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03-25-2014, 05:02 PM   #1
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K-50 focusing in distance -- capabilities?

Hi, I'm new to DSLR (and this forum), but have enjoyed point-and-shoot photography for about 40 years. I just bought the K-50 and am hoping it will be the right camera for me. In addition to the 18-55mm kit lens, it came with a 50-200mm. I've had it a few weeks and am still studying the manual.

For now, I'm trying to focus on small objects (like an animal or a tree) in the distance, maybe 100-200 feet or more. I don't expect a lot from the lens that came with the camera, but I'm want to figure out what settings to use to get the best image and to see what the camera can do in the distance. (I would be cropping the image close to the subject of interest.) I've tried different settings for the autofocus, but haven't tried manual focusing yet. I just started experimenting with the settings for the focusing point (the user "select" option) and Aperture Priority mode. I take other sorts of photos, but my current concern is what it can do at longer distances. I'm not going to invest in a telephoto lens until I know what it can do with what I have. So far, it doesn't seem like I'm getting much better images of distant subjects than with my point-and-shoot 8MP 6X zoom camera.

My two basic questions are about which sort of settings to try for distance shooting, and what I can expect with my 50-200mm lens.

Thanks!

EJ

03-25-2014, 06:50 PM - 1 Like   #2
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Welcome to the forum, and the vast new world of DSLR photography.

I have my K-50 set to the center focus point, so I always know what it will focus on.
However, remember that there is a fairly large area where the camera will look for focus,
basically one-ninth of the rectangle you see in the middle third of the viewfinder.

The PDAF or "phase-detect autofocus" when you look through the viewfinder is fast,
but may not always be accurate, depending on the lens.
The CDAF or "contrast-detect autofocus" when you use live view
tends to be a little slower, but is more accurate.

The K-50 has 16 MP, so especially with the kit lenses you are using,
cropping to half the frame, or 8MP, is unlikely to give you
much better quality than what you can get from a good long-zoom point and shoot camera.

If you learn how to do manual focus, which is quite easy with the focus peaking in live view,
you can upgrade to a cheap old manual telephoto lens like the
SMC Pentax-M 200mm F4 Reviews - M Prime Lenses - Pentax Lens Reviews & Lens Database
which is very good for distant subjects.

Another trick is to use post-processing, for example with the Silkypix program that comes with the K-50,
to improve your images. I prefer to shoot in RAW + JPEG,
so I can quickly see what the JPEG looks like,
but can then process the RAW file for the best results.
03-25-2014, 07:09 PM - 1 Like   #3
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QuoteOriginally posted by lytrytyr Quote

Another trick is to use post-processing, for example with the Silkypix program that comes with the K-50,
to improve your images. I prefer to shoot in RAW + JPEG,
so I can quickly see what the JPEG looks like,
but can then process the RAW file for the best results.
It can't fix focusing problems, lytrytyr.

---------- Post added 03-26-14 at 02:19 AM ----------

QuoteOriginally posted by E-Joan Quote
I've tried different settings for the autofocus, but haven't tried manual focusing yet. I just started experimenting with the settings for the focusing point (the user "select" option) and Aperture Priority mode. I take other sorts of photos, but my current concern is what it can do at longer distances. I'm not going to invest in a telephoto lens until I know what it can do with what I have. So far, it doesn't seem like I'm getting much better images of distant subjects than with my point-and-shoot 8MP 6X zoom camera.
The 50-200 is lowest on the rungs of Pentax long zooms, EJ, but let's sort out some things first.

The longer the focal length, the worse your shaking hands are going to blur the final image.

Here's what you need to do.

Mount on a tripod. Set 2 second delay. Set centre focus. Take shots of a well-lit test object in the distance, practising both AF and MF. As you go, change aperture from f4 to f11.

