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03-14-2018, 12:58 PM   #1
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HD DA 21mm Ltd Lens Not Sharp Enough, or Just My Focusing Error?

I recently shot a bunch of landscape backgrounds for a class project, and I used my recently bought Pentax KP and DA 21mm Limited lens for it. When looking at the images on my computer, they seemed somewhat soft for me, even images taken at apertures of f/11-16. Some landscapes where shot on tripod without SR, others were handheld with SR turned on. For pretty much all of the images shown, I focused on the horizon in the distance, aperture set f/11-16. When I zoom in, I feel like the images should be sharper than they appear. Is that just me, or is something wrong/off with my lens/KP body? This is the only lens I have, by the way (and the KP is my first ever Pentax camera).

Upon doing some research while creating this thread, I realized that the softness I perceive in my photos might just be user focusing error. If I set the aperture to f/11, and focus on the horizon line in the distance, does that mean everything past the horizon is in focus, and not things closer to the camera? So, I should instead focus somewhere in the middle of my scene for everything to be sharp, as in the hyperfocal distance? On one of the photos, instead of focusing on the horizon, I focused on a distant biker walking uphill. When I zoom in, he appears acceptably sharp. In another photo, of myself in my room, I set the focus to the window sill, at f/18. When zooming in, I feel like I'm a little soft while the window is sharp. But I do understand that this might be due to the 1/4" shutter speed on tripod, and I couldn't stay absolutely still for that duration, try as I might. However, I'd like to know for sure if my lens is fine and it's just my focusing methods that need improving. Do the images appear normal, based on the exif/exposure settings and data?

Here is the link to the original, unedited, RAW DNG images I've described, taken with the KP:
Update your browser to use Google Drive - Google Drive Help

03-14-2018, 01:14 PM   #2
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The general rule is that the depth of field will extend for one third in front of the point of focus and two thirds behind the point of focus. Depth of field being determined by the aperture used on the lens and the distance to the point of focus.

Landscape photographers juggle aperture and distance to point of focus to ensure that what they want to be in focus in a shot is actually in focus.

By focusing towards to horizon, that is further back into the photo, you will likely find much of your foreground and possibly middle ground is out of focus.

Regards

Chris
03-14-2018, 01:32 PM   #3
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Been there, was disappointed too. I think you're expecting too much from flat lighting and over-zooming when looking at your photos. Zoom in to 100% to check on details, but no more! (pixel peeping) Each pixel on your monitor will correspond to one pixel in your photo so no need to zoom any more.

The distant horizon in these photos is also subject to midday atmospheric haze, which is why landscape fans like to shoot at dawn when the light is low, the shadows crisp and long and details show clearly in the (sometimes) clearer morning air.

Your KP is a 24MP camera and can out-resolve my trusty K-7 and your Ltd can wipe the floor with my kit zoom, but a recent photo of mine looked to my eye like something shot with a K-1 because the lighting gave terrific detail and contrast on the subject. I'm not saying it's a wonderful photo, it just looks way sharper than anything I shot in the old days. It too was shot on a tripod.

https://i.imgur.com/2lCZU7q.jpg

Last edited by StiffLegged; 03-14-2018 at 01:43 PM.
03-14-2018, 02:01 PM - 1 Like   #4
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Some thoughts.
Wind blowing ? as in grasses and tree leaves moving.
Just cause you have f11, f16, f22, doesn't mean you should use them. Read here Diffraction Limited Photography: Pixel Size, Aperture and Airy Disks
As mentioned above,light was a little harsh.
Maybe process with dropping exposure a little, boost some contrast, sharpen

---------- Post added 03-14-18 at 04:01 PM ----------

Some thoughts.
Wind blowing ? as in grasses and tree leaves moving.
Just cause you have f11, f16, f22, doesn't mean you should use them. Read here Diffraction Limited Photography: Pixel Size, Aperture and Airy Disks
As mentioned above,light was a little harsh.
Maybe process with dropping exposure a little, boost some contrast, sharpen

03-14-2018, 02:32 PM   #5
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Try setting the camera to F8, focus on different objects at different distances. Use the tripod, use the remote if you have one with three second delay, if not use the 2 or 12 second delay, either of these methods automatically turn off SR, and should get rid of any shake from touching the camera on the tripod. Then do some of the same photos with manual focusing, using live view, focus peaking, and magnification. You may need to adjust the focus in camera for the lens. In your samples even the horizon doesn't really look in focus.so there could be a few things going on. It seems unlikely but you could have gotten a bad copy, but hopefully just technique and minor adjustments. I would suggest to shoot raw plus jpeg for testing, because your raw files would probably look better with a little processing, and for the tests you won't have to take time processing.
03-14-2018, 03:00 PM   #6
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I didn't pixel peep to see if they're pixel sharp, but immediately I see a lack of contrast due to the sunny mid day conditions. Lack of clouds also makes the pictures somewhat less interesting than they could be. There's no focal point in the pictures either, they seem like test pictures and not composed pictures. All of this makes them seem uninteresting. So sharpness isn't really your main concern.

You should be able to get results this sharp (not my picture): Autumn Park | Pentax K-3 DA 21mm 3.2 Limited Out of camera j? | Lepidoptorologic beauty* | Flickr <-- this was a straight out of camera jpeg at f/5.6 in a K-3 (also 24MP), so the borders aren't all that sharp, but the center sharpness is definitely there up to the very extreme borders, where it gets a bit soft likely because of field curvature.
03-14-2018, 05:43 PM   #7
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Don't get discouraged. Give it some time and learn the lens. I bought a used SMC DA21 and was a little disappointed at first. Turns out mine was back-focusing, I did a AF adjustment and spent some time with and it is one of my most favorite lenses. Plenty sharp. I hear the HD is a little better. And don't get too hung up on pixel peeping. Here some pics with my lens ...Search: 21mm | Flickr

And use this forum to learn...it is a tremendous resource.

