A potelyt.com – Photography & Imaging Resources
ad

When you use links on apotelyt.com to buy products,
the site may earn a commission.

PW

Canon SX730 vs Sony HX99

The Canon PowerShot SX730 HS and the Sony Cyber-shot DSC-HX99 are two digital cameras that were revealed to the public, respectively, in April 2017 and August 2018. Both the SX730 and the HX99 are fixed lens compact cameras that are equipped with a 1/2.3-inch sensor. The Canon has a resolution of 20.2 megapixels, whereas the Sony provides 18 MP.

Below is an overview of the main specs of the two cameras as a starting point for the comparison.

Headline Specifications
Canon SX730
versus
Sony HX99
Canon SX730   Sony HX99
Fixed lens compact camera Fixed lens compact camera
24-960mm f/3.3-6.9 24-720mm f/3.5-6.4
20.2 MP – 1/2.3" sensor 18 MP – 1/2.3" sensor
1080/60p Video 4K/30p Video
ISO 80-3,200 ISO 80-3,200 (80 - 6,400)
No viewfinder, LCD framing Electronic viewfinder (638k dots)
3.0" LCD – 922k dots 3.0" LCD – 922k dots
Tilting screen (no touchscreen) Tilting touchscreen
5.9 shutter flaps per second 10 shutter flaps per second
250 shots per battery charge370 shots per battery charge
110 x 64 x 40 mm, 300 g 102 x 58 x 36 mm, 242 g
logo
Check SX730 offers at
ebay.com
logo
Check HX99 offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Canon PowerShot SX730 HS and the Sony Cyber-shot DSC-HX99? Which one should you buy? Read on to find out how these two cameras compare with respect to their body size, their imaging sensors, their shooting features, their input-output connections, and their reception by expert reviewers.

ad

Body comparison

The side-by-side display below illustrates the physical size and weight of the Canon SX730 and the Sony HX99. The two cameras are presented according to their relative size. Three consecutive views from the front, the top, and the rear side are shown. All width, height and depth measures are rounded to the nearest millimeter.

The SX730 can be obtained in two different colors (black, silver), while the HX99 is only available in black.

Size Canon SX730 vs Sony HX99
Compare SX730 versus HX99 top
Comparison SX730 or HX99 rear

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Sony HX99 is notably smaller (16 percent) than the Canon SX730. Moreover, the HX99 is markedly lighter (19 percent) than the SX730. In this context, it is worth noting that neither the SX730 nor the HX99 are weather-sealed.

Concerning battery life, the SX730 gets 250 shots out of its Canon NB-13L battery, while the HX99 can take 370 images on a single charge of its Sony NP-BX1 power pack. The battery packs of both cameras can be charged via USB, which can be very convenient when travelling.

The following table provides a synthesis of the main physical specifications of the two cameras and other similar ones. If you want to switch the focus of the display and review another camera pair, you can move across to the CAM-parator tool and choose from the broad selection of possible camera comparisons there.

scroll hint
Body Specifications
# image Camera
Model
Camera
Width
Camera
Height
Camera
Depth
Camera
Weight
Battery
Life
Weather
Sealing
Camera
Launch
Launch
Price (USD)
Street
Price
1.
 
Canon SX730 110 mm 64 mm 40 mm 300 g 250 n Apr 2017 399ebay.com
2.
 
Sony HX99 102 mm 58 mm 36 mm 242 g 370 n Aug 2018 449ebay.com
3.
 
Canon SX740 110 mm 64 mm 40 mm 299 g 265 n Jul 2018 399 amazon.com
4.
 
Canon SX430 104 mm 69 mm 85 mm 323 g 195 n Jan 2017 299ebay.com
5.
 
Canon G7 X Mark II 106 mm 61 mm 42 mm 319 g 265 n Feb 2016 699ebay.com
6.
 
Canon SX420 104 mm 69 mm 85 mm 325 g 195 n Jan 2016 299ebay.com
7.
 
Canon SX540 120 mm 82 mm 92 mm 442 g 205 n Jan 2016 399ebay.com
8.
 
Canon SX720 110 mm 64 mm 36 mm 270 g 250 n Feb 2016 379ebay.com
9.
 
