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10-11-2012, 01:36 PM - 1 Like   #1
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Bad image quality?

Hi everyone! I bought a new Pentax k-r (18-55mm kit) in August and I am a bit disappointed.

I think the photos I take are all bad. Maybe not in the idea sense, but the quality is really not what I expected. I will post some examples and explain better.

So, I think the edges of the objects are kind of blurry or smudged, definitely not sharp. I am not that new to photography thing, I have been taking photos for about 6 years, but using a DSLR for only a couple of months. I got to try a friend's Nikon D3100 and I was like "wow, I want one too!". I had picked out the Pentax one I have right now, a long time ago, though. For some reason I definitely had to have a Pentax, I don't know why, I had been using a Canon and an Olympus so far.
Anyways, I have read the manual, which helped me understand a few things better. Also, the friend with that Nikon took a photography course and got this workbook which also explained some techinques and all that stuff, so I read that too. I began to think that it's all me, like I don't know how to take photos and stuff like that. I still do think it's not only the camera, it is also the photographer. But, I don't really know what else to do.

So, here I am, asking for advice... Maybe I need to change certain settings. Or maybe I'm just being delusional and everything is normal.

And sorry if this has been posted before, I'm not trying to be lazy, I have searched for a solution, but I did not find the answer.

The photos:

umm, not the best photo, the lightning is real bad...

zoomed in a bit





while this one looks okay to me:


then there are these (not taken by me, but with my camera):


this one is like especially weird. the eyes and lips are like smudgy, while the hair seems fine and the background is blurry as expected.





I think these samples will do...

You might think why do I zoom in the photos, but it's a habit of mine, and if it doesn't look fine to me zoomed in, I don't like it. And that is the reason I'm posting here, all my photos are like that. I used to love taking photos, then it started to fade away. I bought a new camera, hoped it would bring back the inspiration and everything and it did, but this is definitely not helping.

I don't know what I'm doing wrong here, so a little help maybe?

Helena


Last edited by hollywoodhr; 06-14-2013 at 01:17 PM.
10-11-2012, 01:49 PM   #2
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search the forums about front/back focusing issues. From the last pic, it seems like your camera is backfocusing. You can see the hair in the front of her face is not as sharp as the strands off to the side in the back. Don't worry, it's a common issue on my camera and lenses. It's easily fixed via the fine focus adjustment in your camera.
10-11-2012, 01:52 PM - 1 Like   #3
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Generally image issues are the lens, rarely the sensor. You can test your 18-55 by setting your k-r on a tripod, set it to 30mm, F8, and take a picture. It should be sharp enough by any standard.

What I believe is happening here is a few things:

1) Your focus isn't spot on. Perhaps the camera is choosing an odd focus point.
2) You are using your lens at its weakest apertures for most of these shots. The first tree shot is at F3.5, the forest path is at F4, and your portraits are at F5.6 @ 55mm. So they aren't going to be as sharp, and combined with slight miss-focus will make it look very soft.
3) You are shooting a bit slow for some of these shots: The tree shot is at 1/30s (18mm) - normally this is ok, but you may not be used to holding the camera correctly, so it can introduce a little motion blur. The portrait was shot at 1/40s @ 55mm, and that's really too slow.

Each of these can be fixed - use center focus, shoot faster than the focal length (1/100s is good for a beginner until they get steady hands), and try to stop down 1 stop.
10-11-2012, 02:01 PM   #4
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To get sharp images, your camera must be focusing properly, and you must have no camera movement during exposure.

Camera movement is the easy one--make sure your shutter speed is sufficiently fast, or use a tripod.

Focusing is the more problematic.

Auto focus: In order for auto focus to be precise, the distance from the lens to sensor must be equal to the distance of the lens to autofocus sensor. On some models you can adjust that yourself, otherwise you need to send your body plus lens into the service centre.

Manual focus: The distance from lens to sensor must equal the distance from lens to focus screen.

This diagram may help:
Focusing Screen--How to adjust focusing screen--

L1 must equal L2 must equal L3

You can adjust the focus screen position with shims. Search these forums for more info.

Making these adjustments is well worth the time.

