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01-06-2012, 01:30 AM   #31
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QuoteOriginally posted by Mr Spocko Quote
So yes the original posters issue is an optical one.
This line really bugs me, but it's a prime example of the problem with people like Spocko. He sees something, picks what he thinks is a likely explanation for it, and then decides "Yes! It's a FACT! This is the only thing it can be!". He did the same thing in this thread where it really looks like the AF caught the mic, but Spocko insists it must be tungsten ff (under varying multicoloured floods).

Anyway, I want to put this one, or at least my involvement in it, to rest. I went digging through my collection looking for wide open shots with the kit lens at 55mm. This would not be typical settings for me, and I rarely use the kit lens, but I did find a few. They're not (with the possible exception of the last one) what I'd call keepers, and I'm not interested in any aesthetic critique. The only editing done (again, with the exception of the last) is slight tweaking to levels. Absolutely no sharpening, noise reduction, or filters of any kind. Shot raw, saved to jpeg for this thread. The scaled ones are linked to larger versions, the 1:1 crops didn't need it. All EXIF is intact on the large ones.



1:1 crop




1:1 crop


(this next one is actually f/9, my mistake).


1:1 crop




1:1 crop




1:1 crop




1:1 crop


I'll reiterate, I don't think any of these are wonderful, but I think they're reasonably representative of what can be done with the kit lens. The plant shots were taken when I had had my K-r for a month, still experimenting wildly.

Your turn, Spocko. You who complains so much but never posts a photo. Let's see these soft unusable shots you're suffering from. Maybe we can help you figure out what's really going wrong.

01-06-2012, 03:07 AM   #32
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QuoteOriginally posted by hawaza Quote
Now this thread has interested me since i too have just brought my first ever slr, a Pentax K-r. This issue had given me some cause for concern, especially since one of the reasons i got this camera was because of many independent reviews stating that the kit lens was particularly good when compared to lens supplied with other entry level dslr's. Today i actually had the chance to test it for myself and see how much of an issue this softness was. The results are below:







Now this is my first outing with an dslr (let alone this K-r) and lets be honest there is nothing amazing about the pictures. However i think (that should read hope) that you will agree that these pictures are relatively sharp, or at least more so that the one the OP posted at the start of this thread. It just took some time to fine tune the settings to accommodate the dull and windy conditions (set the shutter speed and aperture manually and up the ISO) and a bit of patience and perseverance. With more favourable conditions and more practice i imagine these could be even better.

Hopefully this proves decent sharpness can be achieved with the 18-55mm kit lens, although please feel free to comment otherwise as after all I am new to this

I looked at your exif f8-f10
Try shooting them at f5.6 and you'll see what I'm talking about

As for the samples above they back up my points entirely soft focus effect at f5.6 you can see the hazy effect quite clearly.
Ray is having denial problems again so I'll help you out:
http://en.wikipedia.org/wiki/Spherical_aberration

Pretty simple diagram showing the issue:
http://amazing-space.stsci.edu/resources/explorations/groundup/lesson/basics/g11/

Which is why we have:
http://en.wikipedia.org/wiki/Aspheric_lens

But Ray likes an argument even when real world images and pure facts are on offer so I look forward to another post where he shows us just how much he doesn't know about lenses and optics thanks Ray you're a scream

Last edited by Mr Spocko; 01-06-2012 at 03:15 AM.
01-06-2012, 03:34 AM   #33
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QuoteOriginally posted by Mr Spocko Quote
I looked at your exif f8-f10 Try shooting them at f5.6 and you'll see what I'm talking about
Actually one is taken at f5.6 (the one in the middle of the fallen and broken tree end) and it turned out fine.

The other two are at f8.0 (the one with the yellow flow and spikes) and at f10.0 (the one with the leaf).

I would say this was intentionally at a range of f values but I would be lying. I just used the settings which gave me the best picture at that time in that place and surely that is what you are meant to do? Why try and use settings you want in situations when they won't give you the best possible results? As i said I am only a beginner but that seems logical.
01-06-2012, 04:08 AM   #34
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QuoteOriginally posted by Mr Spocko Quote
I looked at your exif f8-f10
Try shooting them at f5.6 and you'll see what I'm talking about
Look, it's a cheapola lens that has expected limitations for the price bracket. Why would you want to persist in using settings you know deliver less than optimum results, unless you're some kind of masochist or just plain daft?

