batteries. They wear out soon and it is difficult to find the right charger-battery combination when you need to. What I mean is, though I may buy a Eneloop battery and charger combination this time, on a trip I might buy another brand of batteries or may forget the Eneloop charger and end up buying a different brand of charger. Contrary to popular belief, for long life of your rechargeable batteries, use them with their brand of charger. Do not mix batteries of one brand with a charger of another brand. Also, choose NiMH batteries over the NiCd which are banned due to their toxic nature.
ISO Performance
Compare cameras on their ISO performance. Better cameras offer less noise at higher ISOs.

List of accessories that can be coupled with the equipment
Some of the accessories that you can couple with you camera are remote trigger, flash, filters, list of lenses, tripods, spirit gauges, camera bags, camera body protection covers, etc. For example, some cameras do not allow you to attach a flash light onto the camera. Look out for these details. Some cameras don't even come with a built-in flash.

Continuous click speed
If you are interested in click images in burst mode (in this mode, the camera keeps clicking images at a fast rate until you release the shutter button or until the continuous-click limit has reached), then you should look at this rate. The higher the rate, the more the shots that can be clicked in quick succession. This is useful for example, if someone is diving into a pool of water and you want to capture the transition from the diving board to submersion.

Dioptre Correction
This is useful for you if you wear specs. The dioptre can be calibrated by you so that you can look into the viewfinder without wearing your spectacles. This is very helpful during long durations of a photo shoot session.

Image Resolution
Look at the maximum image resolution that the camera can produce. Choose the one with the higher value.

Viewfinder/LCD Screen coverage
This is the amount of area that the screen/viewfinder lets you see. For example, if this value is 98% for your camera, it means that what the screen/viewfinder shows is 98% of what will be saved in the captured jpeg. Hence, this can interfere with your judgement what should go into the final jpeg. An occasional foot of a passerby or a blurred wagging tail of a mongrel would eventually irritate you enough to swear in the name of your innocent camera :)

Supported Memory Card
If you already have a set of extra SD memory cards, why chose the camera that supports only the other type of memory card over the camera that works with SD cards? There better be a good reason if you still choose to go for the other camera.
Video Capabilities
In case you want your digital camera to work part time as a video camera, then compare the video capabilities of the options before you. Look for video resolution, maximum video length, stereo sound support. These days, most cameras boast of HD video. Believe me, HD is awesome! Read up on HD here.

Live View Mode
Not all cameras support the live-view feature wherein you can see the image in the screen before you click the image. In most entry level DSLRs, you need to look through the viewfinder to see what the camera is seeing. The LCD screen in such cameras is used only to see the saved image and browse through settings.

Here is a comprehensive list of camera attributes that you can look at while comparing two cameras. You would seldom find these details at the retailer's outlet and would need to read up on the internet before heading out to the store. This is another brief article to help you understand that you should not go by the manufacturer's words.

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