Compact Camera Zoom Comparison — RX100, EX-ZR100, SX620 HS and SX700 HS

Compact digital cameras can look surprisingly similar when they are turned off, but a compact camera zoom comparison shows just how different their lens designs really are.

Turn them on and extend their zoom lenses, and those differences become much easier to see.

For this comparison, we placed four compact cameras side by side:

• Sony Cyber-shot DSC-RX100

• Casio EXILIM EX-ZR100

• Canon PowerShot SX620 HS

• Canon PowerShot SX700 HS

All four are compact digital cameras, but their lenses were designed with very different priorities.

The Sony RX100 offers only 3.6× optical zoom, while the Canon SX700 HS reaches 30×.

Does that mean the SX700 HS simply has a “better” lens?

Not necessarily.

Zoom range, lens brightness, sensor size, camera dimensions, and intended use all influence how a compact-camera lens is designed.

This guide uses these four real cameras to explain those differences.

Compact Camera Zoom Comparison: Four Cameras, Four Different Lenses

At first glance, the physical difference between these cameras is striking.

The lenses extend by different amounts, and the cameras themselves vary considerably in thickness and overall design.

But the amount a lens physically extends should not be treated as a direct measurement of image quality or zoom performance.

Internal lens construction also differs between cameras.

What the photograph does show clearly is that compact-camera manufacturers used very different approaches to fitting zoom lenses into relatively small bodies.

Here are the basic differences between the four cameras.

Camera	Optical Zoom	35mm-Equivalent Range	Maximum Aperture
Sony Cyber-shot DSC-RX100	3.6×	28–100mm	F1.8–4.9
Casio EXILIM EX-ZR100	12.5×	24–300mm	F3.0–5.9
Canon PowerShot SX620 HS	25×	25–625mm	F3.2–6.6
Canon PowerShot SX700 HS	30×	25–750mm	F3.2–6.9

The progression looks straightforward:

3.6× → 12.5× → 25× → 30×

But zoom magnification alone tells only part of the story.

What Does Optical Zoom Actually Mean?

Optical zoom changes the field of view by physically adjusting the camera's lens elements.

A camera with a longer telephoto focal length can make distant subjects appear much larger in the frame without relying entirely on digital cropping.

For example, the Sony RX100 reaches approximately 100mm equivalent at its telephoto end.

The Canon SX700 HS reaches approximately 750mm equivalent.

That is an enormous difference in reach.

However, a longer zoom range normally requires compromises elsewhere.

A compact camera must balance several things:

• Camera size

• Lens size

• Maximum aperture

• Sensor size

• Image stabilization

• Optical complexity

• Cost

• Intended use

This is why comparing cameras only by their “× zoom” number can be misleading.

Sony Cyber-shot DSC-RX100 — Image Quality Before Extreme Zoom

The original Sony Cyber-shot DSC-RX100 represents a very different design philosophy from the two Canon superzoom cameras.

Its lens covers approximately 28–100mm equivalent, giving it a 3.6× optical zoom.

That may look modest next to 25× or 30×.

But the RX100 was not designed primarily to photograph extremely distant subjects.

Its major advantage is the combination of a comparatively large 1-inch sensor and a bright lens that opens to F1.8 at the wide end.

That allows the camera to gather more light than many small-sensor superzoom compacts.

The RX100 therefore puts more emphasis on:

• Image quality

• Low-light capability

• Background separation

• Lens brightness

• Compact size

rather than extreme telephoto reach.

This is an important lesson when comparing compact-camera lenses:

less zoom does not automatically mean a worse lens.

The RX100 simply prioritizes something different.

Casio EXILIM EX-ZR100 — A Middle Ground

The Casio EXILIM EX-ZR100 sits between the RX100 and the Canon superzoom cameras.

Its 12.5× optical zoom covers approximately 24–300mm equivalent.

That range is already very versatile.

At 24mm equivalent, it can handle relatively wide scenes such as landscapes, streets, buildings, and group photographs.

At 300mm equivalent, it can reach much farther than the RX100.

This makes the EX-ZR100 an interesting middle ground.

It offers considerably more telephoto reach than a premium short-zoom compact without extending into the extreme 600–750mm territory of the Canon SX models.

The EX-ZR100 is also notable for its high-speed shooting features, which were an important part of Casio's EXILIM technology during this period.

Its lens therefore works as part of a broader concept:

a relatively compact camera with useful zoom reach and fast shooting capabilities.

Canon PowerShot SX620 HS — 25× Zoom in a Small Body

The Canon PowerShot SX620 HS takes a much more aggressive approach to zoom range.

