In part one of the series the accessories and features of the entry level full frame EOS 6D and Nikon D600 were covered, and in part two full frame lenses were covered. In this third installment we'll look at why users of cameras like the D300(s) and EOS 7D might want to consider moving to the EOS 5D MKIII and D800, rather than the entry level full frame models. While the higher end full frame models are more expensive than the entry level models, they do offer more advanced features that might be helpful. Before you decide what direction to go, if you move to full frame, it might be worth looking to see if the higher end models have features that you need, and if they are worth the extra expense.
If you are pondering the move to a full frame camera you are committing a lot of funds to this move, between the camera body, accessories, and in many cases lenses. As part of that process you don't want to sell yourself short, so make sure you get what you need rather than settling, because if you under buy today, you'll end up spending even more if you find yourself needing to move up to one of the higher end bodies in six months to year from the time you make your purchase. The impact of the choice is long term, because it is not practical, or necessary, to buy a new camera each upgrade cycle. What you choose today could be in your camera bag for at least four years, or more, so be sure that you make the right choice the first time.
Why Should I Consider the EOS 5D MKIII or D800 over the EOS 6D or D600?
The following are possible reasons why current owners of high end crop sensor bodies, who are looking to get into the full frame format, should consider the 5D MKIII or D800, rather than the 6D or D600.
Between the entry level full frame models and the higher end models there are some differences in build quality. The high end models have full magnesium alloy frames, vs semi magnesium alloy frames in the entry level models. The difference between the 6D and 5D MKIII are less than the difference between the D600 and D800 in this regard. On the 6D the frame, other than the top plate is metal, while the 5D MKIII's frame metal all around. The D800 has a full magnesium alloy frame, while on the D600 only the top and rear plates are metal. This leaves the D600's lens mount into plastic, which might prove to be too much of a compromise, if you use heavy lenses without tripod collars (like the 24-70mm F2.8, 14-24mm F2.8 etc). Both the 6D and D600 are said to be water resistant to some degree, but I suspect that the higher end models have better seals in place. Having a solid metal frame also decreases the chance of moisture reaching the vulnerable electronics inside the camera body.
Auto Focus System:
The difference in auto focus performance between the higher end 5D MKIII and D800 over their lower priced rivals is easy to spot. Both higher end models feature a greater number auto focus points, more of which are cross type points for better sensitivity (particularly in low light). In addition the auto focus points of the higher end models are less cramped, and cover more of the frame, so you don't need to waste as much time focusing and recomposing. That last point will be of particular interest to anyone who shoots sports, wildlife or other activities with a lot of subject movement.
If you are coming from an EOS 7D or D300(s) then you will feel right at home moving to one of the higher end full frame bodies, while moving to one of the lower end bodies will feel like somewhat of a step down in terms of controls. There are some slight changes in buttons over the crop bodies, simply part of the modernization process, but for the most part not much will change by going with the EOS 5D MKIII or D800. One area that may be an issue for people who work with flash a lot is the difference in flash sync speeds between the entry and higher end bodies. The 6D's sync speed is 1/180s, and the D600's is 1/200s. Both the D800 (1/320s) and 5D MKIII (1/200s) are better suited to handle outdoor flash work.
The accessories you have, like cable releases, memory cards, and PC sync cords, to name a few, will still work with your new camera, if you go with a higher end full frame body. If you choose to go with the 6D or D600, you'll need to switch from CF cards to SD cards, while that is not needed with the higher end bodies which retain CF card support (note the 5D MKIII and D800's primary slots are CF, while the secondary slots are SD/SDHC/SDXC compatible). You might find yourself needing some bigger cards at some point, but you wont have to rush out and get them right away.
Some new accessories (batteries) will be needed in the move, regardless of whether you go with the entry level models or the higher end models, so don't let that hold you back.
If you are a demanding photographer, who wants to get a high quality camera that performs well over the long hall, make sure you pick the right camera for your needs, rather than just picking the lowest price full frame body available. There are some important differences in terms of build quality, auto focus, controls and accessories between the entry level models and the higher end models, and they need to be considered as part of the decision process. If you have to wait and save a little longer for a higher end model, it wont be the end of the world.
Are the features of the EOS 5D MKIII and D800 worth an extra $1000-1500 difference between the entry level EOS 6D and D600? That really comes down to the type of photographer you are, what you need, and what you can live with. Sometimes compromises are required, so take time to see if the compromises of the 6D and D600 are something you can live with or not.
Although not covered in this series, there are differences like amount of megapixels, this applies more to the D800 (36MP) vs D600 (24MP), and shooting speed, that also have an affect on performance. Those are very specific issues, shooting speed and resolution needs really come down to the individual users. The focus here was to show the common differences between the 6D and D600 vs 5D MKIII and D800, not nit pick at all the specs.
Next Wednesday I'll be wrapping up this series, with a post on why you might want to consider waiting to see what the next generation of high end crop sensor bodies are like before moving to a full frame body.