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| Sony RX100(4) |
This is a question which often appears on user forums.
Many people buy an interchangeable lens camera (DSLR or MILC), mount a 3x kit zoom or convenience/travel/long zoom and leave it there permanently, thereby effectively converting their ILC into a fixed zoom camera (FZC).
I see the opinion often repeated on user forums that an ILC must have better picture quality than any FZC (often referred to as ‘bridge’ or ‘compact’).
The inference would seem to be that the ILC is for enthusiasts and experts and the FZC is for snapshooters who have lower expectations about picture quality and performance . Therefore the FZC is provided with a lower level of capability sufficient to meet those expectations.
My own experience would have led me to agree with this until recently.
There has for many years been a category of advanced compact camera which has been pitched to the enthusiast/expert photographer who doesn’t always want to lug around an ILC kit with several lenses.
Many of these such as the long running Canon G series used the so called ‘1/1.7 inch’ sensor having an actual diagonal measurement of about 9.3mm. These had decent picture quality which never challenged that of the traditional DSLR and was not intended to.
In recent times the capability of advanced compacts has increased considerably due to two technological developments.
The first is the Sony ‘One inch’ (actually 13.2x8.8mm) sensor, now in its third generation. This delivers image quality and performance better than some Micro Four Thirds sensors and even some APS-C sensors.
The second is advancements in aspheric lens design and fabrication allowing the production of collapsing consumer zooms with remarkably high optical quality.
At the same time ILCs have shrunk so that some models such as the Panasonic GM5 with kit lens are smaller than some advanced compacts.
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| RX100(4) |
So which is better ?
Obviously with an ILC you can change lenses. But if you don’t want to change lenses this is moot.
For this exercise, let us stay with the proposition that we will not be changing lenses.
My discussion is mainly about zooms. I am well aware that some photographers like to use prime lenses either on a fixed lens or interchangeable lens camera. So I do make some reference to options using one, or in the case of an ILC, several prime lenses. I used primes for 40 years through the second half of the 20th Century as there were no decent quality zooms available for the consumer market. But current generation zooms are so good I no longer have any inclination to go back to primes.
FZCs go into this comparison with two innate advantages over ILCs.
First: Without the need for a body mount and a lens mount the designers can utilise multiple inner barrels allowing the whole lens construction to telescope back into the body of the camera until the rear element almost touches the sensor.
The result is that the powered off lens can have a very shallow depth.
Second: Most ILCs to date have some form of focal plane shutter. In years to come I think it likely that this will be replaced by a very fast E-shutter or global shutter. The problem with focal plane shutters is they have the potential to cause image blur due to shutter shock. Camera makers have found various workarounds for this including E-Shutter, Electronic First Curtain and more recently a (Panasonic) shutter driven by electromagnets instead of springs. However each of these approaches has its drawbacks.
FZCs use a diaphragm type leaf shutter in the lens. I have not seen any reports of this causing shutter shock.
Let us move on now to consider specific cameras. In their 2016 Roundup of compact enthusiast zoom cameras Digital Photography Review nominated the Sony RX100(4) as best overall and best for video, with the Panasonic ZS/TZ100 best for travel. The previous best camera in this category is the Panasonic LX100 which is still available.
It would appear that my judgement is in line with that of DP Review’s editors because those are the three advanced compacts that I bought and have been using and testing.
I have also been going through the process of deciding whether to settle on a compact or a small ILC for my ‘one lens’ kit. This has involved buying and using and testing several micro four thirds cameras (G7, GX8, GM5) and lenses (Lumix 12-35mm f2.8, 14-42mm and 12-32mm). Our family at some time had a Nikon 1 V2 with 10-100mm lens permanently mounted. I have also examined specifications, reviews and user reports on the Sony A6000/6300 cameras and several compatible E Mount lenses.
The question I wanted to answer is: Is there any ‘one lens’ option based on an ILC from any maker or sensor size which can match the kit size/picture quality balance of the best advanced compacts ?
My conclusion is no. The advantage of the ILC as a camera type is the ability to change lenses.
Remove that from the equation and the advantage goes to the better advanced compacts.
Why ?
Because for any given sensor size and device box volume (length x width x height) the fixed lens type can have either greater zoom range or a wider aperture or both.
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| Photo courtesy of Camerasize.com On the left Panasonic TZ100. On the right Nikon 1 V3 with 10-100mm lens mounted. I had to mock up the Nikon lens to correct size as Camerasize did not have the exact lens in their files. Both cameras have the same sensor size and 10x zoom of approximately equal aperture range. The picture tells the story. |
I illustrate this with some examples.
Nikon 1 V3+10-100mm lens (ILC) vs Panasonic TZ/ZS 100 (FZC).
I have posted this previously but do so again as it tells the whole story in one photo.
Both cameras use the 13.2 x 8.8mm sensor. Both have a 10x zoom of approximately equal aperture range. The TZ100 has, the Nikon 1 V3 does not have a built in EVF.
Look at the size difference. The FZC is actually better specified yet is dramatically smaller.
Each lens has a very similar optical and focussing performance.
Result: The ILC costs more, is much larger and has no advantage over the FZC in any respect.
By the way this comparison also illustrates why I believe the Nikon 1 system as a whole is unlikely to have a future.
