I am sure quite a few of you are already hooked on Full Frame (FF) and feel APS-C is a bit of a backward step. But there are benefits, namely low cost and small size. However, there is another very important consideration: crop factor. however, this only becomes appealing if the full-frame lenses can lay down enough detail to make the smaller sensor sing!
If an APS-C camera can deliver great performance, it can offer us more reach on our long lenses, such as an effective 300mm at the long end of the Sony G 70-200 FE. With lenses like the new Sony Zeiss FE 16-35 f4, we would have an effective 24-52.5mm lens which starts to sound interesting if a person does not have 35mm and 55mm primes and wants to cover this range without purchasing the 24-70 f4 FE lens, which has some serious performance issues in the outer field and corners on the A7R and A7 FF bodies.
Here I am with native 35mm, 55 and 70-200mm lenses, but no stabilised lenses. I’d like a stabilised native lens because it would make my aerial project easier to shoot on the Sony bodies I prefer to use. I’ll have better ISO-Aperture latitude if I can drop the shutter speed a bit. I could buy the 24-70 f4, but I am not impressed with the reviews I have read and it’s not a cheap optic! I know I am going to end up buying the 16-35mm FE lens, so adding an APS-C body kills quite a few birds with one stone. I’m off to Iceland (again) in January and suspect having more than 200mm to play with will be useful, so I decided to have a quick look at APS-C performance with the lenses I have.
Without an A6000 on hand (or A5100 for that matter), I borrowed a friend’s 20mp A5000 and compared the files shot with the 35mm FE against 24mp shots form my A7 and 55mm FE combo. I chose to shoot at ISO 100 and 200, rather than higher up because I am not sure that A5000 compares to the A5100 and A6000 and higher ISOs. I was looking for ‘just an impression’ and I got one: the smaller sensor is superb and can easily stand up to the bigger sensor and longer lens. So what were the similarities and the differences?
Firstly the similarities: right away it was clear the same company made both cameras. Colour balance was identical, colour, contrast etc were absolutely from the same mould. Dynamic range appeared very similar, through of course we know the A7 tests out as having a little more (half a stop, or so). Resolution was interesting! I could see nothing more than what you would expect when taking a small increase from 20 to 24mp. They were almost identical. Towards the edges, it appeared that the slight field curvature from the 35mm meant that the 55mm A7 frames were a hair sharper, but at normal print sizes you’d be squinting to see. Bottom line: the 35mm and 55mm FE lenses lay down bags of detail for the high pixel density of the smaller APS-C sensor. I have no doubt whatsoever that the 24mm APS-C sensors would look all but identical in resolution with the 35mm to the 55mm and 24mp FF shots, with lens differences accounting for any observations.
What does this mean? Well, the 16-35mm f4 OSS seems to have stunning central performance and very good outer field performance. There is significant sample variation it seems, but it is clear that a good copy is a very good lens indeed. Well, with APS-C you get to take a nice central slice out of that very high-resolution central zone. Performance indications suggest that the Sony Zeiss16-35 FE is a good deal better in the outer field at 24mm than the Sony Zeiss 24-70 f4; however, I am going to venture that the 24mp APS-C cameras with the 16-35mm lens at 16mm (giving an effective 24mm) are going to perform considerably better around the edges than the 24-70mm, at 24mm, on the 24mp A7. This is all possible only if the lenses are able to lay down the super high resolution in their central APS-C zones to get every one of their tightly packed pixels recording useful detail. Zoom lenses are so darned good now that primes tend to be faster and just a bit better in the outer field. On centre it is often a wash.
I therefore have very high hopes that the buyer of an A6000 or A5100 will not only take on an affordable back up body, but be able to make use of the 16-35mm lens to cover not only the very wide end on FF, but the mid range on the APS-C body. If you own a 70-200 FE, then you may also have just found your occasional 300mm too.
Photos to follow in case you don’t believe me!