Its lens covers approximately 25–625mm equivalent, providing 25× optical zoom.

That means the camera can move from a useful wide-angle view to a very long telephoto view without changing lenses.

What makes the SX620 HS particularly interesting is its size.

Despite reaching 625mm equivalent, it remains a relatively slim pocket-sized compact camera.

This was one of the major appeals of this generation of travel-zoom cameras.

A traveler could photograph:

• Streets

• Buildings

• Landscapes

• Friends and family

• Architectural details

• Distant objects

with one small camera.

The trade-off becomes visible in the aperture range.

The lens begins at approximately F3.2 and reaches around F6.6 at the telephoto end.

Compared with the RX100's F1.8 wide-angle aperture, the SX620 HS lens is considerably less bright.

That does not make it inferior.

It simply shows that Canon prioritized zoom reach and portability.

Canon PowerShot SX700 HS — Maximum Reach of the Four

The Canon PowerShot SX700 HS has the longest optical zoom range of these four cameras.

Its 30× optical zoom covers approximately 25–750mm equivalent.

That is a remarkable focal range for a compact digital camera.

At the wide end, the camera can handle normal travel and landscape photography.

At the telephoto end, 750mm equivalent allows much more distant subjects to fill the frame.

This makes the SX700 HS particularly useful for subjects such as:

• Distant buildings

• Wildlife

• Birds

• Sporting events

• Stage performances

• Travel details

• Objects that cannot easily be approached

The camera is larger than the SX620 HS, and that difference makes sense when considering its longer zoom system.

The SX700 HS represents the most telephoto-focused design of the four cameras in this comparison.

Why Does the SX700 HS Lens Extend So Much?

A zoom lens contains multiple optical elements that move relative to one another.

To cover a focal-length range from approximately 25mm to 750mm equivalent, the lens system must dramatically change its optical configuration between the wide and telephoto positions.

Some of this movement happens inside the lens barrel, while some is visible as the lens extends outward.

That is why high-zoom compact cameras often look almost surprisingly different when switched on.

A camera that looks relatively thin while powered off can develop a substantial lens barrel once zoomed toward the telephoto end.

The two photographs in this article make that physical transformation easy to see.

However, the visible length of the barrel alone does not tell us which lens is optically better.

Lens design is much more complicated than simply measuring how far the barrel extends.

Why Doesn't the RX100 Have a 25× Zoom?

This is probably the most important question in this comparison.

If Canon could build a 25× compact camera, why did Sony give the RX100 only 3.6×?

Because the cameras were built around different priorities.

The RX100 uses a much larger sensor than typical travel-zoom compact cameras.

A larger sensor requires a larger image circle from the lens.

Building a very bright lens, covering a large sensor, providing extreme zoom, and still keeping the camera genuinely pocketable becomes increasingly difficult.

Sony therefore made a deliberate compromise.

Instead of offering 25× or 30× zoom, the RX100 combines:

**a relatively short zoom range

• a bright lens

• a larger sensor

• a small camera body**

Canon's SX series takes another path:

**a smaller sensor

• a much longer optical zoom

• a relatively compact body**

Neither approach is universally better.

They solve different problems.

Zoom Range vs. Lens Brightness

This comparison also helps explain the importance of the F-number.

A lower F-number indicates a wider aperture, which can allow more light to reach the sensor.

The RX100 begins at F1.8.

The EX-ZR100 begins at F3.0.

The SX620 HS and SX700 HS begin at around F3.2.

As these zoom lenses move toward telephoto, their maximum apertures become smaller.

This matters especially in lower light.

Long telephoto photography already magnifies camera movement, and a relatively small aperture may require the camera to compensate with:

• slower shutter speeds

• higher ISO sensitivity

• image stabilization

For bright outdoor photography, this may not be a major problem.

For indoor or evening photography, however, the brighter RX100 lens can offer advantages even though its zoom range is much shorter.

Is More Optical Zoom Always Better?

No.

A higher optical zoom ratio gives you more framing flexibility, but it does not automatically produce better photographs.

Consider two very different situations.

If you want to photograph a bird sitting far away, the SX700 HS's 750mm-equivalent telephoto reach is enormously useful.

The RX100 simply cannot frame the same distant subject as tightly using optical zoom alone.

But if you are photographing people indoors in relatively low light, the RX100's larger sensor and brighter lens may be far more valuable than 30× zoom.

The question is therefore not:

Which camera has the biggest zoom?

