Nikon D40 vs Pentax 645D

The Nikon D40 and the Pentax 645D are two digital cameras that were revealed to the public, respectively, in November 2006 and March 2010. Both are DSLR (Digital Single Lens Reflex) cameras that are based on an APS-C (D40) and a medium format (645D) sensor. The Nikon has a resolution of 6 megapixels, whereas the Pentax provides 39.5 MP.

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

Headline Specifications

Nikon D40		Pentax 645D
Digital single lens reflex		Digital single lens reflex
Nikon F mount lenses		Pentax 645 mount lenses
6 MP – APS-C sensor		39.5 MP – Medium Format sensor
no Video		no Video
ISO 200-1,600 (200 - 3,200)		ISO 100-1,600
Optical viewfinder		Optical viewfinder
2.5" LCD – 230k dots		3.0" LCD – 921k dots
Fixed screen (not touch-sensitive)		Fixed screen (not touch-sensitive)
2.5 shutter flaps per second		1.1 shutter flaps per second
not weather sealed		Weathersealed body
470 shots per battery charge		800 shots per battery charge
124 x 94 x 64 mm, 522 g		156 x 117 x 119 mm, 1480 g

Check D40 offers at
ebay.com
Check 645D offers at
ebay.com

Going beyond this snapshot of core features and characteristics, what are the differences between the Nikon D40 and the Pentax 645D? 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.

Body comparison

The side-by-side display below illustrates the physical size and weight of the Nikon D40 and the Pentax 645D. 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.

If the front view area (width x height) of the cameras is taken as an aggregate measure of their size, the Pentax 645D is considerably larger (57 percent) than the Nikon D40. Moreover, the 645D is substantially heavier (184 percent) than the D40. It is noteworthy in this context that the 645D is splash and dust-proof, while the D40 does not feature any corresponding weather-sealing.

The above size and weight comparisons are to some extent incomplete since they do not consider the interchangeable lenses that both of these cameras require. Hence, you might want to study and compare the specifications of available lenses in order to get the full picture of the size and weight of the two camera systems.

Concerning battery life, the D40 gets 470 shots out of its Nikon EN-EL9 battery, while the 645D can take 800 images on a single charge of its Pentax D-LI90 power pack.

The table below summarizes the key physical specs of the two cameras alongside a broader set of comparators. If you would like to visualize and compare a different camera combination, you can navigate to the CAM-parator app and make your selection from a broad list of cameras there.

Body Specifications

		Camera Model	Camera Width	Camera Height	Camera Depth	Camera Weight	Battery Life	Weather Sealing	Camera Launch	Launch Price (USD)	Street Price
1.		Nikon D40	124 mm	94 mm	64 mm	522 g	470	n	Nov 2006	499	ebay.com
2.		Pentax 645D	156 mm	117 mm	119 mm	1480 g	800	Y	Mar 2010	9,995	ebay.com
3.		Canon 1D Mark IV	156 mm	157 mm	80 mm	1230 g	1500	Y	Oct 2009	4,999	ebay.com
4.		Canon 1D X	158 mm	168 mm	83 mm	1551 g	1120	Y	Oct 2011	6,799	ebay.com
5.		Leica S Typ 006	160 mm	120 mm	80 mm	1260 g	..	Y	Sep 2012	21,950	ebay.com
6.		Nikon D3S	160 mm	157 mm	88 mm	1240 g	4200	Y	Oct 2009	5,199	ebay.com
7.		Nikon D40X	124 mm	94 mm	64 mm	522 g	520	n	Mar 2007	729	ebay.com
8.		Nikon D50	133 mm	102 mm	76 mm	620 g	400	n	Apr 2005	749	ebay.com
9.		Nikon D60	126 mm	94 mm	64 mm	522 g	500	n	Jan 2008	629	ebay.com
10.		Nikon D70	140 mm	111 mm	78 mm	679 g	400	n	Jan 2004	999	ebay.com
11.		Nikon D70s	140 mm	111 mm	78 mm	679 g	500	n	Apr 2005	899	ebay.com
12.		Nikon D80	132 mm	103 mm	77 mm	668 g	600	n	Aug 2006	999	ebay.com
13.		Nikon D3000	126 mm	97 mm	64 mm	536 g	500	n	Jul 2009	599	ebay.com
14.		Nikon D3100	124 mm	96 mm	75 mm	505 g	550	n	Aug 2010	599	ebay.com
15.		Nikon D3300	124 mm	98 mm	76 mm	430 g	700	n	Jan 2014	499	ebay.com
16.		Nikon D3400	124 mm	98 mm	76 mm	445 g	1200	n	Aug 2016	499	ebay.com
17.		Pentax 645Z	156 mm	117 mm	123 mm	1550 g	650	Y	Apr 2014	8,499	ebay.com
Note: Measurements and pricing do not include easily detachable parts, such as add-on or interchangeable lenses or optional viewfinders.
Convert to Imperial

