HP Photosmart 945 vs. HP Photosmart R717

Comparison

change cameras »

HP Photosmart 945

HP Photosmart R717

check price »

Megapixels

5.10

6.20

Max. image resolution

2608 x 1952

2864 x 2160

Sensor

Sensor type

CCD

Sensor size

1/1.8" (~ 7.11 x 5.33 mm)

Sensor resolution

2604 x 1958

2871 x 2159

Diagonal

8.89 mm

Sensor size comparison

Sensor size is generally a good indicator of the quality of the camera. Sensors can vary greatly in size. As a general rule, the bigger the sensor, the better the image quality.

Bigger sensors are more effective because they have more surface area to capture light. An important factor when comparing digital cameras is also camera generation. Generally, newer sensors will outperform the older.

Learn more about sensor sizes »

Actual sensor size

Note: Actual size is set to screen → change »

	vs
1	:	1
(ratio)

HP Photosmart 945		HP Photosmart R717

Surface area:

37.90 mm²

Difference: 0 mm² (0%)

945 and R717 sensors are the same size.

Note: You are comparing cameras of different generations. There is a 2 year gap between HP 945 (2003) and HP R717 (2005). All things being equal, newer sensor generations generally outperform the older.

Pixel pitch

2.73 µm

2.48 µm

Pixel pitch tells you the distance from the center of one pixel (photosite) to the center of the next. It tells you how close the pixels are to each other.

The bigger the pixel pitch, the further apart they are and the bigger each pixel is. Bigger pixels tend to have better signal to noise ratio and greater dynamic range.

Difference: 0.25 µm (10%)

Pixel pitch of 945 is approx. 10% higher than pixel pitch of R717.

Pixel area

7.45 µm²

6.15 µm²

Pixel or photosite area affects how much light per pixel can be gathered. The larger it is the more light can be collected by a single pixel.

Larger pixels have the potential to collect more photons, resulting in greater dynamic range, while smaller pixels provide higher resolutions (more detail) for a given sensor size.

Relative pixel sizes:

Pixel area difference: 1.3 µm² (21%)

A pixel on HP 945 sensor is approx. 21% bigger than a pixel on HP R717.

Pixel density

13.41 MP/cm²

16.31 MP/cm²

Pixel density tells you how many million pixels fit or would fit in one square cm of the sensor.

Higher pixel density means smaller pixels and lower pixel density means larger pixels.

Difference: 2.9 µm (22%)

HP R717 has approx. 22% higher pixel density than HP 945.

To learn about the accuracy of these numbers, click here.

Specs

HP 945

HP R717

Crop factor

4.87

Total megapixels

Effective megapixels

Optical zoom

8.1x

Digital zoom

Yes

ISO sensitivity

Auto, 100, 200, 400

Auto, 50, 100, 200, 400

RAW

Manual focus

Normal focus range

50 cm

Macro focus range

10 cm

14 cm

Focal length (35mm equiv.)

37 - 300 mm

39 - 117 mm

Aperture priority

Yes

Max. aperture

f2.8 - f3.1

f2.8 - f4.9

Max. aperture (35mm equiv.)

f13.6 - f15.1

f13.6 - f23.9

Metering

Centre weighted, Matrix, Spot

Exposure compensation

±3 EV (in 1/3 EV steps)

Shutter priority

Yes

Min. shutter speed

16 sec

Max. shutter speed

1/2000 sec

Built-in flash

External flash

Viewfinder

Electronic

Optical (tunnel)

White balance presets

Screen size

1.8"

Screen resolution

180,000 dots

130,572 dots

Video capture

Max. video resolution

Storage types

MultiMedia, Secure Digital

USB

USB 1.0

HDMI

Wireless

GPS

Battery

AA (4) batteries (NiMH recommended)

HP Lithium-Ion rechargeable supplied

Weight

400 g

180 g

Dimensions

123 x 85 x 85 mm

96 x 60 x 35 mm

Year

2003

2005

Choose cameras to compare

Popular comparisons:

Diagonal

Diagonal is calculated by the use of Pythagorean theorem:

Diagonal = √

w² + h²

where w = sensor width and h = sensor height

HP 945 diagonal

The diagonal of 945 sensor is not 1/1.8 or 0.56" (14.1 mm) as you might expect, but approximately two thirds of that value - 8.89 mm. If you want to know why, see sensor sizes.

w = 7.11 mm
h = 5.33 mm

Diagonal = √

7.11² + 5.33²

= 8.89 mm

HP R717 diagonal

The diagonal of R717 sensor is not 1/1.8 or 0.56" (14.1 mm) as you might expect, but approximately two thirds of that value - 8.89 mm. If you want to know why, see sensor sizes.

w = 7.11 mm
h = 5.33 mm

Diagonal = √

7.11² + 5.33²

= 8.89 mm

Surface area

Surface area is calculated by multiplying the width and the height of a sensor.