01-06-2012, 04:13 AM   #35
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The images you posted are too small to see things properly. I think people would use f5.6 at 55mm for a few very obvious subjects. Portraits being one of those.
This is where the "hazy/soft focus effect" can be a problem. Some would say it might be a bonus (if you want that)
But by far the biggest problem is working indoors in lower light where the hazy image effect can only be avoided by stopping down, thus robbing you of much needed speed. F5.6 isn't great in dim light anyway, but f8-f11 is even worse.

Back to the point the original image shows very clearly the effects of an optical weakness and fully described in the links I gave. It's not open to any kind of debate simply because it's so very obvious that everyone can see it. Those than can't I suggest are in some kind of "auto branded denial mode" Our friend above from Ontario has posted yet more samples that add weight to this very clear and cast iron conclusion.
Yes something people make mistakes and users might be wrong, but not in this case
01-06-2012, 04:46 AM   #36
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Anyone who expects a budget lens to deliver stellar results at maximum (or close to maximum) aperture is misguided in my opinion and will always be disappointed.
I don't think I'm going to bother adding any more to this debate as Mr Spocko will insist on having the final word, whatever rational counter views are put forwards.
As for my final words on the matter - Beam me up Scotty!
01-06-2012, 06:10 AM   #37
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K-rrr simple logic is all that is required.
I believe the poster who started the topic deserved a reply that correctly diagnosed the problem, and a way of avoiding the issue (ie shoot at a wider focal length/stop the lens down)
It was unfortunate to read replies that were well short of the required response. It's not a DOF issue, nor a focus one simply optics of this lens at work.
I agree it's a lens that is cheap and nobody expects amazing results however I feel both Canon and Nikon do offer superior kit lenses v the Pentax one and that the time for an update to this lens has arrived. It really is quite poor at the telelphoto end at f5.6
01-06-2012, 07:31 AM   #38
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I agree the poster deserves an answer but the I don't think the quality of the lens is the cause, not purely on the basis of my experience but on the experiences of other people in this thread and viewable in many example images scattered around this forum.

Here is an explanation as to why i believe his shots are as they are based on the fact mine were the same initially:

He used these settings:
F5.6,1/40 sec ISO 200 and using the standard 18-55 kit lens. (guessing at 50mm but i don't know).

Potential Issues:

ISO: Now considering he stated light conditions were poor it seems reasonable to assume a higher ISO would have greatly helped - I had to use ISO 1600 and it helped greatly improve my images in poor light.

Slow Shutter: If it was windy and the subject was moving slightly then a shutter speed of 1/40 might be slightly to slow and give slight but noticeable blur. Looking at the image i don't believe this is the case but it is possible - it caused me all sorts of issues when i shot those images yesterday.

User error: This is always a possibility. Having just started i can say getting shots in good focus close up was difficult. Very small movements of the subject/myself shifted the focus point and resulted in soft/blurred/out of focus images. I suppose the DOF can be quite narrow. Non-optimum setting choices can exaggerate this I found too.

Faulty lens: Since good images can be obtained by many with this lens the optical quality (while not the best) is obviously sufficient. However that particular lens could be faulty.

Solution:
The only way to know is for the creator of this thread to go out himself and have another attempt.

I would suggest play around with the ISO settings, the shutter speed and the aperture. Try shooting subjects (whoever or whatever they are) at various distances from them and at different focal lengths. Even try manually focusing rather than using autofocus - It can really help to get a feel for just how close you can to a subject.

If after that he/she is unable to produce some good, in focus, non-woolly pictures then we can assume with a certain level of certainty that the lens itself might be faulty and to get it fixed/replaced under the warranty.

FYI: One of the example shots i provided earlier was shot at focal length:55mm and at f5.6 (which some people here have stated this lens is quite poor) and it is sharp and in focus - not soft and blurred like the opening picture of this thread.

01-06-2012, 03:23 PM   #39
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QuoteOriginally posted by Mr Spocko Quote
I looked at your exif f8-f10
Try shooting them at f5.6 and you'll see what I'm talking about

As for the samples above they back up my points entirely soft focus effect at f5.6 you can see the hazy effect quite clearly.
Ray is having denial problems again so I'll help you out:
Spherical aberration - Wikipedia, the free encyclopedia

Pretty simple diagram showing the issue:
Figure: Spherical aberration in lenses

Which is why we have:
Aspheric lens - Wikipedia, the free encyclopedia

But Ray likes an argument even when real world images and pure facts are on offer so I look forward to another post where he shows us just how much he doesn't know about lenses and optics thanks Ray you're a scream
Wow Barry, you can Google.

Very impressive.

Your link to the outdated DPreview test of the lens that was not used in the original post certainly did nothing to support your conclusions, so with your expertise in optics, please explain to all how you "know" the cause of the softness in the original post?

