Why to choose A7/7r over A77 ?

Started Oct 17, 2013 | Discussions thread
EinsteinsGhost Forum Pro • Posts: 11,977
Re: Why to choose A7/7r over A77 ?

Abhayks wrote:

I currently have an A55 and am happy with it. However, its already 3 years old and showing age.

Planning to replace it. My choice was A77, but was holding on as the high ISO performance of A55 is better than A77. Now that A7 is released and in the price range, I am tempted to give in to Full frame and jump. However, there are various points which are stopping me from making the switch.

No 2.8 lens for A7 which can AF. Now I can use Sony A-mount 2.8 lenses but they will not AF and AF is a must ( for my skills) to shoot running / playing kids. I love the bokeh provided by my current Tamron 17-50 2.8. I can reuse this lens on A77 and still have AF. No such current option on A7.

You can use any of your A-mount lens on any E-mount body using LA-EA1, LA-EA2, LA-EA3 or LA-EA4 adapter. The first two are good for APS-c body only, while the last two are for FF (which would be the consideration for A7 or any E-mount FF body).

Of these, LA-EA2 (APS-c) and LA-EA4 (Full Frame) are SLTs. In other words, they convert the E-mount camera into SLTs so you get the same SLT based PDAF system. They also support AF for screw-driven lenses. The LA-EA2/LA-EA4 adapters actually use the same AF system as A55/A57 and A65, which is inferior to A77 but still excellent. So, LA-EA4 is your AF solution for A-mount lenses on A7. You also get AF Micro Adjust feature (A77 has it, but A55 does not), which can be useful if you encounter front/back focus issues with any lens. The SLT adapters are more expensive and bulkier, but do have an integrated tripod mount which is a wonderful thing with longer/heavier lenses without a tripod collar.

LA-EA1 (APS-c) and LA-EA3 (Full Frame) are mirror-less adapters. They too have a screw-in type tripod mount. They are cheaper, smaller and lighter. They do not support AF on screw drive lens. They will AF lenses with built-in motor (Sony SAM and SSM, for example). But, since the AF system is governed by the camera body, and A-mount lenses are not optimized for CDAF, the AF speed is slow. I would consider LA-EA3 (for A7) only for manual focus which may work better for macro, landscape and portraits but not for action.

I have tried A77 and its very quick to AF, much faster than my A55. Even with the limited lens available on A7, the AF speed is still in question. I have tried Nex-7 and its AF speed simply cannot be compared to my A55. If A7 is anything as slow as Nex-7, it'll be a disaster for me.

I've read that A7 is faster than NEX-7. So, a bit of that OS-PDAF may be at play, and if the lens involved was the 35mm/2.8, then it could also be that it is a lens designed for faster AF on A7 (smaller and lighter lens pieces). But, if you want excellent AF speed most of the time, SLTs can't be beat. A77 is one of the best out there. Sure you can convert A7 into an SLT with LA-EA4 and use any of the A-mount lenses for such occasions (I do that with my NEX-3), but A77 has a more advanced AF system than LA-EA4 and you also lose stabilization (unless you have an A-mount lens with optical stabilization, then you will have it). If you intend to shoot mostly action with A-mount lens anyway (as in my case), then loss of stabilization may not be an issue. I keep it off on my A55 anyway.

A key consideration may also be burst rate, which is slower on A7. Your A55 has two fast modes (10 fps with AF-C but auto aperture or AF-S/MF with aperture control and 6 fps with full exposure control and any AF setting), and A77 has 12 fps and 8 fps respectively.

  1. A55 and A77 are good to hold while the grip of Nex-7 feels odd. A7 is decidedly heavier than Nex-7 so should be having a better feel to the grip. But does it compares to the robust grip of A77 ?
  2. A77 battery will outlive A7 battery.
  3. The joystick on A77 proves much useful, not present on A7.
  4. On A77 I can use some cheap lenses like Sony 35 1.8, Sony 28-75 2.8 , Beercan and get very good result. The lens that can AF on A7 are very expensive and will increase my budget by a huge factor.

If you want to keep these lenses, you will be able to use them on A7 with A55/A57/A65 like AF system using LA-EA4. However, do note that Sony 35/1.8 is an APS-c lens, so either the A7 will crop the image or you may see vignetting that you may have to crop out.

  1. I can use my existing Flash F43 AM with A77.

If you want to keep your flash, but move to A7, Sony has an adapter to allow that. In other words, you will have to use the adapter (I think it is about $25). Or, you could replace the flash with the new ISO version.

  1. Tons of used lenses and accessories available for A77. A used Minolta 70-210 :F4 can be had for as little as $150-200 and is still an excellent lens. It has great AF on A77. These cheap options are un-thinkable on A7.

Beer can works great via SLT adapter (LA-EA4 for A7).

Considering all these options I am heavily inclined towards buying A77, well atleast that that my brain says. Not sure why my heart is fixed on A7 with the Kit Lens.

Its all about trade offs. With A77, you get APS-c (so a little more reach optically), and IBIS, and likely a good deal since the camera is about 2-year old in the market. It is a fantastic camera IMO.

With A7, you get a FF body, about the same size and (slightly lighter) weight as the A55 actually. And the sensor ought to be a gem but then, you do have some compromises.

Instead, if you can wait a few months, you might find A77 replacement to be more appealing, and it may even get FF sensor (if Sony is indeed going to use 7-series for FF as they have done with A7).

Would appreciate any points for an against A7/ A77. This will help me make the final decision.

 EinsteinsGhost's gear list:EinsteinsGhost's gear list
Sony Cyber-shot DSC-F828 Sony SLT-A55 Sony Alpha NEX-6 Sigma 18-250mm F3.5-6.3 DC OS HSM Sony 135mm F2.8 (T4.5) STF +12 more
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