Sony A9 vs RIV in terms of reach

[Tpap]

Quick question:

Sony A9 and RIV both with 200-600 sony lens.

If you take a photo of a bird with both cameras with same settings and crop down to APS-C with the RIV vs use a teleconverter on the A9, which will be the better photo?

I know it depends on light and many other factors, but I have had both cameras and I know the RIV at anything higher than ISO 3200 is not great and especially when cropping into the frame it gets worse.

The A9, 200-600 +1.4tc combo would give 24mp 840mm focal length f/9 vs the RIV without tc would give f/6.3 at 600mm but when cropped in to APS-C would this lead to an equivalent image in terms of noise/quality etc, or would it be better because the main photo was taken at a more open aperture?

Thanks for your help in advance, it is kind of a tough question to word.

 

[Garfield]

I don't shoot Sony but a quick glance at the camera specs indicate the A9II puts 24MP on the "duck", while the RIV cropped to APS-C puts 26MP on the duck, so the RIV wins *IF* we ignore a whole host of other factors such as the image quality differences at the pixel level (i.e. signal-to-noise-ration/DR) due to different pixel well size, differences in sensor design/AA filter impact, the impact of the teleconverter etc.

If the light was good I'd give the nod to the RIV due to the few extra pixels, the elimination of the TC in the optical train and the lack of an AA filter. Once the light starts dropping, I expect things to get complicated.

 

[arbitrage]

Garfield's reply is spot on. There are a lot of complicating factors because in one case you end up with 26MPs but those are small APS-C sized pixels vs 24MPs that are nice big, fat FF pixels. I'd much rather end up with a 24MP FF vs 26MP APS-C IF the optics and f-stops/ISO needed to get there were equal. But in this case we have to consider what the TC on the A9 adds to the equation with the stop of light loss (higher ISO to compensate?) and some IQ degradation from the TC itself.

It is a tough question to answer and owning the A9II, A7RIV, 200-600 and 1.4TC I'm never quite sure which is best.

One other thing to consider though is the 200-600 doesn't play nicely with the A7RIV. Many people including myself have had inconsistent AF with that particular combo. Now with newer FW and certain settings I do trust the combo a lot more than I used to. However, I trust the AF of the A9II with the 1.4TC on more than I do the AF of the A7RIV without the TC.