It's like shooting fish in a barrel with you Barry, too easy.

Ray
01-06-2012, 05:17 PM   #40
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Ray I know it would kill you to actually admit you were wrong (let alone an apology for your tone) but yes I can use google, so can anyone so question is why didn't you? lol
Reality is most people know about this because it's pretty basic stuff and you don't need to be an optical expert, but do carry on with the "newbie" mistakes, user error, wrong AF point, bad technique angle. Everything you can think of bar the actual lens itself which is obviously the source of the problem.

The poster is hardly alone in being the first person to suggest the kit is dreamy and soft/mushy at 55mm f5.6 many copies are.
01-06-2012, 05:39 PM   #41
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QuoteOriginally posted by Mr Spocko Quote
Ray I know it would kill you to actually admit you were wrong (let alone an apology for your tone) but yes I can use google, so can anyone so question is why didn't you? lol
Reality is most people know about this because it's pretty basic stuff and you don't need to be an optical expert, but do carry on with the "newbie" mistakes, user error, wrong AF point, bad technique angle. Everything you can think of bar the actual lens itself which is obviously the source of the problem.

The poster is hardly alone in being the first person to suggest the kit is dreamy and soft/mushy at 55mm f5.6 many copies are.
No optical explanations to support your conclusions Barry, only more deflections?

Color me shocked.....

Ray
01-06-2012, 07:35 PM   #42
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QuoteOriginally posted by Mr Spocko Quote
I looked at your exif f8-f10
Try shooting them at f5.6 and you'll see what I'm talking about

As for the samples above they back up my points entirely soft focus effect at f5.6 you can see the hazy effect quite clearly.
The first, second, fourth and fifth shots I posted are using 55mm at f./5.6. I suspect you paid about as much attention to that, as you did when studying OPs problem shot.

I wouldn't say these shots are tack sharp, but you're not going to get macro lens clarity in 1:1 crops very often with a kit lens, handheld, no hood, etc. Casual usage, in other words. That doesn't mean they're overly soft, it's just being realistic. Resized to normal viewing sizes, or as average sized prints, the lens does just fine for what it is, and what it costs.

At least there's one potentially positive outcome from these threads you troll - other people learn what not to do, how not to analyze a problem, and they probably also pick up a lot of info that is posted to correct your misinformation (or was that disinformation). I think it's wonderful that you manage to argue these things without a speck of evidence or reason, and just stick to your usual "I'm right because I'm right, and anyone who disagrees is making excuses for Pentax". It makes it a lot easier for everyone else to see what kind of poster you are.
01-06-2012, 08:30 PM - 1 Like   #43
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Has anyone actually diagnosed the original problem?

It's pretty obvious to me the OP'er manually set an ISO of 200, however low light resulted in a too slow shutter speed leading to motion blur.

Solution: change ISO setting back to auto.... and watch that shutter speed in future.
01-06-2012, 08:53 PM - 2 Likes   #44
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Here are some that I took with my kit lens. I didn't do any editing. (Keep in mind I took these my first time ever using a DSLR and not really knowing what aperture or focal length really were. So if there are errors they are probably me doing something wrong)

I don't know if you can see the EXIF data but they were all the widest aperture for that given focal length.

























Don't mind his missing eye, he lost it as a child, but he is still a great friend!
01-07-2012, 05:34 AM   #45
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QuoteOriginally posted by Philoslothical Quote
The first, second, fourth and fifth shots I posted are using 55mm at f./5.6. I suspect you paid about as much attention to that, as you did when studying OPs problem shot.

I wouldn't say these shots are tack sharp, but you're not going to get macro lens clarity in 1:1 crops very often with a kit lens, handheld, no hood, etc. Casual usage, in other words. That doesn't mean they're overly soft, it's just being realistic. Resized to normal viewing sizes, or as average sized prints, the lens does just fine for what it is, and what it costs.

At least there's one potentially positive outcome from these threads you troll - other people learn what not to do, how not to analyze a problem, and they probably also pick up a lot of info that is posted to correct your misinformation (or was that disinformation). I think it's wonderful that you manage to argue these things without a speck of evidence or reason, and just stick to your usual "I'm right because I'm right, and anyone who disagrees is making excuses for Pentax". It makes it a lot easier for everyone else to see what kind of poster you are.

I'd like to thank you for posting shots that siimply back up the points made you can clearly see the softness, and soft focus effect on the shots you posted.
I think it's very easy to see what kind of poster you are one that will deny obvious facts, exactly the same situation with the K-r AF problems

The images themselves are the evidence
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