The price is, of course, an important factor in any camera decision. The manufacturer’s suggested retail prices give an idea on the placement of the camera in the maker’s lineup and the broader market. The D40 was launched at a markedly lower price (by 95 percent) than the 645D, which puts it into a different market segment. 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 imaging sensor is at the core of digital cameras and its size is one of the main determining factors of image quality. A large sensor will tend to have larger individual pixels that provide better low-light sensitivity, wider dynamic range, and richer color-depth than smaller pixel-units in a sensor of the same technological generation. Moreover, a large sensor camera will give the photographer more control over depth-of-field in the image and, thus, the ability to better isolate a subject from the background. On the downside, larger sensors are more costly to manufacture and tend to lead to bigger and heavier cameras and lenses.

Of the two cameras under consideration, the Nikon D40 features an APS-C sensor and the Pentax 645D a medium format sensor. The sensor area in the 645D is 292 percent bigger. As a result of these sensor size differences, the cameras have a format factor of, respectively, 1.5 and 0.79. The sensor in the D40 has a native 3:2 aspect ratio, while the one in the 645D offers a 4:3 aspect.

With 39.5MP, the 645D offers a higher resolution than the D40 (6MP), but the 645D has smaller individual pixels (pixel pitch of 6.06μm versus 7.85μm for the D40). Yet, the 645D is a much more recent model (by 3 years and 3 months) than the D40, and its sensor will have benefitted from technological advances during this time that enhance the light gathering capacity of its pixel-units. Coming back to sensor resolution, it should be mentioned that the 645D has no anti-alias filter installed, so that it can capture all the detail its sensor resolves.

The resolution advantage of the Pentax 645D implies greater flexibility for cropping images or the possibility to print larger pictures. The maximum print size of the 645D for good quality output (200 dots per inch) amounts to 36.3 x 27.2 inches or 92.3 x 69.1 cm, for very good quality (250 dpi) 29.1 x 21.8 inches or 73.8 x 55.3 cm, and for excellent quality (300 dpi) 24.2 x 18.1 inches or 61.5 x 46.1 cm. The corresponding values for the Nikon D40 are 15 x 10 inches or 38.2 x 25.4 cm for good quality, 12 x 8 inches or 30.6 x 20.3 cm for very good quality, and 10 x 6.7 inches or 25.5 x 16.9 cm for excellent quality prints.

The Nikon D40 has a native sensitivity range from ISO 200 to ISO 1600, which can be extended to ISO 200-3200. The corresponding ISO settings for the Pentax 645D are ISO 100 to ISO 1600 (no boost).

Technology-wise, both cameras are equipped with CCD (Charged Coupled Device) sensors. Both cameras use a Bayer filter for capturing RGB colors on a square grid of photosensors. This arrangement is found in most digital cameras.

Consistent information on actual sensor performance is available from DXO Mark for many cameras. 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"). Of the two cameras under consideration, the 645D offers substantially better image quality than the D40 (overall score 26 points higher). The advantage is based on 3.6 bits higher color depth, 1.6 EV in additional dynamic range, and 1.2 stops in additional low light sensitivity. The table below summarizes the physical sensor characteristics and sensor quality findings and compares them across a set of similar cameras.

