[toni-a]

I am hesitating which one should be my next uprade.

I already have 30D and 5D MKI and I think both full frame and APS-C are equally good.

Which one should be better especially at high ISO 

I don't do sports but I need deadly precise autofocus for portraits.

 

 

[thxbb12]

If you shoot mostly portrait, FF makes more sense IMO.

 

Now, if AF accuracy for is your main concern, you should consider mirrorless instead. AF accuracy is much more reliable and accurate than any DSLR. If portrait is what you're after, you should strongly consider Fuji (the 56 f1.2 and 90 f2 are fantastic portrait lenses).

[davidmanze]

  For the most part the studio industry in it's 24X36mm DSLR form was mostly shot on the 5DMkIII...........

[joachim]

If you shoot mostly portrait, FF makes more sense IMO.

 

Now, if AF accuracy for is your main concern, you should consider mirrorless instead. AF accuracy is much more reliable and accurate than any DSLR. If portrait is what you're after, you should strongly consider Fuji (the 56 f1.2 and 90 f2 are fantastic portrait lenses).

Another vote for mirrorless here if AF accuracy is a concern. 

 

Fuji cameras and lenses are very tempting.  As I know from my X20, the in camera JPEG engine and in camera editing function is a big time saver.  I am sure the lenses names above are very good.  Unfortunately they are also very expensive.

 

The non-existence of a more economic alternative with fast AF made me stay with Olympus when I last upgraded.  From a price/performance perspective the Oly 45/1.8 must be one of the best buys out there.  As far as I can make out the compromises are poly-carb outer shell (have yet to see any report on that lens falling apart for that reason) and that it is f/1.8 and not f/1.2.

 

Another aspect is size.  SLRs and the matching lenses are typically on the big site of things.  A smaller mirrorless is less intimidating. 

[Brightcolours]

If you shoot mostly portrait, FF makes more sense IMO.

 

Now, if AF accuracy for is your main concern, you should consider mirrorless instead. AF accuracy is much more reliable and accurate than any DSLR. If portrait is what you're after, you should strongly consider Fuji (the 56 f1.2 and 90 f2 are fantastic portrait lenses).

Your AF ideas about DSLRs live in the past still... The 5D mk III is very capable of focussing accurately with very shallow DOF. And fast at that.

 

Toni-a, I forgot which lenses you have. Of course, lenses play a big part in the result. For portrait, FF makes more sense unless you never use shallow DOF in portraits.

[joachim]

Your AF ideas about DSLRs live in the past still... The 5D mk III is very capable of focussing accurately with very shallow DOF. And fast at that.

 

Toni-a, I forgot which lenses you have. Of course, lenses play a big part in the result. For portrait, FF makes more sense unless you never use shallow DOF in portraits.

 

There is shallow, very shallow and extremely shallow.  On my books a 90/4 (equivalent) is between shallow and very shallow.  This typically leads to one eye being out of focus, so one has to pick the "leading eye" with the AF or hope for the face detect to do that for you.

 

Coming from µFT with its pretty efficient face detect (incl. eye priority) I am honestly wondering how one would do that on an SLR when using a finder.  I understand these don't offer eye detection when not in a "live view mode".  Background: I am chasing toddlers with a 45/1.8 (90/3.5 equivalent) in lowish light (ISO 1600, 1/60s, f/1.8).

[Klaus]

If you need ultra-high ISO then mirrorless is not for you.

That's not because of sensor noise (the Sony A7s would rule them all here) but in terms of AF.

Contrast detection AF is much more accurate than phase-detection AF on DSLRs but this advantage fades towards very low light.

But that depends on the amount of light we are talking about here.

 

The question of the day is however ... why do you want to upgrade at all ? :-)

[JJ_SO]

No matter how advanced DSLR AF might be, I always struggle with focuspoint being on the wrong place. If I do portrait I change composition a lot. I don't do one composition and dozens of facial expressions. So I need to navigate this bloody AF points quite a lot. That's a slow process and influences framing all the time. Due to field curvature of some lenses, outside AF points are sometimes less precise wide open. Also, while trying to focus the eye I sometimes lose the composition - sharp eye, poor framing and not always possible to correct in post.

 

So, I'm more than ready for a good quality mirrorless with well performing eye-detection AF because I know, in sufficient light I'd get more keepers. And in insufficicent light? That's a gambling even with "advanced DSLR AF", because only the center points and some horizontally and vertically crossing the center points are highly sensitive. The majority of those 51 points are not much of a help = keeper rate goes down. As long as I don't try a contemporary mirrorless, I can't judge which system is better for me.