Canon SX710 113 mm 66 mm 35 mm 269 g 230 n Jan 2015 349ebay.com
10.
 
Panasonic TS7 117 mm 76 mm 37 mm 319 g 300 Y May 2018 449ebay.com
11.
 
Panasonic ZS70 112 mm 67 mm 41 mm 322 g 380 n Apr 2017 449ebay.com
12.
 
Sony HX95 102 mm 58 mm 36 mm 242 g 370 n Aug 2018 429ebay.com
13.
 
Sony WX800 102 mm 58 mm 36 mm 233 g 370 n Oct 2018 399ebay.com
14.
 
Sony HX90V 102 mm 58 mm 36 mm 245 g 360 n Apr 2015 429ebay.com
15.
 
Sony HX400V 130 mm 93 mm 103 mm 660 g 300 n Feb 2014 499ebay.com
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
padding

Any camera decision will naturally be influenced heavily by the price. The listed launch prices provide an indication of the market segment that the manufacturer of the cameras have been targeting. The SX730 was launched at a somewhat lower price (by 11 percent) than the HX99, which makes it more attractive for photographers on a tight budget. Usually, retail prices stay at first close to the launch price, but after several months, discounts become available. Later in the product cycle and, in particular, when the replacement model is about to appear, further discounting and stock clearance sales often push the camera price considerably down.

Sensor comparison

The size of the imaging sensor is a crucial determinant of image quality. All other things equal, a large sensor will have larger individual pixel-units that offer better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixels in a sensor of the same technological generation. Further, a large sensor camera will give the photographer additional creative options when using shallow depth-of-field to isolate a subject from its background. On the downside, larger sensors are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Both cameras under consideration feature a 1/2.3-inch sensor and have a format factor (sometimes also referred to as "crop factor") of 5.6. Within the spectrum of camera sensors, this places the review cameras among the smaller-sensor digicams that favor affordability and compact design. Both cameras feature a native aspect ratio (sensor width to sensor height) of 4:3.

Canon SX730 and Sony HX99 sensor measures

While the two cameras under review share the same sensor size, the SX730 offers a higher resolution of 20.2 megapixels, compared with 18 MP of the HX99. This megapixels advantage translates into a 6 percent gain in linear resolution. On the other hand, these sensor specs imply that the SX730 has a higher pixel density and a smaller size of the individual pixel (with a pixel pitch of 1.18μm versus 1.25μm for the HX99). Moreover, it should be noted that the HX99 is a somewhat more recent model (by 1 year and 4 months) than the SX730, and its sensor might have benefitted from technological advances during this time that further enhance the light gathering capacity of individual pixels. Coming back to sensor resolution, it should be mentioned that neither of the two cameras has an anti-alias filter installed, so they are able to capture all the detail the sensor resolves.

The resolution advantage of the Canon SX730 implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the SX730 for good quality output (200 dots per inch) amounts to 25.9 x 19.4 inches or 65.8 x 49.4 cm, for very good quality (250 dpi) 20.7 x 15.6 inches or 52.7 x 39.5 cm, and for excellent quality (300 dpi) 17.3 x 13 inches or 43.9 x 32.9 cm. The corresponding values for the Sony HX99 are 24.5 x 18.4 inches or 62.2 x 46.6 cm for good quality, 19.6 x 14.7 inches or 49.7 x 37.3 cm for very good quality, and 16.3 x 12.2 inches or 41.5 x 31.1 cm for excellent quality prints.

The Canon PowerShot SX730 HS has a native sensitivity range from ISO 80 to ISO 3200. The corresponding ISO settings for the Sony Cyber-shot DSC-HX99 are ISO 80 to ISO 3200, with the possibility to increase the ISO range to 80-6400.

In terms of underlying technology, the SX730 is build around a BSI-CMOS sensor, while the HX99 uses a CMOS imager. Both cameras use a Bayer filter for capturing RGB colors on a square grid of photosensors. This arrangement is found in most digital cameras.