Sensor Characteristics

		Camera Model	Sensor Class	Resolution (MP)	Horiz. Pixels	Vert. Pixels	Video Format	DXO Portrait	DXO Landscape	DXO Sports	DXO Overall
1.		Nikon D40	APS-C	6.0	3008	2000	none	21.0	11.0	561	56
2.		Pentax 645D	Medium Format	39.5	7264	5440	none	24.6	12.6	1262	82
3.		Canon 1D Mark IV	APS-H	16.0	4896	3264	1080/30p	22.8	12.0	1320	74
4.		Canon 1D X	Full Frame	17.9	5184	3456	1080/30p	23.8	11.8	2786	82
5.		Leica S Typ 006	Medium Format	37.5	7500	5000	none	23.9	12.2	824	76
6.		Nikon D3S	Full Frame	12.1	4256	2832	720/24p	23.5	12.0	3253	82
7.		Nikon D40X	APS-C	10.0	3872	2592	none	22.4	11.4	516	63
8.		Nikon D50	APS-C	6.0	3008	2000	none	20.9	10.8	560	55
9.		Nikon D60	APS-C	10.0	3872	2592	none	22.5	11.4	562	65
10.		Nikon D70	APS-C	6.0	3008	2000	none	20.4	10.3	529	50
11.		Nikon D70s	APS-C	6.0	3008	2000	none	20.4	10.3	529	50
12.		Nikon D80	APS-C	10.0	3872	2592	none	22.1	11.2	524	61
13.		Nikon D3000	APS-C	10.0	3872	2592	none	22.3	11.1	563	62
14.		Nikon D3100	APS-C	14.2	4608	3072	1080/24p	22.5	11.3	919	67
15.		Nikon D3300	APS-C	24.0	6000	4000	1080/60p	24.3	12.8	1385	82
16.		Nikon D3400	APS-C	24.0	6000	4000	1080/60p	24.8	13.9	1192	86
17.		Pentax 645Z	Medium Format	51.1	8256	6192	1080/60i	26.0	14.7	4505	101

Feature comparison

Apart from body and sensor, cameras can and do differ across a range of features. The D40 and the 645D are similar in the sense that both have an optical viewfinder. The latter is useful for getting a clear image for framing even in brightly lit environments. The viewfinder in the 645D offers a wider field of view (98%) than the one in the D40 (95%), so that a larger proportion of the captured image is visible in the finder. In addition, the viewfinder of the 645D has a higher magnification (0.78x vs 0.53x), so that the size of the image transmitted appears closer to the size seen with the naked human eye. The table below summarizes some of the other core capabilities of the Nikon D40 and Pentax 645D in connection with corresponding information for a sample of similar cameras.

Core Features

		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.		Nikon D40	optical	n	2.5 / 230	fixed	n	1/4000s	2.5/s	Y	n
2.		Pentax 645D	optical	Y	3.0 / 921	fixed	n	1/4000s	1.1/s	n	n
3.		Canon 1D Mark IV	optical	Y	3.0 / 920	fixed	n	1/8000s	10.0/s	n	n
4.		Canon 1D X	optical	Y	3.2 / 1040	fixed	n	1/8000s	14.0/s	n	n
5.		Leica S Typ 006	optical	Y	3.0 / 922	fixed	n	1/4000s	1.5/s	n	n
6.		Nikon D3S	optical	Y	3.0 / 921	fixed	n	1/8000s	11.0/s	n	n
7.		Nikon D40X	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
8.		Nikon D50	optical	n	2.0 / 130	fixed	n	1/4000s	2.5/s	Y	n
9.		Nikon D60	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
10.		Nikon D70	optical	n	1.8 / 130	fixed	n	1/8000s	3.0/s	Y	n
11.		Nikon D70s	optical	n	2.0 / 130	fixed	n	1/8000s	3.0/s	Y	n
12.		Nikon D80	optical	n	2.5 / 230	fixed	n	1/4000s	3.0/s	Y	n
13.		Nikon D3000	optical	n	3.0 / 230	fixed	n	1/4000s	3.0/s	Y	n
14.		Nikon D3100	optical	n	3.0 / 230	fixed	n	1/4000s	3.0/s	Y	n
15.		Nikon D3300	optical	n	3.0 / 921	fixed	n	1/4000s	5.0/s	Y	n
16.		Nikon D3400	optical	n	3.0 / 921	fixed	n	1/4000s	5.0/s	Y	n
17.		Pentax 645Z	optical	Y	3.2 / 1037	tilting	n	1/4000s	3.0/s	n	n
Note: *) Information refers to the mechanical shutter, unless the camera only has an electronic one.

One difference between the cameras concerns the presence of an on-board flash. The D40 has one, while the 645D does not. While the built-in flash of the D40 is not very powerful, it can at times be useful as a fill-in light.

The Pentax 645D has an intervalometer built-in. This enables the photographer to capture time lapse sequences, such as flower blooming, a sunset or moon rise, without purchasing an external camera trigger and related software.

