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Old Jul 11, 2009, 1:51 AM   #1
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Default Thoughts on K-7, 3200 comparisons

It's a very good thing I wasn't busy today - I couldn't concentrate on work at all. I played with both the K20 and K-7 at lunch, and then a bit this afternoon. Some very random thoughts:

1. The two cameras meter differently. My K20 under-exposes consistently, so usually I just leave it on Ev +.3 most of the time, and that seems to work well (still a bit underexposed, but I don't blow highlights as a rule). The K-7 is much more accurate so I'm going to have to pay attention to some things I used to either ignore or take for granted. When I read "Understanding Exposure" Bryan Peterson mentioned that green was a color you wanted to under-expose by approx. 2/3 stop. It's one of the several colors that will confuse the light meter. I rarely bothered with the K20, usually taking them at either the usual Ev +.3 or without any Ev. I'll need to use an Ev -.3 I think, when taking pictures in forests with lots of green, I think.

2. The in-camera HDR function does work, but you really need a tripod and preferably a remote, too. I think it'll be quite useful for those who don't want to mess with separate software. Output has to be set to jpg. I don't have a tripod bracket yet for my quick release plate, so I rested the camera on a wooden footbridge that wasn't all that level and pushed the shutter. Should have used a remote or something because there was enough movement that the picture came out somewhat blurry. I'll want to try this again using something much sturdier.

Scene as the camera (meter mode set to matrix) decided it should be and jpg straight out of the camera (I know, that stupid irrigation thingy is really in the way, but I didn't have much time at lunch to pick a better spot):



Full sized file here: http://mtngal.zenfolio.com/img/v4/p953847307.jpg .

Here's what the strong HDR setting got me. Again, this is a jpg straight out of the camera and there's a lot wrong with it (dof, shutter speed etc.). I took another picture using the standard HDR setting, but it wasn't quite the same view and there was more obvious camera movement. The HDR effect looked very similar so I won't bother posting it. As you can see, this really is based on 3 separate frames and some sort of tone-mapping done in-camera. And you can see why I highly recommend a tripod - the uneven wood of the footbridge doesn't cut it. As far as the HDR goes, it's effective and it's evened out the tones. I'd be quite happy to start with this picture (assuming it didn't have the blurriness caused by the slight camera movement) and then add some extra contrast in pp as its a bit flat (like many HDR pictures created by software can look, also).



Full sized file: http://mtngal.zenfolio.com/img/v3/p866288827.jpg

Those who like doing HDR with Photomatix will LOVE this camera compared to the K20. The Ev can be set for a +/- 5 stops, not the K20's 2 stops. So you can do a 5 frame exposure bracket using 2 stops between frames and not have the camera say it can't manage it. And that makes a huge difference! Here's what Photomatix did on it's default setting for tone-mapping with 2 stops between each frame and 5 frames:



Full sized file:

Full sized file here: http://mtngal.zenfolio.com/img/v3/p866288827.jpg

I am really going to have fun with the exposure bracketing function! This is one of several features that I knew I was going to want.

A couple of more notes on that - I forgot that the one-push exposure bracketing is a custom menu item and turned off by default. I didn't like having to push the shutter for each frame. It took me a while to find the reference in the K-7's manual once I remembered (it's in small print). The auto bracket function doesn't have the separate button like it did on the K20, but it's easy to access and didn't seem to be any harder to set up/turn off and on.

3. The camera seems much more overwhelming than the K20 did to me. It's going to take me a while to really get comfortable with it since it goes about things differently. It seems more logical, for the most part, but I'm still groping for things at the moment. I need to keep the owners manual near by as I experiment with things - I definitely don't feel comfortable with how the camera goes about ISO settings yet, and the "format SD card" is really buried down in the menus. I use it all the time (I copy the files, then reformat the card in-camera as a way of deleting the files, find it works better that way for me).

4. Metering with manual lenses seems more accurate. I put my old SMC M50mm 1.4 lens on both the K-7 and K20 and took a series of pictures. The K20 metered better than the K10 did, but isn't consistent. The K-7 had exactly the same exposure for all of the apertures I tried, up until f32. Then it was significantly underexposed (the K20 wasn't as badly underexposed for f32). I was doing this inside, and for the last couple of shots I used ISO 3200. You can see below that the K-7 seems to have gone for an overall correct exposure, blowing a few highlights, while the K20 chose to underexpose a bit and not blow the highlights as much.

