[APS-C] vs. [FF] on a6500

My question to those more knowledgeable;

Is having an APS-C lens going to be better or worse in terms of image quality performance compared to a Full-Frame lens on a crop sensor camera like the a6500?

There are a few lenses I am looking at (particularly primes) that are offered for both APS-C and FF, but not sure which would be the smarter choice.

mfrymus said:

My question to those more knowledgeable;

Is having an APS-C lens going to be better or worse in terms of image quality performance compared to a Full-Frame lens on a crop sensor camera like the a6500?

There are a few lenses I am looking at (particularly primes) that are offered for both APS-C and FF, but not sure which would be the smarter choice.

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Depend on the specific lenses you are considering. There is not a general rule like "FF is always better than APS-C" or viceversa. Although some people say the opposite, there's not optical disadvantage on using a FF lens on APS-C sensor. Only the price or the size, if that's the case.

Sony has done a big effort in the last years to create a good portfolio of FF lenses and they are very good in general. In the APS-C E-mount range of lenses, some of them are very good some not that much.

Different lens have different characteristics, one really have to test it before concluding.

Expensive FF lens i.e. Zeiss/Sony GM tend to have more special(fancy) glasses to correct distortion/CA, reproduce better colours and more aperture blade for even smoother BOKEH rendering. Also, the image circle is significantly larger than that of an APS-C lens, hence less vignetting when used wide-open on a6500.

Downside is obviously, the cost and size/weight.

I've recently acquired a Sony 12-24mm f4G for my a6500, will be testing it soon during my autumn leave. My experience with Sony 55mm f1.8z on a6500 is, so far so good. There's no "bestbuy" IMO, it all depend on personal flavour and the lens in question. You're the one who's spending after all.

Billy

Nope. I use APS--C and FF lenses on the A6500 and both work equally well.

mfrymus said:

My question to those more knowledgeable;

Is having an APS-C lens going to be better or worse in terms of image quality performance compared to a Full-Frame lens on a crop sensor camera like the a6500?

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Theoretically, then can be better (at least in some ways). It's widely believed that it's easier to make sharper lenses when you're dealing with a smaller image circle (lenses for tiny sensors outresolve lenses for bigger sensors, generally). But that's the general case and doesn't always apply. On the other hand, you're likely to see more consistent performance across an APS-C frame (and less vignetting) with a FF lens.

mfrymus said:

There are a few lenses I am looking at (particularly primes) that are offered for both APS-C and FF, but not sure which would be the smarter choice.

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I base it on more practical considerations - certain focal lengths, particularly WA lenses for APS-C, are only going to be available as crop lenses (like a 16-50 or 18-55) while others may be available, but the FF version is bigger and more expensive (in the case of wide angle lenses, they have to be bigger to cover the image circle). Consider whether you're likely to upgrade to FF - and, importantly, if you were to upgrade to FF, whether the lens is a lens you'd want to use on FF.

Generally, if there are both an APS-C and FF version of a lens, I'd take the APS-C version - it should be smaller, lighter, cheaper, possibly sharper, though not necessarily. Even then, it's not a slam dunk. I currently own both the Sigma 30/1.4 and the Sony 28/2 (full frame). The Sigma is probably sharper, but the Sony is sharp enough to not care (for me). The Sony has (slightly) quicker AF - usefully quicker AF in low light. The Sigma is f/1.4 which allows shallower DOF. The Sony is actually smaller (it is 1 stop slower, but it's still a small lens compared to, say, the Nikkor 28/1.8). I haven't figured out which, if either, I should get rid of because they both have strengths.

- Dennis
--
Gallery at http://kingofthebeasts.smugmug.com

...no real rule. It varies from lens to lens.

val1 said:

...no real rule. It varies from lens to lens.

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yep

The better lens will perform better, regardless if it is a FF or crop lens.

Same experience as others, I have and love two FF lenses on my A6000.

The only downside optically is that if you are shooting a wide angle FF lens on APS-C, you will lose some of the outside diameter.

Now cost and size can be a factor, but if these are not a concern, go for it.

--
Novice photobug. Former NEX-3, F3, and 6 owner. Now a proud A6000 owner.
http://davesnex-3photos.blogspot.com/

I was looking at the Sony 35mm 1.8 and the 50mm 1.8 lenses. But now it looks like Im only looking at the 50mm as im not longer interested in the 35mm.

mfrymus said:

I was looking at the Sony 35mm 1.8 and the 50mm 1.8 lenses. But now it looks like Im only looking at the 50mm as im not longer interested in the 35mm.

