We may earn revenue from the products available on this page and participate in affiliate programs. Learn more ›

Editor’s note: Since we launched our Buying Guide last fall we’ve been soliciting user reviews on cameras and lenses. The aim is to leverage the smarts and experience of our user base of photo enthusiasts, which we think is the most knowledgeable around. Most so far have been fairly short and to the point. But Phil Leese’s review of the Pentax K100D digital SLR is so thorough and exhaustive we felt it needed to be pulled out into the main site. We encourage you to check out our other user reviews on hundreds of cameras and lenses, or write your own.

I’ve owned SLR’s for 30 years starting with screw mount lenses and moving to Pentax K mount. In the last 5 years I became interested in digital photography owning a Canon A200 and Konica Minolta Dimage Z3. We’ve also got 5 other digital compacts in the household including new Samsung and Fuji 6MP models.
The KM Z3 is a great camera with a 12 times optical zoom and anti shake sensor but I was a little disappointed with noise in the dark areas of some pictures. This could be kept to a reasonable level if ISO was fixed at 50 but this limits flexibility when the sun isn’t shining.
I’d thought about buying a digital SLR for some time but couldn’t really justify the expense over what seemed to be minor benefits. However, when I discovered that the K100D would work with my old K mount lenses and my manual flash guns and it had shake reduction I became very interested.


Before purchase my local dealer (Jessops) ordered a K100D from their warehouse for me to look at. I had already checked many reviews and downloaded sample images for a number of cameras. These are my opinions;

Nikon D40 – Pleasing, well saturated images but a tendency to slightly over expose
Pentax K100D – Pleasant and well saturated but a tendency to slightly underexpose, very low noise. Surprisingly sharp for a 6MP camera and much sharper than the *ist models.
Olympus E500 – Softer images than the Pentax and Nikon which are 6MP
Olympus E400 – No better than the Pentax so to me not worth the very high premium. Just shows that the number of megapixels is only part of the story.
Sony Alpha A-100 – Very good but the difference to me isn’t worth the extra money
Canon Rebel XTi – Very good but the difference to me isn’t worth the extra money

My conclusion was that Olympus made a big mistake using the four thirds sensor. With current technology it’s too small to cram in so many photo receptors all receiving proportionately less light than the equivalent APS-C sensors on other cameras. Consequently they have to turn up the amplification which increases noise then apply heavy noise reduction to hide it but that just softens the image, so what’s the point in having 10 megapixels if you soften it down to the resolution of 6 megapixels? The Sony and Canon are very good but quite a bit more expensive. The Pentax images could be blown up to A4 and it would be very difficult to tell the difference from a 10MP camera. At A3 the images would still be very pleasing and useable. So for my uses it’s not worth paying the extra. The Nikon D40 is very appealing but can occasionally burn out highlights (adjusting the EV compensation would probably cure this). It also doesn’t have anti-shake (unless you spend a lot on lenses). So for me the K100D with it’s image quality, lens compatibility and anti shake for a comparatively low price was a no brainer.


If you are upgrading from a digital compact then you will find a significant difference in size and weight. Digital SLR’s are big, even bigger than my film SLR. However, the K100D is small to medium size for a digital SLR. At first I was unsure that I would like this but after using it you get used to it. On the positive side the K100D is very sturdy being made from a steel chassis and a strong plastic body. The battery compartment is shaped to provide good grip with a rubberised coating. The mechanical operation of the lens (18-55mm) is also good and on the whole the camera/lens package feels as though it will stand up to a fair amount of rough treatment and hard work. The controls are well positioned and easy to get used to.


There are a large number of shooting modes, the ones likely to be used the most are on the control dial. The fully automatic mode selects what it believes to be the most appropriate scene mode. I tried this and always got a decent picture but I prefer to use Program, Aperture priority or Manual. Aperture and shutter speed are adjusted using a thumbwheel on the rear of the camera. I like the viewfinder. It displays a useful range of info including the number of stops + or – adjustment required in manual mode.

