Question or opinions about upgrading: A99 or A7R?
Background: I currently own an A77 with some good A mount lenses, and although I am not technically a professional, I create professional level images and am moving forward to making this my career. I am interested in doing advertising and event photography (not including sports), and will undoubtedly continue with weddings and portraiture.
My priorities in order of relevance, all are important:
1) Durability and long term cost effectiveness.
2) Focus speed and accuracy.
3) Resolution (although I feel 24MP is acceptable, 36 would be nice. More is unnecessary for my needs.)
4) Low noise issues at all ISOs, and low light performance.
Video performance is not currently on my list of concerns, I can address that in the future if I find myself going in that direction.
The A99 has A-mount (which is all my lenses) and is a very good camera, but showing its age a little at 3 years old. The advantage is that I will have better focusing capabilities and way more lens selection, in addition to using my A mounts natively, which I think is a better mount because, by virtue of size, it allows for larger apertures. The drawback is that it's an SLT meaning that it's mirror lets most of the light through while using a little reflection for focusing and metering. Great camera though.
The A7R is much newer and uses an E mount lens. I can get an adapter to use all of my current lenses but will lose focusing speed and precision unless I invest in the (as of now) limited and expensive E mount glass. It is a lot newer and has some amazing features, but the biggest difference is that it is mirrorless. Focusing is slower but still acceptable for most shooting. It has a higher resolution (36MP vs 24MP) but this is not much of an issue as 24 is plenty for pretty much every print I will make. Low light shooting is better, and its much smaller, and has wifi and Bluetooth technology so I can upload immediately to social media. Also an amazing camera.
Which direction do I move in? Stick with the A mount and have better focusing ability or go with the E mount and gain a little resolution and technology? There are other concerns too like battery life and memory but these are not as important to me.