03-14-2018, 08:14 PM   #8
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QuoteOriginally posted by 7.62lew Quote
Don't get discouraged. Give it some time and learn the lens. I bought a used SMC DA21 and was a little disappointed at first. Turns out mine was back-focusing, I did a AF adjustment and spent some time with and it is one of my most favorite lenses. Plenty sharp. I hear the HD is a little better. And don't get too hung up on pixel peeping. Here some pics with my lens ...Search: 21mm | Flickr

And use this forum to learn...it is a tremendous resource.
My HD 15mm Ltd is not as good as my SMC 15mm Ltd. My 21mm Ltd is not as good as my 20-40 Ltd. at 20mm..
03-15-2018, 02:07 AM   #9
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QuoteOriginally posted by CPLTarun Quote
I recently shot a bunch of landscape backgrounds for a class project, and I used my recently bought Pentax KP and DA 21mm Limited lens for it. When looking at the images on my computer, they seemed somewhat soft for me, even images taken at apertures of f/11-16. Some landscapes where shot on tripod without SR, others were handheld with SR turned on. For pretty much all of the images shown, I focused on the horizon in the distance, aperture set f/11-16. When I zoom in, I feel like the images should be sharper than they appear. Is that just me, or is something wrong/off with my lens/KP body? This is the only lens I have, by the way (and the KP is my first ever Pentax camera).

Upon doing some research while creating this thread, I realized that the softness I perceive in my photos might just be user focusing error. If I set the aperture to f/11, and focus on the horizon line in the distance, does that mean everything past the horizon is in focus, and not things closer to the camera? So, I should instead focus somewhere in the middle of my scene for everything to be sharp, as in the hyperfocal distance? On one of the photos, instead of focusing on the horizon, I focused on a distant biker walking uphill. When I zoom in, he appears acceptably sharp. In another photo, of myself in my room, I set the focus to the window sill, at f/18. When zooming in, I feel like I'm a little soft while the window is sharp. But I do understand that this might be due to the 1/4" shutter speed on tripod, and I couldn't stay absolutely still for that duration, try as I might. However, I'd like to know for sure if my lens is fine and it's just my focusing methods that need improving. Do the images appear normal, based on the exif/exposure settings and data?

Here is the link to the original, unedited, RAW DNG images I've described, taken with the KP:
Update your browser to use Google Drive - Google Drive Help
By f/11-16 you may be running into softness through diffraction. Also, for what it's worth, when I first got my DA21, it did front focus dreadfully. It was fixed finally by Pentax - this was years ago before micro-focus adjustment was available on the cameras.
03-15-2018, 11:59 AM   #10
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Thanks everyone, for your insightful responses. I really appreciate it.

I realize I have a lot to learn regarding the techniques and technicalities of photography. As some have suggested, I reviewed other photos I've taken, such as sunsets, at 100% and those images seem acceptably sharp, along with a few pictures of people. I'll also shoot different distance subjects at f/8 just to be sure, but I don't think I have a focusing problem with or bad copy of my lens. But, I do have to improve my focusing technique. So far, I'm loving the color rendition of the lens; I'm eager to master the lens so I can get the best image quality as well (after first improving composition of course).
03-15-2018, 01:14 PM   #11
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As shown in some test reviews, and in my own experience over the years with Pentax DSLR models, the KP included, be sure to go to the Custom Image menus and adjust sharpening to Fine Sharpening, both in the normal, default "Bright" and in the "Natural" categories. When in these menus, the 4 buttons around the "ok" button serve for navigation and for level adjustments. Fine Sharpening is implemented via the rear thumb dial.

Note that the sharpening level is up by one notch in the "Bright" category as default, but not in the "Natural" category- so you could increase level by one notch there also, in addition to engaging Fine Sharpening, which brings out better detail in images. After adjusting, then be sure the camera is put back to "Bright" since it is the standard default for overall use.

Last edited by mikesbike; 03-15-2018 at 01:55 PM.
03-15-2018, 01:34 PM - 3 Likes   #12
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QuoteOriginally posted by CPLTarun Quote
Here is the link to the original, unedited, RAW DNG images I've described, taken with the KP:
These images look misfocused to me. Perhaps focused past infinity? Something of that order. In any case, I can get sharper images out of my KP/DA 21 combo:



03-15-2018, 08:02 PM   #13
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QuoteOriginally posted by northcoastgreg Quote
These images look misfocused to me. Perhaps focused past infinity? Something of that order. In any case, I can get sharper images out of my KP/DA 21 combo:


Wow, they are wonderful shots, Greg. Where did you take these? Did you use f/8 aperture?
03-16-2018, 12:43 PM   #14
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I found using f6,3 to f7,1 was the sweet spot on my da21. Try these values and see how you go. I wouldn’t push it further than f9 for 99% of my shots.


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03-16-2018, 08:24 PM   #15
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QuoteOriginally posted by CPLTarun Quote
Wow, they are wonderful shots, Greg. Where did you take these? Did you use f/8 aperture?
These are shot at f8. First shot is Trillium Falls in Redwood NP. Second shot is from Sequoia Park in Eureka, CA. Both are manually focused.
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