I have a number of earlier Pentax K mount lenses i.e., open aperture metering and no ‘A’ setting. These will work in aperture priority mode but only at full aperture ie the lens isn’t stopped down. That’s fine for my 80-200mm which is f4.5. I still get an acceptable picture. I also planned on using my Chinon 50mm for portraits which is f1.9. To use the full aperture range you need to use manual mode (set the menu to allow use of aperture ring and depth of field preview to stop down the lens). When you use the depth of field preview (on the on/off switch) the camera stops the lens down and gives you a meter reading. You can adjust the exposure with the thumbwheel (or aperture ring) while stopped down. Not bad once you’ve got used to it and it allows you to use all those lenses you have.


The 2.5 inch LCD is excellent. Pictures can be set to display for varying periods following capture. It will zoom up to 12x. The play mode has all the usual features including capture info and histogram. Despite some reviews criticising some of the menu texts their meanings seemed obvious to me and anyway they are easy to check out in the user manual which is pretty good.

All the controls you’d expect can be set in the menus but one feature I really like is the auto ISO range. You can set this at any single ISO (200-3200) or set a range for the camera to select from. Image noise is very low on this camera even up to ISO 800 so I tend to use a range of 200 to 800. This in combination with the shake reduction sensor allows you to take photos in low light without flash. I have been surprised at how good these pictures are.


That large LCD does eat your batteries so keep its use to a minimum. You can get a set of 2600 NiMH rechargeables from ASDA for a tenner.


I’ve tested the shake reduction with 50mm, 18-55mm, 80-200mm and 80-200mm with a 2x converter (that’s 200x2x1.5 = 600mm equiv. on a film slr). My Minolta has anti-shake with a 12x zoom so I had something to compare against. For older K mount lenses the camera asks you to confirm the focal length when you switch on. Shake reduction is definitely worth having, I have taken shots at ¼ of a second and got a usable picture. Obviously, your shutter speed needs to match your subject but with people for example you can easily take shots indoors without flash (auto white balance doesn’t cope that well with indoor lighting, make sure you switch it over in the function menu). I also tested the 200mm zoom with 2x converter taking a picture of a tree in the distance at 1/60th handheld. This picture is really sharp even blown up quite a lot. In conclusion, it seems to be as effective as the Minolta. The big plus is that the shake reduction uses a floating sensor in the camera body; it works with any lens, even my old manual focus ones. You don’t get that with Nikon and Canon.


The inbuilt flash was a pleasant surprise. It generally gives excellent pictures. You can set it to pop up automatically if the exposure requires it or leave it as manual and decide yourself when to use flash. It can get fooled by reflective objects which tend to make it underexpose a little but on the whole it provides well exposed pictures without redeye (and that’s without redeye settings on). It’s quite powerful and due to the camera’s low noise you can use an ISO setting up to 800 giving you a very effective tool.

You can get the flash to work with your manual lenses in manual shooting mode. The flash will fire at full output so set the appropriate aperture. I soon got used to guessing the correct aperture based on the distance although you could work it out based on the guide number.

I have 3 flash guns from years gone by including a Chinon zoom head, a Chinon bracket mounted and a Cullman CX 35 which I wanted to use rather than buy a new one. The switching voltage must not be more than around 30 volts or you’ll damage the camera. I managed to find this data for the Chinon zoom and the Cullman on the web. You must also ensure that any dedicated contacts don’t work. I unscrewed the foot on the Chinon and snipped the wire for the single dedicated pin. The Cullman uses an interchangeable foot which slides off. Using my manual SLR to fire it and through a process of elimination I taped over all the contacts between the foot and the base of the flash to leave just the ones that trigger the flash (You can switch the foot to manual but I still got a very low voltage across the contacts).

These flashes are automatic thyristor types you just set the camera’s shutter speed/aperture in manual mode to the auto setting on the flashgun (eg f/8) and away you go. These flash guns work extremely well and I’ve saved myself a bundle of cash.