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| Photo courtesy of Camerasize.com The RX100(4) on the right has a higher scoring sensor than the Panasonic GM5 on the left. The RX100(4) lens has more zoom range yet still has an aperture two stops wider than the kit lens on the GM5. |
Panasonic GM5 + 12-32mm f3.5-5.6 (ILC) vs Sony RX100(4) (FZC).
The GM5 is amazingly small for an ILC. The body is the same size as that of the RX100(4). It is often sold with the 12-32mm lens shown in the photo. You can see that as soon as a lens is mounted the size advantage goes to the Sony.
But wait, there’s more:
The RX100(4) has a DXO Mark score of 70. The GM5 has a lower score of 66 even though the sensor is larger.
Now look at the lenses. The Sony is f1.8-2.8. The Panasonic is f3.5-5.6. So the Sony has a two stop advantage. Having tested both lenses I can say that the Sony lens can be used with confidence wide open at all focal lengths and that overall it is a better lens than the Panasonic at any focal length or aperture.
Result: An easy win for the RX100(4) which does everything better than the ILC with kit lens, outdoors in bright light or indoors in low light.
I bought a GM5 and tested it with the 12-32mm, 14-42mm and 12-35mm f2.8 zoom lenses. I also tested it with 14mm f2.5 and 20mm f1.7 Lumix primes.
Being a micro Four Thirds camera the GM5 can mount and work with the 12-35mm f2.8 pro standard lens. But although very compact for a high grade constant f2.8 lens the 12-35 is really too big for the GM5 and handles better on a more substantial M43 body.
In fact the only way I could make sense of the GM5 was to use it with the 14mm f2.5 and 20mm f1.7 primes. These two ‘pancake’ style lenses are very small, very good optically and they work well ergonomically on the GM5. But then we are back to changing lenses again and for all that the 14mm has a smaller aperture than the Sony zoom.
Panasonic GX8 +12-35mm f2.8 vs Panasonic LX100
On the numbers the GX8+12-35mm should win this easily.
Indeed, when the two kits are tested side by side on tripod with a highly detailed subject the GX8 clearly reveals more subject detail.
However in general photography and in particular street/documentary/lifestyle work and indoor/low light situations it is difficult to pick which gives the better results.
I tested both side by side for several months and eventually sold the GX8 and all my M43 lenses. I kept the LX100 and my FZ1000 for long lens work.
The LX100 is smaller, lighter and costs half as much as the GX8 kit but makes very good pictures and is more likely to make some kind of picture because I will take the LX100 with me just about anywhere, but that is not so for the GX8 +12-35mm kit.
Sony RX100(4) vs Sony A6000/6300 with ?? lens
The Sony A6000 has been one of the best selling ILCs of recent years. It is very compact for an APS-C ILC and has a very comprehensive specification list. The A6300 is the successor with improvements in almost all specifications but at a much higher price.
I have never owned either the A6000 or the A6300 so my comments are based on reviews and published user reviews.
It seems to me the biggest problem for the Sony (APS-C) E Mount system is the lack of a really convincing standard zoom lens.
Options for a walk around zoom include
* The old 18-55mm f3.5-5.6 which rates badly on reviews.
* The 16-50mm PZ f3.5-5.6 which rates mediocre at best with reports of considerable sample variation.
* The Sony Zeiss 16-70mm constant f4 should be the star E mount standard zoom but it gets at best mediocre reviews with many reports of sample variation.
However let us for this exercise assume we have gotten a really good copy of the Zeiss 16-70mm f4.
An imaginary Mk2 version perhaps, with sharpness right into the corners.
Will this give better results than the Rx100(4) ?
My guess is maybe, sometimes.
At 24 Mpx the A6000/6300 pixel count is 1.2 times that of the RX100 series with 1.1 times the linear pixel count. This will produce a barely detectable difference in photos and then only at high magnification and controlled conditions.
The A6300 does have about a stop more dynamic range which could be useful in some situations.
Overall the A6300 has a DXO Mark score of 85 which is just one EV step better than the RX100(4) score of 70.
To realise the full benefit of this the A6300 would need a lens aperture to match that of the RX100 (4) which ranges from f1.8-2.8. But there is no such zoom lens for the Sony E mount. The closest is the Sony Zeiss 16-70mm constant f4. This lens is 2 stops slower than the RX100(4) at the wide end and one stop slower at the long end.
At the wide end if the RX100(4) could use ISO 100, the A6300 would be using ISO 400.
So the whole equation goes around in circles. The A6300 gains with larger pixels and better IQ at any given ISO setting but loses by having to use a higher ISO setting in many situations.
The only way to get the lens aperture down to f2 or thereabouts is with primes but that gets us back to changing lenses again.
In their review of the RX100(4) the editors of Digital Photography Review make this interesting comment:
“The take-home here being I often find myself getting equally as good results from certain premium compacts as larger sensor DSLRs for still scenes in low light because of the additional exposure I can give these cameras due to their high efficiency sensors, bright built-in lenses, and IS. In other words: don't underestimate the image quality you can get out of these compacts, especially if you take the time to apply some best-practice techniques to shooting and exposure.”
There is further discussion about this issue in the review text.
Summary
Modern advanced compact cameras have become so good they challenge the notion that you need an ILC for good image quality.
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