This Awesome Crop Sensor Calculator Cuts The Confusion


At the root of many forum debates comes the inevitable confusion and pointless bickering over what a certain sensor size means for your images and how they are “cropped.” Don't worry, we're not going there. Though crop factor is here to stay amongst digital cameras, so it's best we get to grips with it.

photo by sharegrid
Photo by ShareGrid

What Is A Crop Factor?

Now, I'd definitely recommend reading one of our articles on Crop Factor, like this one here:

From here you'll have a very good understanding about different sensor sizes in digital cameras and more importantly, what they mean. Anyway, amongst all the digital sensor noise from the crowds, there will inevitably come a point where you need to calculate the full-frame equivalent focal length and/or f-stop.

crop sensor calculator
mmCalc – The Crop Sensor Calculator

The Crop Sensor Calculator

Welcome to the mmCalc Crop Factor Calculator. A very handy online tool to quickly convert equivalent focal lengths and f-stops to their Full Frame counterpart (36 x 24mm – the largest sized sensor found in a DSLR).

You could be using an APS-C Crop Sensor camera (23.6 x 15.8mm Sensor) applying a crop factor of 1.5x to 1.7x (Nikon 1.5x and Canon 1.6x) or something smaller still like a Four Thirds camera (17.3 x 13mm Sensor), in which case you'll have a 2x Crop Factor to consider as the sensors are one-quarter the size of a full frame sensor.

How To Use mmCalc Tool

With that brief explanation out the way, you could find the tool really very handy indeed – this isn't to say it's something you'll be continually referring to, but the mmCalc tool a great easy-to-use calculator and contains a well-explained description of your calculation so you understand the information being presented to you.

At the end of the day, you're going to at the very least learn more about camera sensors, their sizes and why these conversions even take place anyhow.

photo by brunox
Photo by Brunox983

Crop Sensor Calculator And Further Resources:

  1. Digital Camera Sensors Explained
  2. Crop Factor Explained: How Sensor Size Affects The Field Of View
  3. These Are The Reasons Photographers Should Give The Square Crop A Chance
  4. What To Expect From A Cropped Sensor And A Full Frame Sensor
  5. Does A Cropped Sensor Matter Compared To A Full Frame Sensor?
  6. How Does Your Camera’s Sensor Size Affect Your Photographs?

Further Learning:

It could well be a good idea to ensure you're covered when it comes to knowing how your DSLR works and learning some Essential Photography Skills. That's where this easy step by step guide for beginners is a great place to start.

About Author

Russell is a self-taught photographer who loves travel and capturing life as it unfolds. Having lived in the far east for a few years with some long term travel, this catalyzed his new-found passion for photography.
Lifestyle, Food, and Event Photography are areas he enjoys most.

Since I’m fantasizing about Fuji’s GFX50, can we coin phrase for going the other direction? How about “enlargement factor”?
Full disclosure: The above is intended in jest. (Just in case)

Thanks. I could do the focal length calculation. But although I knew there was also an f-stop difference, this is the first time I’ve seen a way to calculate it. I entered some lens info and got the hard numbers that confirm why I’ve been unhappy with most images from a couple of shoots.

There’s a colorful event in a local arena that I’ve shot a few times (for fun, not professionally). The place is old and has awful lighting. Although the dancers in the arena are colorful and interesting, and with a pass you can shoot from the floor level, the backgrounds are cluttered. I’ve never been happy with my images from an APS-C camera with a good f4 telephoto. The problem is, that I need more bokeh and less of the distracting backgrounds. This year I am *finally* shooting it with a full frame sensor camera and an f2.8 telephoto. If I don’t like the images using that setup, it will be down to me and not the equipment.

As I said, the calculator shows me the hard numbers in the f-stop equivalents, and honestly given those numbers I’m less unhappy with the DOF I got in those photos because, well, the numbers seem quite credible.

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