Auto focus with the Pentax 18-55mm is quick and even works well in low light. It might hunt on the odd occasion if it’s a low light low contrast scene but it always focuses. I believe the flash can provide strobed light to assist but I haven’t needed it so far. My Minlota Z3 would just give up in these situations. You can turn the manual focus ring at any time. The camera does use it’s 11 focus zones and gives you a red marker on screen where it chose to focus. Manual focus was a dream with my old K mount lenses as the matte viewfinder is very effective and the camera’s own focusing system gives you both audible and visual focus confirmation.


My original plan was to buy the K100D body and use my old lenses until I had saved up for a top quality 18-200 zoom. However, I could get the package with the Pentax 18-55mm for only £20 more than the body only, a no brainer. So how good is this bundled lens. My main concern was that it might provide a resolution lower than the sensor could capture. I also tested the 50mm Chinon and 80-200mm Vivitar. The review sites generally agreed that around 1500 lines per picture height was available and that ‘s what I got with all three lenses. In other words all 3 lenses are capable of resolving detail to the sensor’s limit. The 6mp sensor in this camera delivers far more lph than either the Fuji or Samsung 6mp compacts.

I have left the camera at the delivered settings except for image tone which I set to natural rather than bright.

I shot using RAW and jpeg with no difference between the level of detail resolved. However, the jpegs do display some very minor colour moiré which isn’t there in raw-until you apply the camera settings. I haven’t had time to check out what causes this but suspect it could be the sharpening. In any case this is so minor it won’t impact on “real” pictures.

I’ve tried the multi segment and centre weighted metering and found both to be good although I think the centre weighting area is too small. My only other comment would be that there is the occasional slight under exposure from both which was hard to predict. I thought maybe half a stop compensation might cure it but it’s not consistent. This camera uses the same sensor as the Nikon D40 which I checked out before buying the Pentax. Image samples from the Nikon I found on the web were very good but there was the occasional burn out of highlights. The Pentax is maybe geared to avoiding burn out, the darker detail can be recovered using editing software. The dynamic range of the sensor could be a factor but you have to pay considerably more to go to the next level.

What pleases me the most about the images from this camera is it’s very low noise. It seems as though the camera doesn’t have to apply much noise reduction or sharpening. This leaves pictures which are detailed and natural. Compared to say a 10mp Olympus I’d take the Pentax every time.

If you submit pictures to agencies then the images respond well to interpolation (although of course this doesn’t pull out any extra detail). I don’t know what algorithm is used but the Pentax Raw converter software will save at larger image sizes and produce really good results. I’ve also tried interpolating jpegs using various algorithms (cubic etc) and the results are ok.

The RAW processing software seems pretty good but I haven’t used it much to be honest as the jpeg’s are really good straight from the camera (natural image tone setting). Contrast is very realistic and adjusting with levels or curves isn’t really needed in most pictures.

If you are taking a serious set of pictures use RAW, it leaves your options open but as a default the conversion software will apply the camera jpeg settings if you want it to. It’s a good base point to compare against. However, jpeg’s from this camera are really natural (use the natural image tone setting) and don’t lose any detail as far as I can tell.

In my view if you have shot jpeg’s you shouldn’t have to do much processing on the PC. They should be right first time and that’s pretty much how they are from the K100D. Beyond all the measurements you still have to make a subjective judgement and I like pictures taken on this camera, they look as good as you can get at this price.


•Uses AA batteries
•Compatible with most K mount lenses ever made
•Works with dedicated and basic flash guns
•Controls are easy to learn
•Can be used in many modes from full manual to point and shoot
•Shake reduction is very effective
•Image noise is very low
•Minimal in camera processing (my guess) ensures fine detail is retained.
•Tough body.
•Good inbuilt flash
•Great value compared to the competion. Nothing at the price offers better images, then add shake reduction, a good bundled lens and backward lens compatabilty for a well thought out SLR.

•Small to medium for a digital SLR but (in my view) all digital SLR’s are a tad too big and heavy.
•Comparatively speaking a good buy but digital SLR’s should not cost this much.

That’s it..

-Phil Leese

Note: User Reviews do not reflect the opinions of the editors of User Reviews should be used for informational purposes only to help you make an informed choice, not as a definitive authority on what camera or lens is most appropriate for you.