These will be baseline images you can analyze afterwards.
03-25-2014, 07:47 PM - 1 Like   #4
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Anything past ~30' will be focused at infinity... You are more than likely running into the limitation of your lens. My 50-200 isn't bad at all but it is far from amazing when shooting at a distance. If you are looking for sharp and detailed pictures at that kind of range, you need a lot more than 200mm. And as it was suggested, a Prime would serve you better.

My rule of thumb regarding this is, take a look at the distance scale on your lens... It'll go from 0.1' to 30' (for example) and then you will get the infinity symbol... What that means is anything further than 30' will only be "acceptably" sharp. Some lens do it better than others, the 50-200 isn't doing it extremely well.

Most zoom lenses tend to fall apart at the long end. And since the 50-200 is a fairly slow zoom the sweet spot between a too shallow DoF and the onset of diffraction is very small. Also even if the shake reduction is very good on a K50, on a telephoto lens it has it's limitation. Try to shoot with a tripod and using the timer, this should improve the sharpness a bit. Using a polarizer could also help with contrast. Using the lens hood will also help. And also, try to shoot at lower ISO, noise might spoil your shot, especially if you've got noise reduction ON since it soften the image.

One last thing. There is no doubt that your K50 is a much more capable camera than your P&S, your lenses on the other hand may actually be worst than the P&S. Some P&S do come with amazing optics, rent or borrow a DA*300 and see if it is better. You can also consider some M42 lenses with adapter, you can get amazing ones for almost nothing.


Last edited by fgaudet; 03-25-2014 at 07:54 PM.
03-25-2014, 07:48 PM   #5
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QuoteOriginally posted by clackers Quote
It can't fix focusing problems, lytrytyr.
OP has the problem that the cropped K-50 images are little better than those from the P&S.
PP, especially on RAW files, can help improve the K-50 images.
And yes, a little sharpening can most certainly mitigate a focusing problem.

---------- Post added 03-25-14 at 09:52 PM ----------

QuoteOriginally posted by fgaudet Quote
take a look at the distance scale on your lens... It'll go from 0.1' to 30' (for example) and then you will get the infinity symbol... What that means is anything further than 30' will only be "acceptably" sharp.
The markings on the focus scale do not govern a lens's IQ at infinity.
That is determined by the optical formula of the lens.

---------- Post added 03-25-14 at 10:03 PM ----------

QuoteOriginally posted by fgaudet Quote
Try to shoot with a tripod and using the timer, this should improve the sharpness a bit.
I wouldn't recommend a timer when shooting animals.
03-25-2014, 08:11 PM   #6
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QuoteOriginally posted by lytrytyr Quote
The markings on the focus scale do not govern a lens's IQ at infinity.
That is determined by the optical formula of the lens.
How did you get that from this quote? The marking state at which distance the lens fall into infinity, nowhere did I mention IQ, only that once at infinity, since there is no actual focus point, a lens will give acceptable sharpness (circle of confusion). What is acceptable will depend on the lens itself, which will vary wildly between lenses, some will render exceptionally well (DA*300) and others particularly badly. As I stated in the sentence following the one you quoted...

QuoteOriginally posted by fgaudet Quote
It'll go from 0.1' to 30' (for example) and then you will get the infinity symbol... What that means is anything further than 30' will only be "acceptably" sharp. Some lens do it better than others, the 50-200 isn't doing it extremely well.


---------- Post added 03-25-14 at 23:19 ----------

QuoteOriginally posted by lytrytyr Quote
I wouldn't recommend a timer when shooting animals.
Works good for me. Unless the animal is actually running. But I figured that with 40 years of experience, the OP probably figured it out by himself
03-25-2014, 10:18 PM - 1 Like   #7
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I like the DA 50-200. This is an example, maybe a little closer than 100 feet. It's at 200mm, f8, 1/250, ISO 100 on a K-7.



I don't have any P&S experience, but many people have the same issue. They upgrade to a DSLR, take a bunch of shots and don't see improvement. A few reasons:
The P&S sensor is smaller, so it has more depth of field, so a lot more is in focus. That covers autofocus mistakes.
The lens and processing are optimized to work together, so lens problems are automatically corrected before you see them.
Processing makes the rest of the photo look better too, while the DSLR might have no processing at all.

