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Showing results for tags 'crop'.
...and a Speedbooster! I'm trying to wrap my head around what the mathematical formula must be to gauge how wide/zoomed lenses will be on a GH4 with a Speedbooster. What I know so far: - Shooting 4K, the crop is 2.3 - Shooting 1080, crop is 2.0 - Metabones Speed Booster lessens crop by 0.71 - Generic Speed Boosters lessen crop by 0.72 Is the math: " FF LENS x CROP x BOOSTER ="? or for a 18mm lens: 18mm [Lens] x 2.3 [4K Crop] x 0.72 [Metabones] = A 29.808mm lens equivalent? To make matters more confusing to me, that only covers full frame lenses, so how do we determin
The Northrup video (thanks KarimNassar for posting) got me thinking about the following math to match a crop sensor to an FF sensor camera (this was also helpful: http://www.josephjamesphotography.com/equivalence/#introduction ): Multiply the focal length by the crop factor Multiply the f-stop by the crop factor Divide the ISO by the square of the crop factor The first two equations deal with the difference in scale. The physical aperture (light opening, "entrance pupil") will be exactly the same: Given: f-stop = focal-length/aperture-diameter aperture-diameter = focal-length/f-stop
Many people find that a 2x (3.55:1) aspect ratio is just too narrow for their liking. The good news is that if you are using a 2x lens and you have a DP4 monitor, you can compose and shoot in 1.5x. This allows us to enjoy all the benefits of 2x glass (greater availability, lower prices, more dramatically stretched bokeh) with none of the headache. Here's how to do it:[list=1] [*]Choose a Preset number so that you don't have to make these adjustments every time (just scroll back to the Preset). [*]Under the [i]Advanced Menu[/i], go to [i]Scale[/i] and select [i]2.35:1[/i].
[url="http://abelcine.com/fov/"]http://abelcine.com/fov/[/url] Here's a useful tool to help with focal length decisions, when comparing sensor sizes. It might be worth a pin, as I'm always popping back to it! Blackmagic Cinema Camera is included. JG