RF 100-400 or Sigma 150-600 for plane spotting?

Hello

the Autofocus has a limit speed when tracking fast objects, which is between 5 to 75km/h depending on the quality of the Objetiv (My employer uses 2 linear slides in a 1NM light tunnel, each has 55km/h V Max you can measure up to 110km/h).

If you take an airplane 90° to the direction of flight, it is fast at the start run between 50 – 350km/h but the speed is 0. In this respect, the classic planespotting does not require a autofocus when panning.

In the case of aerobics or even Red Bull Airraces, the aircraft flies at all possible relative angles to the photographic standpoint at speeds which are faster than the autofocus motor can regulate.

The basic rule for autofocus optics is the less the optics costs the slower is the autofocus. Except for Canon, all external optics will be burned at mid-class speed even if the zb to Nikon, Pentax or Sony focus quickly. That’s why Canon photographers always work with Canon in the sports field, it makes no sense to mount a braked Sigma, Tamron, Tokina optics on Canon cameras it only makes “Sinn” at Nikon, Pentax, Sony without OEM forced chip.

You bought an Eos R100 so the slowest “Bodensatzkamera” of the Canon R system and now the slowest Eos R camera that focuses quickly with EOS R or Canon EF Ring USM optics. But this is not a topic in planespotting, the subject is so slow that the R100 is completely sufficient.

Now you’re looking for a local road transfer on a highway with camera and optics, turning over a road to 400mm and letting AFC lock on a truck at about 1km distance. 400mm focal length has the truck driver’s cab at 1km by 40×60 meters object field, which is filled by 2.5 x 4 meters, so just as selective measuring circuit.

Trucks are usually on flat BAB lines with 87km/h (compulsory throttle, above which the driver’s license is gone). The truck is on the 0° axis to the camera now you’re catching the middle and zoom on closer to it slowly so that the cab stays in the frame until it’s “faster” than the focus motor. You write the distance. Then you go about 10 meters to the right or left so that the trucks are still under the 5° axis in 1km distance and repeat the same and write it up. You do the whole at 10/20/30/40/50/60/70/80/90/100 meters.

Then one takes a caro paper and carries on one axle the limit speed of the autofocus in meters, on the other axle, because the panning angle to the roadway axis and usually gets a dog line curve (Y=mx+b). The same test and the same data sheet are made for the next optics.

With the data sheet, you can compare the limit speed of the optics when panning constantly fast objects, and you know as a photographer zb during a motorsport design or in an airrace at the Wendepylon where you have to stand up so that the autofocus will still remain on the target without “decreasing”. The curve is always more and more slower in cycling or athletics the real speed is the closer you can get.

The point is at Airraces and Aeorbatics the aircraft are “deep” and relatively close and thus faster than the autofocus motor. High Areobatics over 200 meters pack most Autofocus mid-range optics after 2000. Among these you need a sports optics/professional optics and since Ramstein there are minimum distances to the audience and the audience must not be overwhelmed, so at events you are always in the pannig mode. Before Rammstein you went with xx-300 Telezooms on airshows and then the first light/carryable xx-400 zooms came. In principle, you have reached 200mm. Ramstein needs at least 400mm