You can see some of this yourself. The DA 50-200 has vignetting at its widest aperture settings (lowest f number). Vignetting just means the corners are darker than the center. If you take a shot at 50mm and f4 of an evenly lit wall or similar, you should see this. I use software that can correct this if I want. (The camera has a setting for lens corrections, but I am not sure if it corrects for vignetting.) A P&S camera would correct for this type of known flaw. You should be able to use camera settings or processing software to get your K-50 images to look better, like the P&S.

Then you have to address focusing. The camera has a lot of ways to customize focus, but everything has advantages and drawbacks. Most of the options require you to see if the focus is where you want it before you shoot. That's a very useful skill, maybe needing some practice. My camera is set to use the center point only, so I know that's where it has focused. Then I can check the viewfinder to see if my subject really is sharp, and adjust from there. The camera may stupidly lock onto a tree branch instead of the bird on the branch, so seeing focus is important.

For other settings, if you have enough light, an aperture of f8 to f11 and a shutter speed of 1/250 should produce good results. With steady hands, you can use slower shutter speeds. I know what I can get away with, but that's not important to you. Anyway, animals often move so really slow shutter speeds aren't that useful. The lens isn't as good at wider or narrower apertures. Higher ISO settings produce more noise and less dynamic range. I know where my camera starts to look bad but your camera is more important to you.
03-25-2014, 10:56 PM   #8
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QuoteOriginally posted by lytrytyr Quote
OP has the problem that the cropped K-50 images are little better than those from the P&S.
PP, especially on RAW files, can help improve the K-50 images.
And yes, a little sharpening can most certainly mitigate a focusing problem.
Even serious exposure and colour problems can be addressed in PP, but not blur.

White balance can be wrong, the Exposure Comp can accidentally be on, but fixing a dud focus is super hard.

Something to get right behind the viewfinder, not the laptop screen.


Last edited by clackers; 03-25-2014 at 11:09 PM.
03-26-2014, 05:38 AM - 1 Like   #9
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QuoteOriginally posted by Just1MoreDave Quote

For other settings, if you have enough light, an aperture of f8 to f11 and a shutter speed of 1/250 should produce good results. With steady hands, you can use slower shutter speeds. I know what I can get away with, but that's not important to you. Anyway, animals often move so really slow shutter speeds aren't that useful. The lens isn't as good at wider or narrower apertures. Higher ISO settings produce more noise and less dynamic range. I know where my camera starts to look bad but your camera is more important to you.
This is the right approach to start.
I prefer TAv for this reason - set your aperture to f8 as a good starting point, then adjust your shutter speed to keep you ISO low - 200ish is a good compromise. In bright sun, your shutter speed could easily be 1/1000. Make sure your shake reduction system has settled down, I've been too fast a few times and the first image I took was blurred because the SR had not stabilized.

You may not get great results from distant images, there's a lot going on including haze, wind, atmospheric moisture etc. which can cause an image to look flat and blurred. I've seen this taking pictures of aircraft which are clearly in focus but overall hazy and washed out. Summer is terrible, winter is pretty good because of the moisture.

It's all experience in the end, we're all still learning.
03-26-2014, 07:54 AM   #10
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QuoteOriginally posted by fgaudet Quote
How did you get that from this quote? . . . nowhere did I mention IQ
When you characterize the sharpness as 'only ''acceptable",'
you are excluding the possibilities of "good" and "excellent".
03-26-2014, 09:30 AM   #11
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I hope you all don't mind that I'm not replying individually to all the helpful replies. Taken together, I'm getting a much better grasp of my situation from them and I appreciate it. The comparisons to the P&S are particularly useful.

I haven't tried using my tripod with this camera yet, so that's next. I still need to learn more about the settings.