Also, as a rule, most lenses show their best sharpness a couple stops down from wide open.

Good luck!

10-11-2012, 02:05 PM   #5
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I think, before we question if it's back or front focusing, he should let us know what focus mode he is using (single point, 5 point auto, 11 point auto).

I'm wildly guessing 5 or 11 point auto, and the camera just chose the wrong focus point.
10-11-2012, 02:12 PM   #6
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I'd say the problem is bad technique, combined with poor understanding of camera limitations. Honestly, I wouldn't bother very much if the pictures aren't tack sharp at 100% crops. People rarely look at others' pictures more than a split second anyway. The picture with the road lacks depth of field, in my opinion (but I still like it). The portraits look shaken and/or overexposed, and the tree trunk is simply bad light. So you will find, if you haven't already, that good light comes in small quantities. So ideal photography conditions (say 100 ISO for good detail, f/8 aperture for depth of field and 1/1000 exposure time to avoid blur) can very rarely be achieved. Depending on your will to get a good picture, you can either compromise on one (or all 3) of these factors, or carry a tripod and lengthen the exposure as necessary.
10-11-2012, 02:16 PM   #7
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I tried that tripod thing, well except that I don't have one, I took the photo on the table:



I had previously (the first day I bought the camera) taken this photo, on a table too, which is not bad imo:



As for the focus mode... I think this is what you meant and this is my setting, I don't know what it is. I changed it to this yesterday and left it that way, the photos of the tree and the forest are taken with these settings...

10-11-2012, 02:53 PM   #8
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That third one does look like "Select Point" - I assume the center one is pink, and the rest grey?

The Blistex picture looks pretty good (shot at ISO 100 and F8) - were you satisfied with that?

It's important to learn the quirks of how your camera's AF handles. Generally your kit lens should be pretty ok with AF, and until you learn a lot more about how your camera works, worrying about back and front focusing (unless it's a huge amount) isn't going to solve problems for you. If the Blistex shot is sharp enough for you, then for your subsequent pictures do this:

1) Don't shoot below 1/100s until you are used to handling the camera.
2) Stop down to F5.6 for most shots.
3) Aim for what you want in focus, and recompose. Make sure the object you are aiming at is very contrasty (for example, in the lady, aim for her eyes). Subjects that aren't very contrasty can confuse your autofocus - the tree is a dark brown and the ladder is brown. The camera might not focus on the ladder automatically. The forest trail is a mash of subjects. The camera may have trouble focusing at the distance subjects.

Again - The AF on the camera is different from brand to brand, and they all have their own quirks. Taking more and more pictures will allow you to use the camera properly.

10-11-2012, 03:06 PM   #9
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Thanks JinDesu!

It is the select point exactly, that I am using right now. But I don't understand two things. The "AF Mode" and "AF Metering". In AF Mode I have AF.A, AF.S and AF.C. I tried all of them, and I don't like AF.C for sure. but what are AF.A and AF.S? i currently have set it on AF.S. And what is AF Metering?

a photo of my setting, just in case

I am indeed satisfied with that Blistex photo. I also took photos of some other random items, and they looked good too, in my opinion.

I will try to take some photos tomorrow, with the knowledge I got from all of you who commented, thank you! I'll see what comes out from that.
10-11-2012, 03:12 PM   #10
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Based on the last two pictures I doubt there is anything wrong with camera or lens, those look pretty good. Both taken @ f/8 which is a better spot for that lens. I think the problem is technique and though everyone here can give you advice you really need to learn photography and practice to understand. There is a learning curve, and it involves study and taking a lot of pictures. I average 10,000 shutter activations a year and that is not all that many. Each of those is an opportunity to learn why the image was good or bad. At first it will seem like nothing is going right because there are so many variables. You need to learn the camera one aspect at a time. Aperture, shutter speed and ISO all need to be balanced, try playing with one at a time until you understand what each does. Take lots of pictures and study each one.