The D40 writes its imaging data to SDHC cards, while the 645D uses SDXC cards. The 645D features dual card slots, which can be very useful in case a memory card fails. In contrast, the D40 only has one slot.

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 Nikon D40 and Pentax 645D and, in particular, the interfaces the cameras (and selected comparators) provide for accessory control and data transfer.

Input-Output Connections

		Camera Model	Hotshoe Port	Internal Mic / Speaker	Microphone Port	Headphone Port	HDMI Port	USB Port	WiFi Support	NFC Support	Bluetooth Support
1.		Nikon D40	Y	- / -	-	-	-	2.0	-	-	-
2.		Pentax 645D	Y	stereo / -	-	-	-	2.0	-	-	-
3.		Canon 1D Mark IV	Y	stereo / -	Y	-	mini	2.0	-	-	-
4.		Canon 1D X	Y	mono / -	Y	-	mini	2.0	-	-	-
5.		Leica S Typ 006	Y	- / -	-	-	mini	2.0	-	-	-
6.		Nikon D3S	Y	stereo / -	-	-	mini	2.0	-	-	-
7.		Nikon D40X	Y	- / -	-	-	-	2.0	-	-	-
8.		Nikon D50	Y	- / -	-	-	-	2.0	-	-	-
9.		Nikon D60	Y	- / -	-	-	-	2.0	-	-	-
10.		Nikon D70	Y	- / -	-	-	-	1.0	-	-	-
11.		Nikon D70s	Y	- / -	-	-	-	2.0	-	-	-
12.		Nikon D80	Y	- / -	-	-	-	2.0	-	-	-
13.		Nikon D3000	Y	- / -	-	-	-	2.0	-	-	-
14.		Nikon D3100	Y	mono / mono	-	-	mini	2.0	-	-	-
15.		Nikon D3300	Y	mono / mono	Y	-	mini	2.0	-	-	-
16.		Nikon D3400	Y	mono / mono	-	-	mini	2.0	-	-	Y
17.		Pentax 645Z	Y	stereo / mono	Y	-	mini	3.0	-	-	-

Studio photographers will appreciate that the Pentax 645D (unlike the D40) features a PC Sync socket, so that professional strobe lights can be controlled by the camera.

Both the D40 and the 645D have been discontinued, but can regularly be found used on ebay. The D40 was replaced by the Nikon D40X, while the 645D was followed by the Pentax 645Z. Further information on the features and operation of the D40 and 645D can be found, respectively, in the Nikon D40 Manual (free pdf) or the online Pentax 645D Manual.

Review summary

So what is the bottom line? Which of the two cameras – the Nikon D40 or the Pentax 645D – has the upper hand? Is one clearly better than the other? The listing below highlights the relative strengths of the two models.

Advantages of the Nikon D40:

• Better moiré control: Has an anti-alias filter to avoid artificial patterns to appear in images.
• Faster burst: Shoots at higher frequency (2.5 vs 1.1 flaps/sec) to capture the decisive moment.
• More compact: Is smaller (124x94mm vs 156x117mm) and thus needs less room in the bag.
• Less heavy: Is lighter (by 958g or 65 percent) and hence easier to carry around.
• Easier fill-in: Is equipped with a small onboard flash to brighten deep shadow areas.
• More affordable: Was introduced into a lower priced category (95 percent cheaper at launch).
• More heavily discounted: Has been available for much longer (launched in November 2006).

Reasons to prefer the Pentax 645D:

• More detail: Has more megapixels (39.5 vs 6MP), which boosts linear resolution by 151%.
• Maximized detail: Lacks an anti-alias filter to exploit the sensor's full resolution potential.
• Better image quality: Scores substantially higher (26 points) in the DXO overall evaluation.
• Richer colors: Generates noticeably more natural colors (3.6 bits more color depth).
• More dynamic range: Captures a broader range of light and dark details (1.6 EV of extra DR).
• Better low-light sensitivity: Can shoot in dim conditions (1.2 stops ISO advantage).
• More complete view: Has a viewfinder with a larger field of view (98% vs 95%).
• Larger viewfinder image: Features a viewfinder with a higher magnification (0.78x vs 0.53x).
• Easier setting verification: Features a control panel on top to check shooting parameters.
• Larger screen: Has a bigger rear LCD (3.0" vs 2.5") for image review and settings control.
• More detailed LCD: Has a higher resolution rear screen (921k vs 230k dots).
• Easier time-lapse photography: Has an intervalometer built-in for low frequency shooting.
• Longer lasting: Gets more shots (800 versus 470) out of a single battery charge.
• Better sealing: Is splash and dust sealed for shooting in inclement weather conditions.
• Better studio light control: Has a PC Sync socket to connect to professional strobe lights.
• Greater peace of mind: Features a second card slot as a backup in case of memory card failure.
• More modern: Reflects 3 years and 3 months of technical progress since the D40 launch.