SX730 versus HX99 MP

For many cameras, data on sensor performance has been reported by DXO Mark. This service determines an overall sensor rating, as well as sub-scores for low-light sensitivity ("DXO Sports"), dynamic range ("DXO Landscape"), and color depth ("DXO Portrait"). The adjacent table reports on the physical sensor characteristics and the outcomes of the DXO sensor quality tests for a sample of comparator-cameras.

scroll hint
Sensor Characteristics
# image Camera
Model
Sensor
Class
Resolution
(MP)
Horiz.
Pixels
Vert.
Pixels
Video
Format
DXO
Portrait
DXO
Landscape
DXO
Sports
DXO
Overall
1.
 
Canon SX730 1/2.3 20.2 5184 38881080/60p20.511.992450
2.
 
Sony HX99 1/2.3 18.0 4896 36724K/30p20.612.1105851
3.
 
Canon SX740 1/2.3 20.2 5184 38884K/30p20.612.1105051
4.
 
Canon SX430 1/2.3 19.9 5152 3864720/25p20.511.990049
5.
 
Canon G7 X Mark II 1-inch 20.0 5472 36481080/60p21.811.926062
6.
 
Canon SX420 1/2.3 19.9 5152 3864720/25p20.311.780648
7.
 
Canon SX540 1/2.3 20.2 5184 38881080/60p20.311.780648
8.
 
Canon SX720 1/2.3 20.2 5184 38881080/60p20.311.881748
9.
 
Canon SX710 1/2.3 20.2 5184 38881080/60p20.211.671247
10.
 
Panasonic TS7 1/2.3 20.2 5184 38884K/30p20.612.1102851
11.
 
Panasonic ZS70 1/2.3 20.2 5184 38884K/30p19.110.610636
12.
 
Sony HX95 1/2.3 18.0 4896 36724K/30p20.612.1105751
13.
 
Sony WX800 1/2.3 18.0 4896 36724K/30p20.612.2107051
14.
 
Sony HX90V 1/2.3 18.0 4896 36721080/60p20.211.673847
15.
 
Sony HX400V 1/2.3 20.2 5184 38881080/60p20.111.462945
Note: DXO values in italics represent estimates based on sensor size and age.
padding

Many modern cameras are not only capable of taking still images, but can also record movies. Both cameras under consideration are equipped with sensors that have a sufficiently high read-out speed for moving images, but the HX99 provides a better video resolution than the SX730. It can shoot movie footage at 4K/30p, while the Canon is limited to 1080/60p.

ad

Feature comparison

Apart from body and sensor, cameras can and do differ across a variety of features. For example, the HX99 has an electronic viewfinder (638k dots), which can be very helpful when shooting in bright sunlight. In contrast, the SX730 relies on live view and the rear LCD for framing. The following table reports on some other key feature differences and similarities of the Canon SX730, the Sony HX99, and comparable cameras.

scroll hint
Core Features
# image Camera
Model
Viewfinder
(Type or
000 dots)
Control
Panel
(yes/no)
LCD
Specifications
(inch/000 dots)
LCD
Attach-
ment
Touch
Screen
(yes/no)
Max
Shutter
Speed *
Max
Shutter
Flaps *
Built-in
Flash
(yes/no)
Built-in
Image
Stab
1.
 
Canon SX730none n3.0 / 922 tilting n 1/3200s 5.9/s Y Y
2.
 
Sony HX99638 n3.0 / 922 tilting Y 1/2000s 10.0/s Y Y
3.
 
Canon SX740none n3.0 / 922 tilting n 1/3200s 10.0/s Y Y
4.
 
Canon SX430none n3.0 / 230 fixed n 1/4000s 0.5/s Y Y
5.
 
Canon G7 X Mark IInone n3.0 / 1040 tilting Y 1/2000s 8.0/s Y Y
6.
 
Canon SX420none n3.0 / 230 fixed n 1/4000s 0.5/s Y Y
7.
 
Canon SX540none n3.0 / 461 fixed n 1/2000s 5.9/s Y Y
8.
 
Canon SX720none n3.0 / 922 fixed n 1/3200s 5.9/s Y Y
9.
 
Canon SX710none n3.0 / 922 fixed n 1/3200s 6.0/s Y Y
10.
 
Panasonic TS71170 n3.0 / 1040 fixed n 1/1300s 10.0/s Y Y
11.
 
