5Ds focus mode for portraits?

Hello Guys/Girls,

So finally its Christmas, and I got my present, the EOS 5Ds (and a 85mm1.2L).

This new autofocus system is new to me, and I would like some advice.

What focus mode (Spot Af, 1 point Expanded to 5, expanded to 8, Zone AF), are you using to achieve the best results?
I would say, spot AF sould be the most accurate, but I am unsure.

Any Advice?

Thank you very much, and Happy Holidays to all of you!

They are all accurate to the same level.
But spot AF is the most selective, and can be useful to set focus on small things, like an eye. The more AF Points you involve, the broader the view is to the AF system. It's still equally accurate, but it may of course select to focus on a part of the subject for which you don't care the same as the AF system does.

Generally, for things standing still and where you really care about where to focus, use a single point or spot AF.
When things are moving too fast for you to keep a single point on the target, make the AF point array you use wider.

I don't know didly about portraiture but wouldn't you make sure the DOF is great enough to cover everything?

Well I asked about focus mode, not DOF, but to answer your question, no i would not, I want the 2 eyes to be sharp, in a portrait, if the ears are not so sharp, its not an issue for me.
If they are, that ok, but its not a must.

Yes, that's another issue. Depends entirely on how you want the portrait to look.

DOF will play a role, for example if both eyes are not in the same plane. At f/1.2 the DOF depth is so thin, if you focus on one eye, the other eye will not have the same focus if your subject's head is even slightly turned. The 85L is famous for that, great bokeh but you've got to coordinate focus point and DOF to get your intended results. If you are off, the 5DS will only accentuate any error. The 85L also doesn't have IS, so you are going to have to keep your eye on your shutter speed, even on a tripod. The 5DS and 85L can be a fantastic combo, but you are going to have to work for it. Practice, practice, practice.

John_T wrote in post #17831848
DOF will play a role, for example if both eyes are not in the same plane. At f/1.2 the DOF depth is so thin, if you focus on one eye, the other eye will not have the same focus if your subject's head is even slightly turned. The 85L is famous for that, great bokeh but you've got to coordinate focus point and DOF to get your intended results. If you are off, the 5DS will only accentuate any error. The 85L also doesn't have IS, so you are going to have to keep your eye on your shutter speed, even on a tripod. The 5DS and 85L can be a fantastic combo, but you are going to have to work for it. Practice, practice, practice.

Using a 5DS will make no difference to the DoF than using any other 36×24mm format body. Sensor resolution has zero effect on DoF, remember that to compare DoF you have to use the same size final image. Using 100% or 1:1 view on a computer screen is not the same size for images with different numbers of pixels.

Alan

...think you missed the point. He is interested in focus, and I am pointing out that in many situations, especially with thin DOF, you have more to consider than just the single focus point. Further, the 5DS resolution will accentuate OOF as well as any camera shake. Ask me how I know.

Sorry if I derailed your topic.

You didn't derail it. The two subjects are very closely related.

I don't have a 5Ds, but assuming the focus system is similar to the 5D3, I almost always just stick to single point autofocus. Single point seems to work quicker and better than any of the other modes, especially in low light. It should give good results for portraits.

As far as I know the other modes, zone focus, expanded single point, etc, are mostly intended for sport or fast moving subjects such as wildlife. I shoot quite a bit of sport and, for me, I still prefer to use single point. Mostly because I find it faster but also because I like to see exactly where I'm focusing. I'd guess I use single point for more than 95% of pictures and think it should work well for you too.

Nice Christmas presents!

John_T wrote in post #17831865
...think you missed the point. He is interested in focus, and I am pointing out that in many situations, especially with thin DOF, you have more to consider than just the single focus point. Further, the 5DS resolution will accentuate OOF as well as any camera shake. Ask me how I know.

I'll guess you know because you looked at 100% view on screen or made a bigger print than with your previous FF cameras

I use spot AF on the 5D3 works well but more and more using Manual AF and the live view for portraits.

Single point for me.

AJSJones wrote in post #17832271
I'll guess you know because you looked at 100% view on screen or made a bigger print than with your previous FF cameras

Yes and no, but mainly because I've had the 85L for ten years or so and it will challenge you almost more than any other lens in placing the focus and getting what you want of your subject within the focused field and the background nicely blurred.

I'd recommend starting with the 85L at f/5.6, single point focus, then work your way down to the larger apertures/thinner DOF.