If the number of relative strengths (bullet points above) is taken as a guide, the 645D is the clear winner of the contest (17 : 7 points). However, the relative importance of the various individual camera aspects will vary according to personal preferences and needs, so that you might like to apply corresponding weights to the particular features before making a decision on a new camera. A professional wedding photographer will view the differences between cameras in a way that diverges from the perspective of a travel photog, and a person interested in cityscapes has distinct needs from a macro shooter. Hence, the decision which camera is best and worth buying is often a very personal one.

How about other alternatives? Do the specifications of the Nikon D40 and the Pentax 645D place the cameras among the top in their class? Find out in the latest Best DSLR 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 says little about, for example, the shooting experience and imaging performance of the D40 and the 645D in practical situations. At times, user reviews, such as those published at amazon, address these issues in a useful manner, but such feedback is on many occasions incomplete, inconsistent, and unreliable.

Expert reviews

This is where reviews by experts come in. The adjacent summary-table relays the overall verdicts of several of the most popular 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.

Expert Camera Reviews

		Camera   Model	AP   score	CL   score	DCW   score	DPR   score	EPZ   score	PB   score	Camera Launch	Launch Price (USD)	Street Price
1.		Nikon D40	..	81/100	..	+ +	o	4.5/5	Nov 2006	499	ebay.com
2.		Pentax 645D	5/5	..	..	..	..	..	Mar 2010	9,995	ebay.com
3.		Canon 1D Mark IV	5/5	..	..	89/100	..	..	Oct 2009	4,999	ebay.com
4.		Canon 1D X	5/5	..	..	..	4.5/5	4.5/5	Oct 2011	6,799	ebay.com
5.		Leica S Typ 006	..	..	..	..	..	..	Sep 2012	21,950	ebay.com
6.		Nikon D3S	5/5	..	..	89/100	4.5/5	5/5	Oct 2009	5,199	ebay.com
7.		Nikon D40X	..	79/100	..	+ +	4/5	4/5	Mar 2007	729	ebay.com
8.		Nikon D50	..	78/100	..	+ +	4/5	4.5/5	Apr 2005	749	ebay.com
9.		Nikon D60	..	80/100	..	+ +	4/5	4.5/5	Jan 2008	629	ebay.com
10.		Nikon D70	..	..	..	+ +	..	..	Jan 2004	999	ebay.com
11.		Nikon D70s	..	..	..	..	..	5/5	Apr 2005	899	ebay.com
12.		Nikon D80	..	+	..	+ +	o	4.5/5	Aug 2006	999	ebay.com
13.		Nikon D3000	..	+	..	72/100	4/5	4.5/5	Jul 2009	599	ebay.com
14.		Nikon D3100	5/5	+ +	..	72/100	4.5/5	4.5/5	Aug 2010	599	ebay.com
15.		Nikon D3300	3/5	+	..	77/100	4.5/5	4.5/5	Jan 2014	499	ebay.com
16.		Nikon D3400	4/5	+	4/5	76/100	4/5	4.5/5	Aug 2016	499	ebay.com
17.		Pentax 645Z	5/5	..	3.5/5	..	4.5/5	5/5	Apr 2014	8,499	ebay.com
Note: (+ +) highly recommended; (+) recommended; (o) reviewed; (..) not available.

Care should be taken when interpreting the review scores above, though. The ratings are only valid when referring to cameras in the same category and of the same age. A score, therefore, has to be seen in close connection to the price and market introduction time of the camera, and comparing ratings of very distinct cameras or ones that are far apart in terms of their release date have little meaning. Also, kindly note that some of the listed sites have over time developped their review approaches and their reporting style.

Check D40 offers at
ebay.com
Check 645D 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 use the search menu below. Alternatively, you can follow any of the listed hyperlinks for comparisons that others found interesting.

~

Check D40 offers at
ebay.com
Check 645D 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.