Reader Question: Is A Larger RAW File Better?

I recently received the following reader question from Michael S.:

Does the size of the raw file make a difference as to the quality of the final image? Looking at nikon d90 with raw file size around 10mb, sony a550 about 14 and the canon t1i around 20. is larger better? I have googled this question for hours and cannot find an answer.

My answer is after the jump, but if any of my readers have additional information to share with Michael please do so by adding a comment to this post. Thanks!

Mike,

The reason you’re not finding the answer to your question is because the size of the RAW file is determined by the sensor resolution. The more data captured by the sensor the greater the size of the RAW file.  More resolution isn’t always better particularly in smaller sensor where pixels are smaller and packed closer together. This creates a greater amount of digital noise at higher ISO settings.
Note: Even with in the same camera different ISO settings can result in different amounts of data stored with in a RAW file impacting its overall size.

Clearly higher resolution sensors (those with more megapixel) are going to provide you more data to create larger prints. For prints under 8×12 most any 10+MP camera will suffice. If you’re looking to make really large prints then you may want to consider a higher resolution camera, but image enlargements can be made with lower resolution cameras with the proper software depending on the subject.  Images with less detail are more forgiving with enlargements while images with a great amount of detail are not.

As of late there has been debate as to the necessity of higher resolution sensors if digital noise is kept to a minimum in smaller resolution sensors. NIkon’s introduction of sensors capable of capturing nearly noise free images at 4000 ISO revived this debate. Ultimately there are multiple paths to the same destination of high quality prints. While evaluating sensor resolution and noise characteristics are key aspects to any camera purchase decision you should also factor in other features that each camera provides.

So the answer to the question, “Is larger better?”
RAW file size is determined by the size of your sensor and can vary depending on your photos ISO settings. As to what sensor size you opt for depends on what your goals are with your photography and how much noise you’re willing to endure. Most any dSLRs at this stage will result in great images for the web. Different dSLRs will result in differing degrees of print quality and size.

I hope my answer and those of my readers help you in your camera selection.