Panasonic ZS701166 n3.0 / 1040 tilting Y 1/2000s 10.0/s Y Y
12.
 
Sony HX95638 n3.0 / 922 tilting n 1/2000s 10.0/s Y Y
13.
 
Sony WX800none n3.0 / 922 tilting Y 1/2000s 10.0/s Y Y
14.
 
Sony HX90V638 n3.0 / 921 tilting n 1/2000s 10.0/s Y Y
15.
 
Sony HX400V210 n3.0 / 921 tilting n 1/4000s 10.0/s Y Y
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.
padding

One differentiating feature between the two cameras concerns the touch sensitivity of the rear screen. The HX99 has a touchscreen, while the SX730 has a conventional panel. Touch control can be particularly helpful, for example, for setting the focus point.

Both cameras have an articulated rear screen that can be turned to be front-facing. This feature will be particularly appreciated by vloggers and photographers who are interested in taking selfies.

Both the SX730 and the HX99 have zoom lenses built in. The SX730 has a 24-960mm f/3.3-6.9 optic and the HX99 offers a 24-720mm f/3.5-6.4 (focal lengths in full frame equivalent terms). Hence, the Canon and Sony provide the same view at the wide-angle end, but the Sony has less tele-photo reach at the long end. The SX730 offers the faster maximum aperture.

The SX730 writes its imaging data to SDXC cards, while the HX99 uses SDXC or Memory Stick PRO Duo cards. The HX99 supports UHS-I cards (Ultra High Speed data transfer of up to 104 MB/s), while the SX730 cannot take advantage of Ultra High Speed SD cards.

ad

Connectivity comparison

For some imaging applications, the extent to which a camera can communicate with its environment can be an important aspect in the camera decision process. The table below provides an overview of the connectivity of the Canon PowerShot SX730 HS and Sony Cyber-shot DSC-HX99 and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.

scroll hint
Input-Output Connections
# image Camera
Model
Hotshoe
Port
Internal
Mic / Speaker
Microphone
Port
Headphone
Port
HDMI
Port
USB
Port
WiFi
Support
NFC
Support
Bluetooth
Support
1.
 
Canon SX730-stereo / mono--micro2.0YYY
2.
 
Sony HX99-stereo / mono--micro2.0YYY
3.
 
Canon SX740-stereo / mono--micro2.0Y-Y
4.
 
Canon SX430-mono / mono---2.0YY-
5.
 
Canon G7 X Mark II-stereo / mono--micro2.0YY-
6.
 
Canon SX420-mono / mono---2.0YY-
7.
 
Canon SX540-stereo / mono--mini2.0YY-
8.
 
Canon SX720-stereo / mono--micro2.0YY-
9.
 
Canon SX710-stereo / mono--micro2.0YY-
10.
 
Panasonic TS7-stereo / mono--micro2.0Y--
11.
 
Panasonic ZS70-stereo / mono--micro2.0Y--
12.
 
Sony HX95-stereo / mono--micro2.0YYY
13.
 
Sony WX800-stereo / mono--micro2.0YY-
14.
 
Sony HX90V-stereo / mono--micro2.0YY-
15.
 
Sony HX400VYstereo / mono--micro2.0YY-
padding

Both the SX730 and the HX99 have been discontinued, but can regularly be found used on ebay. The SX730 was replaced by the Canon SX730 HS, while the HX99 does not have a direct successor. Further information on the features and operation of the SX730 and HX99 can be found, respectively, in the Canon SX730 Manual (free pdf) or the online Sony HX99 Manual.

ad

Review summary

So what conclusions can be drawn? Is there a clear favorite between the Canon SX730 and the Sony HX99? Which camera is better? A synthesis of the relative strong points of each of the models is listed below.

ilogo

Arguments in favor of the Canon PowerShot SX730 HS:

  • More detail: Offers more megapixels (20.2 vs 18MP) with a 6% higher linear resolution.
  • Faster shutter: Has higher mechanical shutter speed (1/3200s vs 1/2000s) to freeze action.
  • Better light gathering: Has a lens with a wider maximum aperture (f/3.3 vs f/3.5).
  • More tele-reach: Has a longer tele-lens for perspective compression and subject magnification.
  • More affordable: Was introduced into a lower priced segment (11 percent cheaper at launch).
  • More heavily discounted: Has been on the market for longer (launched in April 2017).

