KP vs K1 Image Quality

Hi all, long time since I posted on here, hope you're all OK.

After owning a K-5iis for 8 or 9 years and and K3 for 7 years, I've recently acquired both a KP and a K1 (still have the K-5iis and K3, but probably will sell the iis).

There's no doubt the K1 is a beast of a camera, a pleasure to use and superb image quality, but is it that much better than a KP?

I don't intend to keep both cameras, so I've been using them side by side and doing some controlled tests with the same lenses and a tripod to compare the IQ of the K1 and the KP. I know this is apples and pears, but I'm interested all the same. I have to say, I'm amazed by how good the KP is and how close it comes to the K1 for image quality, despite the lower pixel count. I would say that up to 3200 ISO (the highest I will shoot), the K1 is a bit better, but it's by mere fractions. I would even say the KP produces images which are a hair sharper! The KP is definitely leagues ahead of my K3. All of my test images were shot in RAW with no sharpening applied, the only thing I did with them was to equalise the white balance.

Does anyone else own both the KP and the K1 and if so, what do you think about the comparative IQ between the two? My thought process at the moment is to sell the K1 as it would require a big investment in lenses, whereas I already own a lot of lenses that I can use with the KP. Another consideration is that I find the KP better in live view mode, especially for critical manual focusing, as it has the 'edge peaking' option that the K1 doesn't have. This makes it a breeze to get critically sharp focus on any subject.

I wold be interested in hearing thoughts from others on this, particularly KP and K1 owners.

Regards
David

They're both very close in terms of IQ for most uses in my opinion. I kept the K-1 and sold the KP because I have a number of FF lenses and I wanted to keep the slightly larger FOV available using the K-1 sensor.

The KP is very good at being a compact camera with high end features (in Pentax terms) so it does most of the stuff the K-1 does while being lighter, (faster) and cheaper.

It's not just about resolution, it's also about fine gradation, noise and the depth of field. These may be subtle effects but they may be important to some photographers. There might be anargument for the K-1 for landscape and portrait and the KP for sports and wildlife. If size of camera and lenses is important, then the KP has it.

I'm not sure it's an either/or because both formats have their own benefits and drawbacks and we might need both depending on what we're shooting at any particular time.

Hi John

I can't really justify keeping both (might have a quiet word with the other half), the noise is a factor, but at ISO 3200 the KP is very close in performance to the K1. Above this level, the K1 has a clear advantage. The depth of field of course cannot be replicated on a crop sensor camera. I suppose the main point of my post was to highlight what a great job Pentax did with the KP, for what it is and what it costs in comparison to a K1, it really is a superb piece of kit. It is leagues ahead of the K3 and the K-5iis in low light, which is important to me.

If I keep the K1 I will look for a set of vintage lenses to partner it, I already have a fair few, but need to think carefully about which ones will work best with it. I did pick up a rarity on ebay last week, a Sigma 24-135 AF lens, very scarce in the Pentax mount and this seems to work well with it. It's a full frame zoom, well worth seeking out if you can find one.

Regards
David

If you keep the K1 then try some of the Meyer Optik glass. Only thing to watch for is oil on the iris - it can spring blades loose if they stick together! There is certainly no need to pay big money on modern stuff. The Takumar 3.5/200 works amazingly well with it. I still use the K5 for macro because it's perfect for that job.

I am a bit confused when you say the K1 doesn’t have edge peaking for live view manual focusing, check the menu because it does. I use it mostly when focus stacking but it is best switched off for night shots.

From a purely technical aspect some figures:

Sensor Area of K1 is 862mm2, nominal M.P 36.4, pixel density 4.24MP per cm2

Sensor Area of K-3II is 371mm2, nominal M.P 24, pixel density 6.66MP per cm2.

What effect(s) can one expect these figures to have on relative image quality?

Philip

The K1 does have focus peaking, but the KP has both normal focus peaking and edge peaking, which is a different kettle of fish altogether. This mode shows a grey image with only edge highlights visible, whereas the normal focus peaking shows the image in colour. The KP version is much easier to focus and for that reason the peaking on the KP is far superior to that on the K1.

Regards
David

As a 'general rule of thumb'...all other things being equal, one would expect sensors with a lower pixel density to produce images with less 'noise'...i.e they would have a higher signal to noise ratio which would result in 'cleaner'...more faithfully reproduced images.

The Pentax 645z Medium Format sensor although much larger than a FF sensor (from the K-1 for example)
has a lower pixel density (3.53MP per cm2 compared to 4.24 MP per cm2 from K-1) even though it has a higher number of pixels in total.

Both the KP and K-1 are of a similar age technology wise so wouldn't expect advances in sensor technology to alter things much here.

Very basic explanation I know and other things do affect overall image quality.

David

I currently have both. I have not done any straight comparison shot but feel Image quality wise ithe K1 has a slight adavantage but do not feel the difference is significant. What i feel does work in the K1's advantage is how the focus falls of as a result of larger sensor, on the other hand it can be nice to get the larger depth of field with out using a tripod on the KP

Like youself i am not sure if i can justify keeping both. I enjoy using the KP as its smaller, I mostly use it with the LTD lenses which makes the whole system light to use. There is currently no wide angle ltd lens for the K1 so i find myself using the DFA zooms which are quite bulky in comparison. Unfortunatley due to the pandemic if have not had chance to test the K1 as much as i would like too, especialy for stuff like portaiture.

Thanks for all the input so far, it's been helpful

As an aside, now I have the K1, I'm on the lookout for a wide angle lens that can do justice to the K1's sensor. When I mean wide angle, I mean a prime lens and it will be a vintage one as I can't afford a DFA lens. So, I'm looking for suggestions, based on experience, in the 20 to 28mm focal range, lenses that can be sharp across the frame and will work well on a K1 without vignetting. I already have a K series 35mm f/3.5, a M series 28mm f3.5 and I have a K series 24mm f/2.8 on the way. I also have a Sigma 24mm Super-wide, but given lockdown I haven't yet had the chance to really test these lenses.

If anyone can point me in the direction of a wide-angle vintage lens that will really do the K1 justice, please let me know. I don't care if it is AF or MF.

Thanks in advance!

Regards
David

If it does not have to be Pentax have a look out for a Tokina 17mm https://www.pentaxforums.com/userreviews/tokina-sl-17-17mm-f-3-5.html

I know you have asked about a prime lens, but I have found the SMC Pentax-FA 20-35mm f/4 to work very well with the K-1. It is also very compact, whilst still avoiding any significant vignetting.

If it has to be a prime there's the SMC Pentax-FA 20mm F2.8. It gets a 9.26/10 over at PF.