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10-18-2014, 10:18 AM   #1
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K5 sharpness?

Hello,

I am new to this forum. I recently bought my first DSLR and I chose the K-5. I've heard repeatedly that it was a wise choice. The two lenses I own, are the DA 21mm and the DA 70mm (limited, green rings). These are all bought at second-hand. The body should have been looked at by Pentax.

Now, I am actually quite fast at catching up the principles and technical possibilities of the digital camera. Yet, the past couple of weeks I shot only 1, or maybe 2 truely 'sharp' pictures.

I am quite young so I have a relatively steady hand .

Yet I was thinking that none of my pictures were ultra sharp because of movement somehow. So I invested in a tripod, a relatively good one. Now I have tested the camera indoors (ISO 3200), yet again none were really sharp. Agreed, some were moving objects but the shutter speed was high enough.

(I know that every photographer shoots a lot of pictures and maybe 1 on 20 or 30 he truely likes)

I've read from other experiences that the combination I have shouldn't have that many problems with shooting in less light.


I still am a beginner, so am I doing something wrong? Or could there be a technical issue (I'm thinking with the focus or something)?


And how do I attach pictures here with a lower format, so when you click on them you can see it in original format?

Thanks for reading

10-18-2014, 10:37 AM   #2
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You might need to adjust the AF, which is pretty painless. I'm sure somewhere in the tutorials here one must deal with the topic. The K-5 can adjust all lenses the same amount and/or adjust for a specific lens, so it's rare that this cannot correct focus issues unless the lens needs service.
10-18-2014, 10:45 AM   #3
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Will this help?
How to Quickly Test Your DSLR for Autofocus Issues



And I know sounds like -kind of- a stupid question above. But I really have the feeling I'm doing things fine. But the results don't exceed the quality of my snapshots by an old compact camera or pictures by other beginners.

Composition, lighting,.. are things you can discuss. It can be done wrong. But just taking a picture (i've tried it in auto, Av, Sv, P, USER, etc...) very steady and on the computer it just isn't quite that.
10-18-2014, 10:47 AM   #4
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Ii hard to tell what you are doing wrong without seeing some examples. Both the DA21 and the DA70 should be pretty sharp nearly all the time.

10-18-2014, 10:50 AM - 1 Like   #5
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There are a number of things that can make an image sharp or not.
In no particular order:

1. focus accuracy (deal with it perfecting your manual focus skills, adjusting focus as jimr-pdx suggested for greater AF precision, understand how AF points work, how big they are which are cross-type and which are not, if any)
2. shutter speed/motion blur (suggested shutter speed is 1/(focal lenght*crop factor): that is, with a 50mm - 75mm equivalent FoV in 35mm format - it is 1/75sec, so 1/125 rounded up at the next speed)
3. subject movement (if you shoot a fast-moving subject, you have to adapt your shutter speed accordingly, and eventually use techniques such as pan)
4. ISO (ISO3200 is not the best speed if you want sharp pictures, as you have a fair bit of NR going on... if you are shooting from a tripod you can take advantage of it and shoot at ISO100. Use a 2s timer - that also disables SR which is a good thing on a tripod - or a remote)
5. aperture (most lenses are not too much sharp wide open, and if you stop down too much you get diffraction, which also softens the images. Sweet spot is generally between f/5.6 and f/11, try f/8 and be done with it ;-) )
6. Lens characteristics (if a lens is only sharp in the center, especially wide open, and your subject is near the edges, and you have OOF in the center of the image, there will be nothing sharp in that picture)

There's more to photography than pressing the trigger ;-)
10-18-2014, 11:22 AM   #6
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Thanks for summarizing that out. Some things I already knew. But the remarks about focus and 'OOF' are kind of new to me.


Most of my pictures are with wide aperture (f/ 2.4, f/3.2): objects, people and my pet have been my primary test objects




Now I took some mediocre pictures, but most of them are just for trying things out (bracketing, etc.). So the following pictures are quite bad. I just want you to look at the sharpness. None of them are sharpened afterwards.


There are a lot of test pictures on this forum (K-5), there is only one in terms of sharpness that I made and is similar to it.




This one:


http://oi58.tinypic.com/doufbn.jpg


EXIF: 1/60, f/ 2.4, ISO 1100, 70 mm


This one (in terms of sharpness) wasn't bad either:


http://oi58.tinypic.com/24cwjer.jpg


EXIF: 1/125, f2.4, ISO 200

---------- Post added 10-18-14 at 08:30 PM ----------

I couldn't edit, so..