One thing I didn't mention was that the first K-50 was defective* and returned, so I'm trying to make sure it's me when things don't look right.
(*The Ricoh folks agreed when I described its behavior -- not worth going into here.)

Thanks again.
03-26-2014, 10:12 AM - 1 Like   #12
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The jump from a P&S is not as easy as it sounds at first. It's a little bit like going from a passenger on a cruise ship to being captain. Now the ship goes wherever you want, but only after you make all the right decisions.
03-26-2014, 03:04 PM - 1 Like   #13
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You just have to hang in there and keep experimenting. I started off the same way -- almost desperate enough to leave the K50 on "auto"...and just learn to use it as a glorified P&S. But like everyone else has said, I knew there would be a learning curve here, so I just grabbed a beer, and started trying to think things through.

Outside of the camera/lens being defective, there is almost always some combination of camera settings/equipment (think tripod) that will get you decent results, even with lenses that are "less than stellar". I've had my K50 for a little less than two months -- and I had no background outside of snapshots with a P&S...and whatever phone I was using. I did a ton of reading (like you're doing now), and then took the advice of my best friend (who turned me on to all of this). He said, "Cool that you're doing all of this reading -- now go out and start shooting. Only way you'll really figure out what works, and what doesn't." He was exactly right. I was reading about all of these settings/techniques/pitfalls/tips/you name it -- instead of just clicking away.

I went and bought a mix of cheap lenses from eBay (manual & entry level zooms), to go with my two kit lenses (exactly what you have), plus one decent entry-level prime (DA 35mm 2.4). I quickly discovered that I had overloaded my brain a bit because each lens had different behavior, so if something wasn't working on one, I would get frustrated transitioning to another. I finally settled on one lens at a time, put the K50 in AV mode, and then started shooting with different aperture settings/focal points. Stuff like taking my daughter to the park. I'd figure out what kind of light I had to work with, and then take a couple hundred shots with my cheap Tamron 75-300. All the while checking my LCD to see if things were close, or just horrendous. Then I'd bump the ISO, open up the aperture, just little things like that.

Later on that night, I would offload to my computer and take a look at the results. Using the SilkyPix app that came with my K50 allowed me to see the settings I was using, which was the road to seeing what I needed to tweak to get the pictures I was hoping for. I quickly started seeing what wasn't working, and what at least "kind of" was. The best part -- it's digital, so all of the snaps are free. Pretty soon, I started getting a feel for what the lens could/couldn't do. Honestly speaking, I'm not very sharp when it comes to juggling multiple ingredients (aperture, ss, ISO, lighting, etc.) to get a result I'm looking for. I don't know that I'll ever go the complete manual route, but after less than two months, I can take a lens I paid $20 for on eBay, and usually get something worth making my P&S something to forget about, just using AV mode,

Instead of stressing that I wasn't getting my shots right, I just tried to remember that I was doing this because it was fun. Sometimes you just have to shake your head, and laugh at your results. I've had plenty to laugh about over these past few weeks, for sure. But I've also had some results that made my wife, and my best friend, raise their eyebrows, and say "damn....did you take that?!?!"

You'll get there, trust me on that.

Last edited by esrandall; 03-27-2014 at 07:18 AM.
03-27-2014, 05:38 PM - 1 Like   #14
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QuoteOriginally posted by Just1MoreDave Quote
The jump from a P&S is not as easy as it sounds at first. It's a little bit like going from a passenger on a cruise ship to being captain. Now the ship goes wherever you want, but only after you make all the right decisions.
Great way to describe it.


QuoteOriginally posted by esrandall Quote
You just have to hang in there and keep experimenting. I started off the same way...
I appreciate the encouragement and tips.

One concern now is making sure I picked the right camera for me, before the 90-day return period is over, so I'm less patient than usual.
03-28-2014, 05:24 AM - 2 Likes   #15
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Get outside this weekend and use the camera. As I mentioned, I generally use TAv when outdoors. I find this easiest. Take pictures across a range of distances and start to get used to the camera. Jump in the deep end, the water's great!
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