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A700 vs A900 vs A77 autofocus

adakshi

New member
I have A700, using it for almost 3 years. I am quite happy with it except Focus accuracy. Even with my 70-200G and using central double cross AF point in AF-A or AF-S, I miss-focus in broad daylight(3 out of 10). This is worse with other lenses like 50 1.4 and 135 1.8. Using outer AF points is more prone to miss focus. Low light situation is pathetic, I can't use outer AF points with my 135 1.8 at all.

Also I find AF speed is sluggish in AF-C, unless I use SSM lens.

My daughter has turned 2 and if I need to capture right moments I need a reliable and fast AF. I understand no camera can give me 100% success rate, but A700 is definitely not up to that work.

I am thinking of upgrading to A900 or A77. I'd like to know your opinion about A900 and A77 AF system. How accurate is AF system and how fast. Has anyone upgraded from A700 to A900 or moved from A700 to A77?

I really don't care much about noise. I rarely shoot higher than 1600 and if I am printing real BIG, probably those are landscape shots taken at ISO 200.

I read many reviews about SLT vs SLR, I personally prefer SLR but AF accuracy and speed is more important to me.

I'll either move to A900 or A77 or if nothing works in Sony world, I'll be forced to move to other system, but that would be my last option.

Appreciate your help.
 

Mark K

New member
A900 should be similar to A700 with regard to AF. I have A850

A77 is snappier...and faster. Accuracy is another thing. A77 does hunt, though in another way. I can't really describe the the difference.

For moving subjects especially animals in the wild, both A700/A900 are not up to the job.

As far as image quality is concerned, A900 has no comparison in alpha mount at the moment. A77 has better image quality in lower ISO however, it is getting noise even at iso 320.
After proper post processing, noise should not be an issue.
This is from A77
 

Bill Caulfeild-Browne

Well-known member
I have an a900 which I generally use with the ZA 24-70 lens. I used to have an a700 but sold it in favor of the a77 - which I generally use with the 70-400 G for wildlife. I find the a77 autofocus significantly better than the older "a"s.

Because of its lack of a mirror the a77 tracks moving subjects much better too. I find it ideal for wildlife. I think you'd notice a distinct improvement over the a700.

Bill
 

dhsimmonds

New member
I agree with Bill's comments. I have used all three, A700,A900 and now the A77 all mainly for wildlife photography with longish lenses , usually the 70-400G.

I have now relegated the A900 as a back-up for my A77 which seems to have the 70-400 permanently attached! My A900 usually has a wider angle zoom fitted and within reach when on location as these damned critters can sometimes surprise me and come real close, then the A900 and wider lens is all set up to go! It makes for a great wildlife outfit. :D
 

adakshi

New member
Thanks everyone. Finally I bought A900 and A77 both. No not for testing, I plan to keep both and sell A700.

I think I got rid of the miss-focus issue of A700 by blowing air near to AF sensor area. I think I had dirt or something there and my A700 is working fine now. With A900 and A77 I get AF micro adjust feature and all my lenses are super sharp now.

I am impressed with A77's AF speed but I think A900 is more accurate with the central AF point. I took a couple of pics of water scooters moving randomly, well those are big objects in water so no cam should have any problem focusing. Still I got 100% success with A900 in AF-C mode with center AF and each image is tack sharp. A77 was quicker to focus but not that accurate plus noise is a big problem for A77. I don't get the sharpness once I go past ISO 400.

All these images are from A900 and 70-200G lens

[/url] DSC00017_DxO by adakshi, on Flickr[/IMG]


DSC00018_DxO by adakshi, on Flickr


DSC00033_DxO by adakshi, on Flickr
 
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