Here is an example of how a picture should be better I think (and most of my pictures are this kind of sharp, in any light setting)


http://oi62.tinypic.com/9bhhub.jpg


Exif: 1/100, f/11, ISO 200

---------- Post added 10-18-14 at 08:32 PM ----------

QuoteOriginally posted by Nephus Quote
Thanks for summarizing that out. Some things I already knew. But the remarks about focus and 'OOF' are kind of new to me.


Most of my pictures are with wide aperture (f/ 2.4, f/3.2): objects, people and my pet have been my primary test objects




Now I took some mediocre pictures, but most of them are just for trying things out (bracketing, etc.). So the following pictures are quite bad. I just want you to look at the sharpness. None of them are sharpened afterwards.


There are a lot of test pictures on this forum (K-5), there is only one in terms of sharpness that I made and is similar to it.




This one:


http://oi58.tinypic.com/doufbn.jpg


EXIF: 1/60, f/ 2.4, ISO 1100, 70 mm


This one (in terms of sharpness) wasn't bad either:


http://oi58.tinypic.com/24cwjer.jpg


EXIF: 1/125, f2.4, ISO 200

---------- Post added 10-18-14 at 08:30 PM ----------

I couldn't edit, so..


Here is an example of how a picture should be better I think (and most of my pictures are this kind of sharp, in any light setting)


http://oi62.tinypic.com/9bhhub.jpg


Exif: 1/100, f/11, ISO 200
Ok bad example because the focus isn't on the horse now. But I can give a lot of pictures where the focus is on the subject and it is as sharp as that horse is.
10-18-2014, 11:32 AM - 3 Likes   #7
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QuoteOriginally posted by Nephus Quote
Now, I am actually quite fast at catching up the principles and technical possibilities of the digital camera. Yet, the past couple of weeks I shot only 1, or maybe 2 truely 'sharp' pictures.
Hey there. Sharp photos are actually the pinnacle of the technical side of photography. It is hard to get truly sharp photos consistently. I can tell you that after some years of usage you will have a much higher number of sharp photos. When I look back at the photos I took in my first year or two, they all seem out of focus, shaken, blurry to me now. Here are some pointers, but it really comes down to experience and practice.
a) stance. This is very important. How you hold the camera, how you position your body. Do you press your camera to your face, do you tuck your elbows in, do you use the left hand as a base and right hand only to press buttons, etc. Even if you are young, that doesn't mean your hands are steady - in fact, you might be energetic and impatient, making photos less sharp. If you take just a couple extra seconds per photo to position yourself and hold the camera steady, the photos will be sharper
b) button press. A lot of people press the shutter button FAST and HARD, but this is not really required. It is better to guide the button in slowly, so the camera doesn't get shaken and tilted. The button pressing hand should have almost no pressure on the camera body, only on the buttons.
c) technical settings. First is aperture. Most lenses are sharpest one or two stops down from wide open. I think the K-5 has a special P mode that chooses the sharpest aperture for your specific lens. Each aperture has its own resolution, wide open is usually not perfect, and once you go over around f10, diffraction sets in. At f16 it is very noticeable, and at f22 even more. The second part of aperture is DoF! People often blame a lens for being soft, but actually it is just the DoF that is so shallow, that everything except a 2mm wide patch is OoF. Then there is shutter speed, which needs to be fast enough for the lens' field of view. The rule is generally 1/(focal length), but to be safe on crop sensor, people often use 1/2*(focal length). But shake reduction and steady hands can help with this. Then there is ISO, which is actually noise, but it can make a photo seem softer. The lowest ISO should be used, but it depends on how much light you have to work with.
d) Jpeg mode, digital sharpening. The crazy-sharp photos you see online are always sharpened digitally. Post processing is important, there are many sharpening settings, programs and even different methods that you can use if you shoot raw. If you shoot jpeg, the camera still lets you choose between two types of sharpening (regular and "fine") and the strength. To do this, press Info, choose jpeg mode (bright, landscape, vibrant, film reversal,...) and press Info again. Now you can add saturation, sharpening, contrast. Feel free to add some, or to toggle between regular and fine sharpening. There were debates about which one is better. Ultimately, they are just "different"