ilogo

Reasons to prefer the Sony Cyber-shot DSC-HX99:

  • Better video: Provides higher definition movie capture (4K/30p vs 1080/60p).
  • Easier framing: Has an electronic viewfinder for image composition and settings control.
  • Fewer buttons to press: Has a touchscreen to facilitate handling and shooting adjustments.
  • Faster burst: Shoots at higher frequency (10 vs 5.9 flaps/sec) to capture the decisive moment.
  • More compact: Is smaller (102x58mm vs 110x64mm) and will fit more readily into a bag.
  • Less heavy: Has a lower weight (by 58g or 19 percent) and is thus easier to take along.
  • Longer lasting: Gets more shots (370 versus 250) out of a single battery charge.
  • Faster buffer clearing: Has an SD card interface that supports the UHS-I standard.
  • More modern: Was introduced somewhat (1 year and 4 months) more recently.

If the number of relative strengths (bullet points above) is taken as a guide, the HX99 emerges as the winner of the match-up (9 : 6 points). However, the pertinence of the various camera strengths will differ across photographers, so that you might want to weigh individual camera traits according to their importance for your own imaging needs before making a camera decision. A professional sports photographer will view the differences between cameras in a way that diverges from the perspective of a street photog, and a person interested in family portraits has distinct needs from a landscape shooter. Hence, the decision which camera is best and worth buying is often a very personal one.

SX730 06:09 HX99

How about other alternatives? Do the specifications of the Canon SX730 and the Sony HX99 place the cameras among the top in their class? Find out in the latest Best Superzoom Camera listing whether the two cameras rank among the cream of the crop.

In any case, while the comparison of the spec-sheets of cameras can offer a general idea of their imaging potential, it remains partial and cannot reveal, for example, the shooting experience and imaging performance when actually working with the SX730 or the HX99. User reviews, such as those found at amazon, can sometimes inform about these issues, but such feedback is often incomplete, inconsistent, and biased.

Expert reviews

This is where reviews by experts come in. The following table reports the overall ratings of the cameras as published by some of the major camera review sites (amateurphotographer [AP], cameralabs [CL], digitalcameraworld [DCW], dpreview [DPR], ephotozine [EPZ], photographyblog [PB]). As can be seen, the professional reviewers agree in many cases on the quality of different cameras, but sometimes their assessments diverge, reinforcing the earlier point that a camera decision is often a very personal choice.

scroll hint
Expert Camera Reviews
# image  Camera 
 Model 
 AP 
 score 
 CL 
 score 
 DCW 
 score 
 DPR 
 score 
 EPZ 
 score 
 PB 
 score 
Camera
Launch
Launch
Price (USD)
Street
Price
1.
 
Canon SX730..+....4/54/5 Apr 2017 399ebay.com
2.
 
Sony HX99........4/54.5/5 Aug 2018 449ebay.com
3.
 
Canon SX740..+3.5/5..4/54/5 Jul 2018 399 amazon.com
4.
 
Canon SX430........3.5/53.5/5 Jan 2017 299ebay.com
5.
 
Canon G7 X Mark II4.5/5+ +..81/1004.5/54.5/5 Feb 2016 699ebay.com
6.
 
Canon SX420..........3/5 Jan 2016 299ebay.com
7.
 
Canon SX540............ Jan 2016 399ebay.com
8.
 
Canon SX720..+....4/54.5/5 Feb 2016 379ebay.com
9.
 
Canon SX710..+....4/53.5/5 Jan 2015 349ebay.com
10.
 
Panasonic TS7..+......3.5/5 May 2018 449ebay.com
11.
 
Panasonic ZS70..+ +....4/54/5 Apr 2017 449ebay.com
12.
 
Sony HX95............ Aug 2018 429ebay.com
13.
 
Sony WX800............ Oct 2018 399ebay.com
14.
 
Sony HX90V4/5+ +....4/54.5/5 Apr 2015 429ebay.com
15.
 
