On this app, I could only key in the focal length. Tapping on 'Sensor' and 'Aperture' just shows a blank pop-up, hence rendering the app rather useless.
4 people found this review helpful
January 9, 2019
Hello, the hosting company that mmCalc uses encountered a massive outage on January 3rd to 5th 2019. We have since moved away from this host due to their error. Please try the app again, you should no longer have an issue.
Can't give a good rating because crop factor does not affect fstop. Happy to change my review if/when this is corrected. Focal ratio is a relationship of physical parameters, which are not altered by crop factor. In other words, the actual physical focal length is the same in a crop sensor camera, the angle of view is narrower AS IF the focal length was longer. Of course - it is not physically longer, so the f ratio remains the same. Let's nip this unscientific myth in the bud eh?
1 person found this review helpful
November 8, 2021
Crop factor actually does impact the perceived f-stop. The lens regardless will always let in the same amount of light but the actual depth of field will overall be less as you will have to reposition your shot due to the crop. This is explained in the app when you run a calculation.