Swedish FOTO finds A580 faster than Pentax K5

[David Kilpatrick]

Though FOTO (which use the former Hasselblad/Zeiss testing facilities) rated the K-5 as a topklass camera and the A580 as just recommended, the focus and shutter timing figures were interesting.

Resolution for the A580 was given as 2650h 2650v with the CZ 16-80 at 35mm and f/5.6 (the Nikon D7000 managed 2700 on the horizontal reading, but that was with a Sigma 18-50mm f/2.. The Pentax K-5 achieved 2650/2600 with a 17-40mm f/4 SDM aet to the same - I don't think these tests are very fair, as the Pentax and Sony lenses are used 'one stop down' at 35mm but the Sigma lens is two stops down, and in my experience that tends to be a sweet spot with such lenses - rather than just f/5.6 always being optimum.

For focusing, the K-5 test produced 0.25s at 17mm, 0.30s at 35mm, 0.35s at 70mm, and a shutter delay time of 0.10s. The A580 gave 0.22s at 16mm, 0.28s at 35mm and 0.48s at '85mm' (impossible of course as the lens only goes to 80mm), and a shutter lag time of only 0.06s.

The only significant difference is that the Pentax lens is equivalent to SSM, while the Sony lens used is screw drive.

Both Pentax and Sony came out significantly worse than the Canon 60D and 550D with which they were respectively compared, for focusing speed - the Canon USM generally manages either 0.22s all round, or 0.22/0.23/0.25 for the 550D. The 60D has the same 0.06s shutter lag as the A580, the 550D has a longer 0.10s similar to the Pentax. The Nikon D7000 has focus speeds of 0.28/0.35/0.37 (very comparable to Pentax, slower than Sony at wide to normal angles, faster at the long setting) and an extremely fast 0.04s shutter lag.

The magazine described the A580 as a very fast reacting camera - 'en reaktionssnabb kamera som klarar sig bra i konkurrensen' - and as being 'at top of its class along with the Canon 550D' at the wide angle setting tested.

David

[bakubo]

Everything I have seen and heard is that the A580 and A55 are really good and Sony has done some good work on AF, low noise, dynamic range, etc. That is great news. It will be interesting to see what comes in the future.

I have never been one to care much about brands so in the future if Sony has something interesting then I will seriously consider it when I am ready for a new camera. Darn, if Crocs or Nestles came out with a new camera then I would consider them too -- especially if they used either the A mount or Canon mount since those are the ones I have some lenses for.

[peterottaway]

And how did the A 580 test against sub $ 800 Nikon and Pentax cameras ? Especially using the same third party lens.

[David Kilpatrick]

I don't keep my back issues of FOTO - sadly, they charge 15 Swedish kroner for each PDF test download...

http://www.tidningenfoto.se/Sites/Foto/ ... 23288.aspx

David

[bfitzgerald]

I remember making a reference to Imaging Resource and their AF tests and it being said (fair point) that you can't really compare in lens motors to screw driven ones. This might make a Canon comparison difficult (unless you use a lens that has an in lens motor) so what we have here is pretty much the same thing if not worse they are not even the same lenses..we need a consistent and objective result this tells us very little.

Pentax are known to have problems with SDM speed has been mentioned more than a few times and reliability an issue it would appear.

Using their cheapest DSLR the K-x there is nothing slow about their AF at all it's very fast (screw driven lenses) Not used an A580 so cannot comment on that.

[bakubo]

I have been using the Tamron 18-270mm (not the new PZD version) on my Canon 60D now for the last couple of months. The old Tamron 18-270mm got hit for slow AF in some reviews and forum comments, but I also had the Sigma 18-250mm and Canon 18-200mm to compare it to on the 60D and found that it was only about a half a step slower than those 2 lenses. To me it seems fine and even with servo mode was able to track fast moving bodyboarders -- although they weren't so close -- and that is something my A700 and Sony 18-250mm couldn't do. The main reason the AF with this lens is acceptable to me is because I used the A700 and Sony 18-250mm for almost 3 years and that combo is much slower, so it really depends on what you are accustomed to. When using single shot AF mode on the A700 + 18-250mm if the subject distance you want to focus on is not much different than the current focus setting then the AF is pretty fast, but if there is a big difference (such as focusing on something far away when the current focus setting is very close or vice versa) then the body/lens seems to go into a completely different AF mode which is very slow. The 60D + 18-270mm is as fast when focusing on things that don't vary in distance much, but when they vary a lot the AF is not nearly as slow as the A700 + 18-250mm.

The word is that the new PZD version is a lot faster, but since the current version seems to be faster than what I was used to before that is not enough of a reason for me to change at the moment. The smaller size and lower weight is attractive though since the new version is almost the same size/weight as the Sony 18-250mm. I will wait until it has been out longer and I see some reviews before deciding -- and maybe the price will drop some by then too.

[David Kilpatrick]

In fairness Henry the 18-250mm whether Tamron or Sony is not practical for following focus. The A700 fitted with a Sigma HSM 70-200mm or 18-250mm is a completely different camera and tracks moving subjects using single AF point about as well as the Canon 60D. The operation of the lens changes completely with SSM or HSM etc focus motors.

The difference is most noticeable with moving subjects, where the relatively fine gradual change in focus is handled very well by the in-lens supersonic motors. They are not much faster, and may even be slower, for making single big changes in focus. It's the tiny increments and progressive changes to follow movement which are transformed.

David

[bakubo]

In fairness Henry the 18-250mm whether Tamron or Sony is not practical for following focus. The A700 fitted with a Sigma HSM 70-200mm or 18-250mm is a completely different camera and tracks moving subjects using single AF point about as well as the Canon 60D. The operation of the lens changes completely with SSM or HSM etc focus motors.

The difference is most noticeable with moving subjects, where the relatively fine gradual change in focus is handled very well by the in-lens supersonic motors. They are not much faster, and may even be slower, for making single big changes in focus. It's the tiny increments and progressive changes to follow movement which are transformed.

Yes, I was trying to be clear that I was only talking about the 2 lenses and 2 bodies that I mentioned. I know that with other lenses things would be different. Actually, the A700 + 18-250mm AF was mostly fast enough for me. Even for shooting bodyboarders or surfers I prefer to use single shot AF mode and never use continuous advance. Just for grins I tried servo mode on the A700 and 60D with the respective lenses a few times each though just to see how they would do. The Sony 18-250mm when racking all the way in or out though did occasionally cause me to lose a shot because it was sooooo slow, but not often.

[Edgars L]

In PopPhoto AF speed tests A55 is for 25-30% faster than Nikon d7000.

http://www.popphoto.com/reviews/cameras

[bfitzgerald]

I ran into a pal who just bought a D7000 yesterday and I had a grab for a few mins nice solid body..don't like the layout and ergonomics though (ISO and WB in the wrong place, metering button wasted in that location) I've news the AF isn't really "that fast" def nowhere near Canon 7d levels. Hard to compare with different lenses but Nikon just don't have a rep for "breakneck AF speed"

Of course that does not mean their accuracy isn't pretty good.

Sony are notoriously weak for outer AF points just as Minolta were those single line sensors just don't really cut it in 2011. I bet a lot of A mount users are using the central AF point mostly and in dim light you can really struggle with the outer ones.