 

As a sidenote: I'm going to replace my Canon G10 with another compact for all the moments when I just want a responsive camera with me, no lens-change and everything I need on board. I was looking first at Sony RX100 mark IV and because it was in the shelf, too, also the Canon G5X which is a bit bulkier, less pocketable. I can't judge IQ but easy to use was the Canon - and the AF very snappy, I liked that a lot. I know  the IQ won't be best in the market in this class. Small sensor, high MP. But dials, buttons and finder (especially EVF quality) was like made for me. Weak point of the Sony: The menu, missing touchscreen, tilt-only, not swivel display. And when the EVF comes out, you still need to pull a part of it backwards. Fiddly.

 

Maybe you should wait, toni-a, until Canon brings a mirrorless FF.

[thxbb12]

Your AF ideas about DSLRs live in the past still... The 5D mk III is very capable of focussing accurately with very shallow DOF. And fast at that.

 

Toni-a, I forgot which lenses you have. Of course, lenses play a big part in the result. For portrait, FF makes more sense unless you never use shallow DOF in portraits.

 

My idea about AF accuracy is very much in the present.

If you understand the AF technology behind CDAF vs PDAF (through a separate AF sensor as in a DSLR) you would know your statement doesn't fly.

Shooting the 56mm at f1.2 on Fuji is a non-issue, which is something none of the DSLR shooters can say when using their 85 f1.2 or f1.8 lenses.

Everyone who used a good mirrorless system will tell you exactly the same.

DSLRs are great at certain things, but AF accuracy is definitely not one of them.

 

Since I know you're gonna come back with some silly rebuttal, here is what Nasim Masurov from photographylife.com, who is not exactly someone without DSLR experience, said about AF in his review of the Sony  A7RII (link to the review here):

 

How does it compare to DSLRs? When it comes to AF speed, the best lenses on DSLRs feel a bit faster in comparison, but for the most part, I would say that the AF speed is comparable. However, when it comes to focus accuracy, the A7R II is absolutely amazing. In fact, looking at the images I have captured with the A7R II and my Nikon DSLRs, I am yet to see an image that was poorly focused on the A7R II and I sadly cannot say the same thing about my Nikon DSLRs. One of the main reasons for such superb performance is phase detection built directly on the sensor, instead of a secondary sensor sitting on the bottom of the camera chamber in DSLRs. Phase detection with a secondary mirror is prone to all kinds of issues and if any of your lenses are not in sync with the camera, even a detailed calibration process can result in inconsistent AF behavior. There are a number of problems with lens calibration – you cannot save adjustments at different distances (adjustments often vary quite a bit with distance) and you cannot save adjustments at different focal lengths. Mirrorless cameras are immune to such focus issues, because the image is projected directly on the image sensor and there in no separate focus system. If there is a phase detection system present on the camera (as in the case of the A7R II), since the phase detection pixels sit directly on the sensor, what you see is basically what you get. Another reason for such superb accuracy is the new AF system on the A7R II – it just does a great job at nailing focus, especially when you photograph people. The camera is smart enough to track faces and when you track the subject with the Eye AF feature, it does a phenomenal job at continuous AF adjustments, keeping the eye constantly in focus at varying distances. To date, I have not seen a single DSLR that can track subjects as well as the A7R II does, which shows just how good the hybrid AF system on the Sony cameras has gotten lately…

[Brightcolours]

My idea about AF accuracy is very much in the present.

If you understand the AF technology behind CDAF vs PDAF (through a separate AF sensor as in a DSLR) you would know your statement doesn't fly.

Shooting the 56mm at f1.2 on Fuji is a non-issue, which is something none of the DSLR shooters can say when using their 85 f1.2 or f1.8 lenses.

Everyone who used a good mirrorless system will tell you exactly the same.

DSLRs are great at certain things, but AF accuracy is definitely not one of them.

I understand AF technology just fine. So, which present are we talking about? Have you used any of the current Canon DSLRs for instance?

It is nonsense to say that shooting the Canon EF 85mm f1.2 or 50mm f1.2 or 200mm f2 or 300mm f2.8 are giving issues with F with the current Canon bodies. It is fine for people like you who use a mirrorless camera to say it is an issue, but it is not based on much.

 

Sorry that your Pentax DSLR experience has been such a downer.