A better question is:

What type of photography was this lens designed for?

Digital Zoom Is Different from Optical Zoom

It is also important to separate optical zoom from digital zoom.

Optical zoom changes the image using the physical lens.

Digital zoom enlarges part of the captured image electronically.

Some cameras also use more advanced forms of digital or multi-frame processing to extend apparent zoom reach.

These features can sometimes be useful, but they should not be confused with the camera's true optical focal-length range.

For this article, the primary comparison is based on optical zoom.

What About the Physical Size of the Lens?

The photographs show another interesting point.

Compact cameras were remarkable pieces of mechanical engineering.

A large amount of optical hardware had to fit inside bodies small enough to carry in a pocket or small bag.

Manufacturers used collapsible multi-stage lens barrels so that the camera could remain relatively thin when powered off.

Once switched on, the barrel extends.

Zooming farther toward telephoto may extend or internally rearrange the lens even further.

This means the camera effectively transforms from a small rectangular object into a working optical system.

Looking at several cameras together makes that engineering much easier to appreciate.

Which Zoom Range Is Best for Different Uses?

There is no single ideal zoom range.

Sony RX100 — Best When Image Quality Matters More Than Reach

The RX100 makes the most sense when you value:

• Better image quality

• A brighter lens

• Indoor photography

• Everyday photography

• Portraits

• Compact size

Its 100mm-equivalent telephoto end is useful, but long-distance photography is not its main strength.

Casio EX-ZR100 — A Versatile Middle Ground

The EX-ZR100 works well when you want:

• A wider 24mm starting point

• Useful 300mm telephoto reach

• Travel flexibility

• High-speed shooting features

• More zoom without moving into an extreme superzoom design

Its 12.5× range covers a lot of everyday situations.

Canon SX620 HS — Pocketable Long Zoom

The SX620 HS is particularly interesting for:

• Travel

• Sightseeing

• Distant buildings

• Outdoor photography

• Users who want strong zoom in a small camera

Its 625mm-equivalent telephoto reach is impressive for such a compact body.

Canon SX700 HS — When Telephoto Reach Is the Priority

The SX700 HS makes the most sense when you want:

• Maximum reach among these four cameras

• Wildlife and birds

• Events

• Distant architectural details

• Outdoor subjects that cannot easily be approached

Its 750mm-equivalent telephoto end provides a capability that short-zoom compacts simply cannot reproduce optically.

Four Cameras Show Four Different Design Philosophies

Placed together, these four cameras form an interesting progression.

Sony RX100→ image quality and lens brightness

Casio EX-ZR100→ balance between portability and zoom

Canon SX620 HS→ very long zoom in a small body

Canon SX700 HS→ even greater telephoto reach

This is why compact digital cameras are more interesting than their external appearance might suggest.

Two cameras can both fit into the broad category of “compact digital camera” while being designed for completely different types of photography.

What These Real Cameras Show

The photographs in this article are useful because they show something specification tables cannot communicate particularly well.

They show the physical reality of compact-camera lens design.

The RX100's relatively restrained lens, the EX-ZR100's middle-ground design, and the much longer Canon SX zoom assemblies represent different engineering choices.

None of the four is simply the “correct” solution.

Each one reflects a different answer to the same question:

What should a compact digital camera be able to do?

A Future Real-World Zoom Comparison

This article focuses on the lenses themselves and the differences in their optical designs.

A useful next step would be to photograph the same distant subject from the same location with all four cameras.

That would make it possible to compare directly what approximately:

• 100mm

• 300mm

• 625mm

• 750mm

equivalent focal lengths actually look like in real-world use.

That comparison would show not just how far the lenses physically extend, but how dramatically focal length changes what appears in the final photograph.

Final Thoughts

The Sony RX100, Casio EX-ZR100, Canon SX620 HS, and Canon SX700 HS demonstrate just how different compact-camera lenses can be.

The RX100 sacrifices extreme zoom to support a larger sensor and brighter lens.

The EX-ZR100 provides a versatile 12.5× range between wide-angle and telephoto photography.

The SX620 HS pushes optical zoom much farther while remaining remarkably compact.

And the SX700 HS extends that idea to 30× and a 750mm-equivalent telephoto range.

Looking only at the zoom number would suggest a simple ranking from 3.6× to 30×.

In reality, the story is much more interesting.

A lens is a collection of compromises.

Zoom reach, brightness, camera size, sensor size, portability, and intended use all influence its design.

Understanding those differences makes it much easier to choose a compact camera for the kind of photography you actually want to do.