one eye jack
Senior Member
@Pitachu, AI answer to focal length and "effective" aperture...
- Not a Direct Measurement:
The f-number doesn't directly tell you the diameter of the lens's aperture in millimeters, but it's a way to quantify the aperture size relative to the focal length.
The f-number is the focal length of the lens divided by the effective diameter of the aperture. So in the case of the 35 mm F1. 4 G lens, when the aperture is set to its maximum of F1. 4, the effective diameter of the aperture will be 35 ÷ 1.4 = 25 mm.
By way of calculation eg. Om lens 800mm divided by 4.5 = 177mm or about 4.5 inch. Now I take it to mean the front objective lens that cover m43 sensor circle. Imagine if it covers full frame in which Signal 150 - 600 mm which in m43 equivalent 300 - 1200.- Your wish that Sigma reduce the front lens element to a smaller size does not compute unless you want an F11 equivalent. Just saying , not trying to be smart aleck here
- OMDS EM1X MK2
- You may not appreciate the monolithic construction of a pro body but it has their value eg. Although bulky and heavy it holds a bigger battery and therefore would last a day's shooting. For video the original OM1X has no overheating for video use as the body acts as a big heatsink. Again whether OMDS want to compete head to head with the big boys like Sony, Canon and Nikon depends if there is a viable business market share but the odds are stacked against OMDS because most professionals do not change systems as they have invested in proven and reliable cameras plus the inherent bias of full frame.
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