To really test a lens' sharpness, you need a tripod. In good daylight, place the camera on tripod. Select 2 sec timer (and remote shutter, if you have a remote). 2sec timer is great because it includes mirror lockup, which means there is less blur due to mirror slap. Select Av mode on the mode dial and choose the lowest ISO (80 on K-5) and the lowest f-number your lens allows. Select manual focus, and put the lens' focus to somewhere near minimum, but not at total minimum. Now grab a magazine or newspaper and place it at 45 degree into your focus area. If your lens has distance scales, you can use a measuring tape (beware, distance scales measure from the sensor to the subject, not from the front of the lens to the subject). Make sure there is no wind and that the tripod is solid. Do not walk while the camera is taking photos. Now let the camera use the timer and take the photo. Take photo to computer and zoom in to 100% (and not above!) The photo should have a nice patch that is in focus, this is where the letters will be sharp, and you will even see the texture of the paper. Outside of the DoF will be blur/bokeh. The DoF is probably not a flat, horizontal line, but slightly bent and of varying thickness in the centre and on edges. Study the lens to figure out its characteristics. If the DoF is really odd, like sideways or something, the lens might have a defect.
Now do the same thing, but in Av mode select the "best aperture" of your lens (you can look at online reviews or use the built in K-5 function). If the lens is soft at this aperture, if the photo has no clarity, then the lens might have a defect. At best aperture, any modern Pentax lens should be decent, unless it has a defect. Of course, DA L 18-55mm will not be in the same league as DA HD 35mm limited macro.
Next try the same process but with f8. This is usually the upper limit, with the biggest DoF before sharpness starts to drop due to diffraction. If the lens' DoF is not wider than it was in the previous photos, if the photo has odd optical aberrations, the lens might have a defect.

This method is great, because it tries to isolate gear from problems like atmospheric haze, poor light, user error, etc. It measures only the gear's performance.

Oh, and zoom lenses perform differently at different focal lengths. Some are better at one end than the other, some are best in the middle (DA 18-55mm is best around 35mm, if I remember right)
10-18-2014, 11:34 AM   #8
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QuoteOriginally posted by Nephus Quote
Thanks for summarizing that out. Some things I already knew. But the remarks about focus and 'OOF' are kind of new to me.
OOF is shorthand for Out Of Focus.
What I meant is that the sharpest part of the lens is the center, especially wide open, so be careful where you put your subject and where the (out of focus) background...

First one is a little slow, 70mm => 105mm equiv FoV, 1/125sec or faster is suggested, even though shake reduction (SR) can mitigate that.
There's quite a bit of purple fringing which derives from 1. the lighting conditions and 2. shooting wide open

Second one, I kinda like it. Composition is good & pleasing, colors are fantastic, sharpness cannot be judged at that resolution (even clicking on "show raw image" displays a 1MP or so image, not full resolution)

10-18-2014, 11:48 AM   #9
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Thank you for al this advice.


* I think I may have found a big problem that plays part in a lot of pictures I took. Which is having the aperture wide open, being close to the object, but not using the middle focus point. I tend to use 'SEL' and select another focuspoint to have a better composition.
I'll try to hold the 'push button' and recompose that way.


* I always try to shoot RAW, but I always forget to go into settings and change it there (so I wouldn't have to push the RAW button each time and I could use that button for something else). Most of my pictures are JPEG for now.


* I do shoot steady I think. I think I have the correct stance.


* To summarize the rest. I bought Scott Kelby's manual for beginners. So the most basic stuff I know. I also read the internet, yes.


And thank you Na Horuk, I will take that test tomorrow


And as I said above I bought a tripod. Only used it inside at ISO 3200. I know the disadvantage of a high ISO, but does it affect the 'sharpness' too? Then there wouldn't be sharp concert photos to be found for example. And I used the 2 sec timer.
10-18-2014, 11:55 AM   #10
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Nephus,

Lenses tend to sharpen up after they are stopped down a bit. Close your aperture down to f/4 to f/6.3 for general usage. You can check detailed online lens reviews and you will see sharpness peak for most lenses in that range before falling off again. That doesn't mean you shouldn't use a lens at f/8. Just understand that you are giving up a little bit of actual sharpness for increased depth of field which is perceived sharpness.

Also, don't give up on wide open apertures. They are great for portraits. Focus on the eyes, recompose, and fire. You will have a beautiful and dreamy rendering.
10-18-2014, 11:59 AM   #11
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QuoteOriginally posted by Nephus Quote
Thank you for al this advice.


* I think I may have found a big problem that plays part in a lot of pictures I took. Which is having the aperture wide open, being close to the object, but not using the middle focus point. I tend to use 'SEL' and select another focuspoint to have a better composition.
I'll try to hold the 'push button' and recompose that way.
That depends. When you recompose you move your camera and risk changing the part which is in focus, so you need to think about the method you intend to use and know its strenghts and weaknesses...