Sony HX400V4/5+ +....4/54/5 Feb 2014 499ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.
padding

The above review scores should be interpreted with care, though. The ratings are only valid when referring to cameras in the same category and of the same age. Hence, a score should always be seen in the context of the camera's market launch date and its price, and rating-comparisons among cameras that span long time periods or concern very differently equipped models make little sense. Also, please note that some of the review sites have changed their methodology and reporting over time.

logo
Check SX730 offers at
ebay.com
logo
Check HX99 offers at
ebay.com

Other camera comparisons

Did this review help to inform your camera decision process? If you would like to see a different side-by-side camera review, just make a corresponding selection in the search boxes below. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.

~
    loader
    ad

    Specifications: Canon SX730 vs Sony HX99

    Below is a side-by-side comparison of the specs of the two cameras to facilitate a quick review of their differences and common features.

    Camera Specifications
    Camera Model Canon SX730 Sony HX99
    Camera Type Fixed lens compact camera Fixed lens compact camera
    Camera Lens 24-960mm f/3.3-6.9 24-720mm f/3.5-6.4
    Launch Date April 2017 August 2018
    Launch Price USD 399 USD 449
    Sensor Specs Canon SX730 Sony HX99
    Sensor Technology BSI-CMOS CMOS
    Sensor Format 1/2.3" Sensor 1/2.3" Sensor
    Sensor Size 6.17 x 4.55 mm 6.17 x 4.55 mm
    Sensor Area 28.0735 mm2 28.0735 mm2
    Sensor Diagonal 7.7 mm 7.7 mm
    Crop Factor 5.6x 5.6x
    Sensor Resolution 20.2 Megapixels 18 Megapixels
    Image Resolution 5184 x 3888 pixels 4896 x 3672 pixels
    Pixel Pitch 1.18 μm 1.25 μm
    Pixel Density 71.80 MP/cm2 64.04 MP/cm2
    Moiré control no AA filter no AA filter
    Movie Capability 1080/60p Video 4K/30p Video
    ISO Setting 80 - 3,200 ISO 80 - 3,200 ISO
    ISO Boost no Enhancement 80 - 6,400 ISO
    Image Processor DIGIC 6 BIONZ X
    Screen Specs Canon SX730 Sony HX99
    Viewfinder Type no viewfinder Electronic viewfinder
    Viewfinder Field of View 100%
    Viewfinder Resolution 638k dots
    LCD Framing Live View Live View
    Rear LCD Size 3.0inch 3.0inch
    LCD Resolution 922k dots 922k dots
    LCD Attachment Tilting screen Tilting screen
    Touch Input no Touchscreen Touchscreen
    Shooting Specs Canon SX730 Sony HX99
    Focus System Contrast-detect AF Contrast-detect AF
    Continuous Shooting 5.9 shutter flaps/s 10 shutter flaps/s
    Fill Flash Built-in Flash Built-in Flash
    Storage Medium SDXC cards MS or SDXC cards
    Single or Dual Card Slots Single card slot Single card slot
    UHS card support no UHS-I
    Connectivity Specs Canon SX730 Sony HX99
    External Flash no Hotshoe no Hotshoe
    USB Connector USB 2.0 USB 2.0
    HDMI Port micro HDMI micro HDMI
    Wifi Support Wifi built-in Wifi built-in
    Near-Field Communication NFC built-in NFC built-in
    Bluetooth Support Bluetooth built-in Bluetooth built-in
    Body Specs Canon SX730 Sony HX99
    Battery Type Canon NB-13L Sony NP-BX1
    Battery Life (CIPA)250 shots per charge370 shots per charge
    In-Camera Charging USB charging USB charging
    Body Dimensions 110 x 64 x 40 mm
    (4.3 x 2.5 x 1.6 in)
    102 x 58 x 36 mm
    (4.0 x 2.3 x 1.4 in)
    Camera Weight 300 g (10.6 oz) 242 g (8.5 oz)
    logo
    Check SX730 offers at
    ebay.com
    logo
    Check HX99 offers at
    ebay.com

    Did you notice an error on this page? If so, please get in touch, so that we can correct the information.

    You are here Home  »  CAM-parator  »  Canon SX730 vs Sony HX99