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I've seen a lot of people say the SEL50 is as good as the SEL55 when used on an APS-C body. That was not my personal experience. I felt the SEL50 was good, but then I tried the SEL55 and was blown away. Use the SEL50 on an unstabilized body or if you're on a budget. If those aren't constraints, I'd consider the SEL55.

2nd that, the colour reproduction of fe55/1.8z looks better to my eyes. Bokeh are lovely too.

This is not based on my own experience, but I remember reading a comment from someone saying that the extra light from the FF lenses bouncing around inside can potentially decrease image contrast (which explains why adapters, like the MC-11, have felt interiors to absorb light). They also claimed the APS-C sensor would be more demanding than a comparable FF one given a similar number of pixels in a smaller area, and therefore the image may not appear as sharp.

If anyone can confirm the above by taking the same image using the same FF native lens on a a6XXX camera and a FF one (with 24MP sensor), that would help resolve this.

RufusBlack said:

This is not based on my own experience, but I remember reading a comment from someone saying that the extra light from the FF lenses bouncing around inside can potentially decrease image contrast (which explains why adapters, like the MC-11, have felt interiors to absorb light).

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I haven't seen any evidence of this. It would have to be a pretty badly designed camera for that to happen.

RufusBlack said:

They also claimed the APS-C sensor would be more demanding than a comparable FF one given a similar number of pixels in a smaller area, and therefore the image may not appear as sharp.

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An APS-C sensor is more demanding because the image from the lens is enlarged more, but this applies to any lens. It would only be an issue if APS-C lenses were made sharper than FF lenses to compensate, but they aren't.

RufusBlack said:

If anyone can confirm the above by taking the same image using the same FF native lens on a a6XXX camera and a FF one (with 24MP sensor), that would help resolve this.

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I don't have a FF picture to compare, but this picture is from the A6000 with FE 90mm shot wide open. View it full size and let me know if you can see any problems with contrast or sharpness, or if you know of any APS-C lenses that can do better.

RufusBlack said:

This is not based on my own experience, but I remember reading a comment from someone saying that the extra light from the FF lenses bouncing around inside can potentially decrease image contrast (which explains why adapters, like the MC-11, have felt interiors to absorb light). They also claimed the APS-C sensor would be more demanding than a comparable FF one given a similar number of pixels in a smaller area, and therefore the image may not appear as sharp.

If anyone can confirm the above by taking the same image using the same FF native lens on a a6XXX camera and a FF one (with 24MP sensor), that would help resolve this.

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I only have FE lenses for my a6000 and a7, and I share them about quite often with good results. Both of these cameras are 24MPix, and I can only detect a very minor advantage for the full-frame; it's in the region of 5% when checked on a standard resolution chart.


35mm f/2.8 is a neat package.


70-200mm f/4 is a natural fit for the a6000.

Pixel Pooper said:

Pixel Pooper:

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Pixel Pooper, nice capture.

Yep, the FE 90mm f/2.8 is amazing and works well on the APS-C. I use my FE 90mm f/2.8 on my A6300 often for portraits and love the results.

--
A6000, A6300, A99, A900, A55, A700, R1, w/Sony + Zeiss + Sony G Glass

it should be better. it is twice the price.

I have the SEL50F18, and the A6000. I also just picked up the SEL55F18Z. To my eye, they are very close, with the 55 being ever so slightly better: A little higher in contrast, perhaps slightly sharper. Maybe my SEL50F18 is a good copy. I have not checked the corners, but the centers seem very close.

mfrymus said:

Is having an APS-C lens going to be better or worse in terms of image quality performance compared to a Full-Frame lens on a crop sensor camera like the a6500?

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You can just as easily get rubbish FF lenses, so just because it's FF doesn't automatically make shots better than the equivalent APS-C lens.

Personally I started buying FF lenses when the Zeiss Batis 85mm came out. I just loved it's sharpness and colour and used it with my A6000 for years, along with the 18mm and 25mm Batis later. Never a problem in use and always great shots, and it lined me up to upgrade to the A7Riii recently. The same lenses produce the exact same quality shots on my new FF toy, but this time with extra resolution.

But before the Batis, I bought the Sony 35mm and 50mm APS-C primes. Both excellent lenses in my view only pipped out slightly by the more expensive Sony-Zeiss versions.

As someone else pointed out, you will get some extra benefits like less vignetting and the like with FF lenses on APS-C bodies, but beyond that it's just a general case of investing in decent glass (regardless of whether it's FF or not) to get the kind of quality image you're after.