  • The aperture on your lens can go from f/3.5 to f/16 I think. The wide open apertures (f/5.6 and wider) will make softer images than when you set the lens to the middle (f/6.7, f/8, f/11). Sometimes you have to use those apertures anyway to get the shot but understand that it will not be the best. This is often called the 'sweet spot' of the lens and though it varies it is usually close to f/8. More expensive lenses have a bigger 'sweet spot', really expensive lenses are sharp all the way open. The kit lens is pretty good if you know it's limits but it is not a $1,000 lens.

  • Try using single spot focus, this allows you to know exactly where the camera is focusing. The mode you used has 11 focus spots and is user selectable as to which one is going to be used and on the k-x there is no feedback to which one is selected. It is possible you moved the focus point to something off to the side. So in your images of the girl it could easily have locked onto her hair and with your large aperture (which causes narrow depth of focus) you would have the hair in focus and her eyes and lips out of focus.
  • Pentax shake reduction takes a few seconds to stabilize and lock on. This is indicated by the 'green hand' icon in the view finder. Do not shoot until the 'green hand' shows up. I think rushing the shot causes more soft images than just about anything else. Especially with people not familiar with how SR works with Pentax.
  • The tree pictures: lousy lighting, a little underexposed, shot wide open. Just not a situation that lends itself to good images.

  • This is a DSLR, not a point and shoot. So you really do have to learn photography if you want to get better. This takes time and practice. Learning how to hold a camera sounds silly, but it is very important. Proper technique in holding, proper breathing, the proper way to squeeze the shutter button all play a part. A good shooter can hand hold at 1/30th, someone just picking up the camera may take the same shot @ 1/250th and still get a blurry shot.
10-11-2012, 07:30 PM - 1 Like   #11
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QuoteOriginally posted by hollywoodhr Quote
Thanks JinDesu!

It is the select point exactly, that I am using right now. But I don't understand two things. The "AF Mode" and "AF Metering". In AF Mode I have AF.A, AF.S and AF.C. I tried all of them, and I don't like AF.C for sure. but what are AF.A and AF.S? i currently have set it on AF.S. And what is AF Metering?

a photo of my setting, just in case

I am indeed satisfied with that Blistex photo. I also took photos of some other random items, and they looked good too, in my opinion.

I will try to take some photos tomorrow, with the knowledge I got from all of you who commented, thank you! I'll see what comes out from that.
AF.S is a combination of AF.A and AF.C.

AF.A - Waits until the shot is in focus to allow the shot to be taken. Good for most things.
AF.C - Allows the shot to be taken even if the focus hasn't locked yet. Good for fast sports where the focus won't change much.
AF.S - Selects the two based on subject characteristics. See your manual for more info.

AE metering:
Top option - Area metering. Meters the whole scene and tries to set exposure for the middle (or slightly underexposed).
Second option - Central area metering. Meters the center area (middle 50%) of your scene and exposes for that.
Bottom option - Spot metering. Meters the middle of your scene.

I use spot metering and point at the bright and dark spots of my scene to determine the exact exposure I want. Most people use central area and full area metering as it saves time and is generally reliable.
10-11-2012, 10:33 PM   #12
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I don't see the pictures he posted. -.- there's probably something wrong with my browser
10-12-2012, 04:19 AM   #13
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Okay, so I went out to take some photos today, and tried to use the advice I was given here. I did not take a photo that was under 1/100, tried to remain in that f8 range, though I did even use f29 at some point..... I even tried setting ISO lower/higher. I use the M mode. Anyways, I don't know, I tried to follow what I was told and here are the results.

These are only samples, I took like 20 photos of each scene and they all looked kinda the same, maybe some was lighter, some darker.












Nothing's changed.

While I took this photo of myself and it looks fine.



I just wanted to give some feedback. I understand I don't become a good photographer overnight and it takes time to get used to my camera and know exactly what works in which way, you know.
10-12-2012, 04:28 AM   #14
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Don't go beyond F13 if you are going to look at the pictures super closely. Just as wide open is soft, beyond F13 you will see diffraction softening the picture.

The first shot is actually pretty reasonable for the kit lens. The third shot seems quite muddy, and I suspect is the focus (as the foreground seems to be in focus). Are you shooting RAW and processing after? Or are you shooting JPEG straight from the camera?
10-12-2012, 04:32 AM   #15
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I'm shooting JPEG
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