5. High ISO noise isn't the same. I haven't explored how to change the noise reduction and I don't know what the camera is set to by default. I also don't remember what I have the K20 set to, so these two pictures should be taken as "interesting" rather than as direct comparisons because of that. The smaller versions here don't show it as well as the full sized files do - there's links to them below if you are interested.

K20:



Full sized file at: http://mtngal.zenfolio.com/img/v4/p715197033.jpg

K7:



full sized file at: http://mtngal.zenfolio.com/img/v3/p901623287.jpg

One of the things I did before I ordered the K-7 was to look very closely at the comparison shots at IR for the K-7 and K20. What I see here is very similar to what I saw there, and also on other boards where comparison shots have been posted.

The main thing I hated about the K20's noise at this level is the magenta spots/color noise. There's lots of detail but I found that I couldn't manage to get rid of magenta properly in either Noise Ninja or DxO, without either getting things completely smeared or else getting funny-looking artifacts. The K-7 has mostly gotten rid of that. However, if you look at the full sized files you'll see that there's less detail/more smearing.

However, the K-7 image is useable for small sizes. I took the original, downsized it to about 1400 pixels wide, ran it through Noise Ninja's default settings and then resized it again to 800 pixels wide, to post here. I think it's quite useable, and I wouldn't be afraid to use 3200 as long as I wasn't going to print a poster or crop significantly.
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Old Jul 11, 2009, 10:39 AM   #2
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One more set of pictures, but this doesn't show much about the cameras (or rather maybe it does in a way) - more about the lenses I happened to be using at the time. The pictures are jpg straight out of the camera, but one was set to bright, the other to natural. Metering is different (I hate trying to take comparison shots, I never get everything the same!). As far as what the cameras did - there are differences but the cameras handled things pretty much the same.





100% Crops of the two shots, side by side. While the DA*50-135 is a very good lens wide open, it doesn't quite match the 77 Ltd (granted, the 77 is stopped down a bit).

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Old Jul 11, 2009, 11:23 AM   #3
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I like the auto WB reading on the K7 better (more what fluorescent lighting should look like) in the images of the desk. Interestingly in the area of noise, I can see more noise in the K7 if I look at the visible portion of the monitor in the background. It seems like there is more noise in dark areas on the K7 and less of it in the lighter areas with the K20 exhibiting the opposite. On my recent travels to DC, I tried a ISO 3200 shot inside the Smithsonian...it was very dark in the exhibit area and I ended up with an image that was unusable even after applying Noiseware. I'm looking forward to hearing more about the low light capabilities of the K7!
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Old Jul 11, 2009, 2:36 PM   #4
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Interesting that you should mention the difference - I was looking at the mid-tones and shadowed areas (the large format scanner), didn't think to check the blacks/really darks. The K20 has always been reasonable for noise when black clips. I'll have to pay attention to that more. The big thing with higher ISO pictures is to slightly over-expose the shots (expose to the right as they say), but that's true with any camera.

Some initial conclusions, my own opinion:

1. The basic image quality is the same between the K-7 and K20. Those who are only looking for image quality gains and who already own the K20 would do well to skip the K-7.

2. This camera is all about features. The AWB is significantly improved. The HDR features are fun! The in-camera function does work rather nicely, and those who use Photomatix and the like will love having the extended Ev.

3. Those looking for something smaller and lighter will be happy. I'm getting used to the grip - I rather liked the larger grip on the K20 and thought that the K-7's grip felt a little cramped. But I notice it more with one particular lens, and it doesn't affect how I shoot. While it's not hugely lighter, it's enough lighter to feel better to me.