945 sensor area

Width = 7.11 mm
Height = 5.33 mm

Surface area = 7.11 × 5.33 = 37.90 mm²

R717 sensor area

Width = 7.11 mm
Height = 5.33 mm

Surface area = 7.11 × 5.33 = 37.90 mm²

Pixel pitch

Pixel pitch is the distance from the center of one pixel to the center of the next measured in micrometers (µm). It can be calculated with the following formula:

Pixel pitch =	sensor width in mm	× 1000
	sensor resolution width in pixels

945 pixel pitch

Sensor width = 7.11 mm
Sensor resolution width = 2604 pixels

Pixel pitch =	7.11	× 1000	= 2.73 µm
	2604

R717 pixel pitch

Sensor width = 7.11 mm
Sensor resolution width = 2871 pixels

Pixel pitch =	7.11	× 1000	= 2.48 µm
	2871

Pixel area

The area of one pixel can be calculated by simply squaring the pixel pitch:

Pixel area = pixel pitch²

You could also divide sensor surface area with effective megapixels:

Pixel area =	sensor surface area in mm²
	effective megapixels

945 pixel area

Pixel pitch = 2.73 µm

Pixel area = 2.73² = 7.45 µm²

R717 pixel area

Pixel pitch = 2.48 µm

Pixel area = 2.48² = 6.15 µm²

Pixel density

Pixel density can be calculated with the following formula:

Pixel density = (	sensor resolution width in pixels	)² / 1000000
	sensor width in cm

One could also use this formula:

Pixel density =	effective megapixels × 1000000	/ 10000
	sensor surface area in mm²

945 pixel density

Sensor resolution width = 2604 pixels
Sensor width = 0.711 cm

Pixel density = (2604 / 0.711)² / 1000000 = 13.41 MP/cm²

R717 pixel density

Sensor resolution width = 2871 pixels
Sensor width = 0.711 cm

Pixel density = (2871 / 0.711)² / 1000000 = 16.31 MP/cm²

Sensor resolution

Sensor resolution is calculated from sensor size and effective megapixels. It's slightly higher than maximum (not interpolated) image resolution which is usually stated on camera specifications. Sensor resolution is used in pixel pitch, pixel area, and pixel density formula. For sake of simplicity, we're going to calculate it in 3 stages.

1. First we need to find the ratio between horizontal and vertical length by dividing the former with the latter (aspect ratio). It's usually 1.33 (4:3) or 1.5 (3:2), but not always.

2. With the ratio (r) known we can calculate the X from the formula below, where X is a vertical number of pixels:

(X × r) × X = effective megapixels × 1000000 →

X = √	effective megapixels × 1000000
	r

3. To get sensor resolution we then multiply X with the corresponding ratio:

Resolution horizontal: X × r
Resolution vertical: X

945 sensor resolution

Sensor width = 7.11 mm
Sensor height = 5.33 mm
Effective megapixels = 5.10

r = 7.11/5.33 = 1.33

X = √	5.10 × 1000000	= 1958
	1.33

Resolution horizontal: X × r = 1958 × 1.33 = 2604
Resolution vertical: X = 1958

Sensor resolution = 2604 x 1958

R717 sensor resolution

Sensor width = 7.11 mm
Sensor height = 5.33 mm
Effective megapixels = 6.20

r = 7.11/5.33 = 1.33

X = √	6.20 × 1000000	= 2159
	1.33

Resolution horizontal: X × r = 2159 × 1.33 = 2871
Resolution vertical: X = 2159

Sensor resolution = 2871 x 2159

Crop factor

Crop factor or focal length multiplier is calculated by dividing the diagonal of 35 mm film (43.27 mm) with the diagonal of the sensor.

Crop factor =	43.27 mm
	sensor diagonal in mm

945 crop factor

Sensor diagonal in mm = 8.89 mm

Crop factor =	43.27	= 4.87
	8.89

R717 crop factor

Sensor diagonal in mm = 8.89 mm

Crop factor =	43.27	= 4.87
	8.89

35 mm equivalent aperture

Equivalent aperture (in 135 film terms) is calculated by multiplying lens aperture with crop factor (a.k.a. focal length multiplier).

945 equivalent aperture

Crop factor = 4.87
Aperture = f2.8 - f3.1

35-mm equivalent aperture = (f2.8 - f3.1) × 4.87 = f13.6 - f15.1

R717 equivalent aperture

Crop factor = 4.87
Aperture = f2.8 - f4.9

35-mm equivalent aperture = (f2.8 - f4.9) × 4.87 = f13.6 - f23.9

Enter your screen size (diagonal)

My screen size is inches

Actual size is currently adjusted to screen.

If your screen (phone, tablet, or monitor) is not in diagonal, then the actual size of a sensor won't be shown correctly.