QuoteOriginally posted by Nephus Quote
* I always try to shoot RAW, but I always forget to go into settings and change it there (so I wouldn't have to push the RAW button each time and I could use that button for something else). Most of my pictures are JPEG for now.
My advice is to just shoot RAW, so just leave it there.
This way you always get an integrated jpeg preview (that you can also extract from the raw file if needed) and you can process your pictures for maximum quality. Takes two clicks if you don't have time, you get even better results if you do.


QuoteOriginally posted by Nephus Quote
* I do shoot steady I think. I think I have the correct stance.


* To summarize the rest. I bought Scott Kelby's manual for beginners. So the most basic stuff I know. I also read the internet, yes.


And thank you Na Horuk, I will take that test tomorrow


And as I said above I bought a tripod. Only used it inside at ISO 3200. I know the disadvantage of a high ISO, but does it affect the 'sharpness' too? Then there wouldn't be sharp concert photos to be found for example. And I used the 2 sec timer.
Yes of course: since you get more noise, you also need more noise reduction, and that also affects fine detail.
"Sharpness" is a relative concept, and has to do with things such as resolution, size and viewing distance.
A soft 16MP picture can be downsized or simply viewed on a fullHD monitor (about 2MP) and can appear sharp. It's when you zoom in (or you crop) that the difference becomes apparent.
That's why many people say that a 6MP camera is more than good enough if you only post to facebook/flickr/twitter: you'll be posting 1MP images so there's no need to have a 16MP camera!
10-18-2014, 12:00 PM   #12
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QuoteOriginally posted by 6BQ5 Quote
Nephus,

Lenses tend to sharpen up after they are stopped down a bit. Close your aperture down to f/4 to f/6.3 for general usage. You can check detailed online lens reviews and you will see sharpness peak for most lenses in that range before falling off again. That doesn't mean you shouldn't use a lens at f/8. Just understand that you are giving up a little bit of actual sharpness for increased depth of field which is perceived sharpness.

Also, don't give up on wide open apertures. They are great for portraits. Focus on the eyes, recompose, and fire. You will have a beautiful and dreamy rendering.

That is exactly what I do. I try to open the aperture for portraits and close objects, so you can create a nice "bokeh". For other things, more at distance I usely try f/5.6.


I'll give it another go tomorrow. But when I zoom in, everyting always seems a bit OOF ( ).


Probably in a year or two from now, I will look back upon this moment and think of myself: "What were you thinking?"
10-18-2014, 12:02 PM   #13
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All I know is may have solved a problem I've been having. Thanks for all the information! ( Focal length and shutter speed)
10-18-2014, 12:25 PM   #14
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QuoteOriginally posted by Nephus Quote
Probably in a year or two from now, I will look back upon this moment and think of myself: "What were you thinking?"
When I bought my first DSLR (k-x) I looked at pictures taken and thought I had made a big mistake. Images with my old bridge camera were much better. Seriously considered returning the k-x. But I learned and got better. A DSLR gives you the potential to take far better images, it does not guarantee it. You have to develop all of the skills to make the image. On a point & shoot mostly it is hard to get it wrong but also hard to get it great.

Since you seem to like wide open aperture shots take a look here and study just how big the depth of focus (DOF) is when you have a lens wide open: Online Depth of Field Calculator Those photos can be very creative and striking but you might want to start out at something a little less demanding until you have mastered the camera. Getting an image in focus with a 1/4" DOF is not easy without practice.
10-18-2014, 12:33 PM   #15
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QuoteOriginally posted by Nephus Quote
I'll give it another go tomorrow. But when I zoom in, everyting always seems a bit OOF ( ).
Something to keep in mind- it's pretty demanding to view a 16mp image at 100% magnification (if that's what you're doing). It depends on the pixel density of your viewing device, but on my monitor that would be similar to printing an image from a k5 at 3' by 4.5' and then viewing it from a little over 2' away. While a 100% view is great for the critical eye, never forget what the end output of your image is.

As mentioned, down sampling to websize is more forgiving. So if you're comparing the sharpness of web sized images from others with the sharpness of your own images that you're able to view at 100%...well that's just not fair to you.

For the sharpest possible results:

-use the tripod
-use low iso, 80 or 100.
-stop down a little, f/4 or f/5.6 or f/8
-use mirror lock up with a remote
-shoot something that's not moving (even a little breeze can hurt)
-check the focus with live-view, or better check it on a computer without moving the camera or scene you're shooting and re-shoot if the focus was off
-shoot in raw and do your own sharpening in post production

Do this with a few scenes and lens choices and you can get an idea of the gold standard your equipment can achieve. Real-world shooting will often require you to compromise on some or all of the above. Experience and practice will help you learn which of the variables you can compromise on and still get a sharpness you're happy with.

Good luck and above all, have fun!
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