4. I'm figuring out the interface. It's actually pretty quick and easy to change things, the info button keeps a number of commonly changed items within easy reach (including turning off and on SR). I finally figured out the ISO features. I'm one of those who will just about always find out how NOT to do something before it all works. In the case of changing the ISO - it's very easy and I figured that out right away (push the button and turn the wheel). Your changes stay so that if you have the camera set to auto ISO but then use the button to change to something specific, the camera keeps that setting even if you turn the computer off. I couldn't figure out at first how to easily get it back on auto ISO - answer is to push the ISO and green buttons - duh!
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Old Jul 11, 2009, 5:16 PM   #5
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Thanks for this very informative set of first impressions Mtngal. My K100D has recently started to act up, and I'm considering an upgrade. For my budget, the K20 is available at a very attractive price, but the k7 sounds like a fantastic camera. Decisions, decisions.

Quick question: do you find that the autofocus is significantly faster or more accurate than the K20? Autofocus was one of the few areas I heard some complaints about with the K20, and Pentax says they improved the autofocus on the K7.
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Old Jul 11, 2009, 5:36 PM   #6
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The K-7 is faster all the way around. It writes pictures faster (can't believe how fast it writes a 5 frame auto-focus set). The 50-135 doesn't seem much faster, maybe a bit. The 77 Ltd seems noticeably faster, but that could be more that it doesn't fiddle around fine-tuning as much (or else it's faster at it than the K20). I've only used the 55-300 a bit, don't have a feel for it (which means that it's probably not a huge difference). I've never had a complaint about the K20's AF - I don't shoot sports and my birding is done with a manual focus lens, so I'm not the best judge of it. If this were the only reason why you were interested in the K-7, I'm not convinced that the gains (which seem to be somewhat lens-dependent and with my lenses seem small) would be worth the extra cost over the K20.
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Old Jul 11, 2009, 7:57 PM   #7
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I do not think I will be using ISO 3200 and higher. In field use it is fairly poor. My camer was pre-set to med. noise correction as high ISO default. I re-set to low high ISO noise correction. So far I found the best noise reduction with the least loss of detail achieved in CS$ Camera Raw developer.

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Old Jul 11, 2009, 10:38 PM   #8
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I'm reading all your comment with great interest as I am contemplating either a K7 or K20. You have done a fine job.

I think it will take some time yet for all the K7 users to get more familiar with the camera and have a little more time shooting different subjects before I will be able to make a fair assessment of what direction I should take.

I like the idea of easier access to HDR images but am more interested in auto focus speed and high ISO capabilities. Also for me the larger sensor will give me more crop factor than I now have in the K100D.

I have noticed that the camera strap lugs are offset. I have always used a hand strap and on occasions a binocular shoulder strap. I am wondering if you think they will work with the K7.

Lou
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Old Jul 12, 2009, 1:50 AM   #9
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Lou - I think I'd wait a while if you are seriously contemplating the K-7 over the K20. I don't think there's all that much improvement when it comes to high ISO. I think the AF is faster, but not necessarily enough faster to make it worth the significant increase in cost over the K20. I've never used a hand strap, so don't have an opinion on that.

The big thing is that there's a weird line that suddenly appears for some people after they've used movie mode. I tried a brief video clip today, just to see if it worked. All of a sudden I had the line that others reported. There's some question it might be heat-related (in which case, I'm dead in the water) but I think it's specifically related to the video. So the jury is very much out for this new camera.
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Old Jul 12, 2009, 8:41 AM   #10
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Thanks for posting this timely great comparison Harriet as I was curiously searching the web for a fresh review : ) I also haven't forgotten last year's K10D K20D comparison you posted here!
Anyway, regarding the office shots, especially after downloading the full size images, I agree with your conclusion that the textures in K7 output are less detailed, though the K7 output, on the other hand, looks smooter regarding noise. (I even opened the K20D output in Neat Image and attained somewhat smooter but still slightly better detailed image than the K7) But that initially neater look from the K7 is perhaps due to slight overexposure compared to the K20D. (When I want to crank the iso on my K10D to 3200 through an external software, I deliberately meter on darker objects or portion in the frame!) I should also say that, (relying on my office experience!) I find the WB of the K7 more successful. Another thing which grabbed my attention (assuming you shot these pictures with the same aperture value) is that though the K7 required a faster exposure time of 1/30 than that of the K20D which is 1/20 according to the exif, its output looks brighter as if the actual iso was somewhat higher than 3200(as in the case of earlier Canon dslrs)

Last edited by bahadir; Jul 12, 2009 at 8:52 AM.
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