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08-15-2015, 01:51 PM   #31
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QuoteOriginally posted by Oricman Quote
More problems.
On the kit DA lens it says the aperture is 3.5-5.6. ... On other cameras I can keep the ISO at 100 to give the best quality and put the aperture where you want it.With the kit DA lens I'm not sure what my aperture limit is but usually have to opt for around 10 - 16... So many of my images are not sharp . I feel like givinhg up and selling the Pentax on.
I really question all this, Oricman.

That lens is the lowest quality lens the company sells, yet AFAIK compares very well with the kit of other companies.

If on a Canon or Nikon a setting for a shot is f4, 1/250 and ISO 400, that's the setting on your Pentax, too.

Buy a better lens if you want more quality, that's what many of us forum members have done.

Know your lens if that's not going to happen. Here are its MTF results:

http://www.photozone.de/pentax/135-pentax-smc-da-18-55mm-f35-56-al-review--test-report?start=1

On APS-C especially, you can see that you shouldn't routinely go beyond f8 without good reason because (for any brand) diffraction starts to soften the image.

It's also possible you have user error with your lens (your selected shutter speeds are too slow - I aim for 1/180s, but try for a minimum of 1/60s - and improve your technique so a monopod or tripod isn't essential) or you have a bad copy, but these are testable.

Here is the kit lens club in our forum, where members show pictures taken with their 18-55.

https://www.pentaxforums.com/forums/122-lens-clubs/45425-kit-lens-club.html

That's where you want to head for ideas, inspiration and to see what's possible with what you have. :-)


Last edited by clackers; 08-15-2015 at 09:57 PM.
08-15-2015, 09:05 PM   #32
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QuoteOriginally posted by Oricman Quote
More problems.
On the kit DA lens it says the aperture is 3.5-5.6. I'm assuming this is the lower end over the length of the zoom. The high end isn't mentioned. I assume the camera knows what lens is on so gives the appropriate options. I want to try and get sharp images - (so far quite elusive) -so should be using the higher f settings, but these seem to require jumping up the ISO settings too. On other cameras I can keep the ISO at 100 to give the best quality and put the aperture where you want it.With the kit DA lens I'm not sure what my aperture limit is but usually have to opt for around 10 - 16. Shouldn't this be enough to get a reasonable image ? So many of my images are not sharp . I feel like giving up and selling the Pentax on.
Don't despair. First - post a picture or two that didn't work and let us look. ISO 100 does give the "best" quality in terms of noise but the sensor in that camera gives really good results to ISO 800 and good results for 1600 (in my opinion). f/stops are a bit tricky on APSC - depending on the size you plan to enlarge to f/8 may be has high as you want to go before diffraction kicks in - some lens/sensor combos can go a little higher perhaps f/11 - anything beyond that and diffraction really starts to kick up too much and caution is advised if you need "SHARP" as opposed to "almost sharp".

The kit lens is pretty good but not the greatest if you want tack sharp wide open but closed to about f/8 it should be fairly sharp. Focusing can be off - is it possible that the focus was missed? Sometimes it focuses too close or too far - easier to see if you have depth in the photo like along a fence at an angle.
08-16-2015, 01:49 PM   #33
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Thanks for the replies. It's hard to tell if the lens is the problem - I would hope that even a cheap DSLR lens should give results better than the smaller/ cheaper cameras that I have used in the past. If they can't outperform a superzoom then I'm better using the superzoom, arent' I ?
I used to use cheap SLRs in the film days and got better results. Are modern lenses that bad?

Focusing seems reasonable if I use a tripod and a focus chart. In real situations I get ambiguous results and some exposure seems under as well. I'll post a couple of shots.

First rose. Second rose has more aperture to try and get more in focus. Both are a bit soft.
Third picture is sunny day landscape. Not sharp and underexposed.

I was trying to increase the aperture to get more in focus - so that's a bad idea? I'm not sure the upper limit of the lens it seems to go over f32 sometimes.

I do take a lot of macro style shots, like the roses. Pictures of flowers, butterflies, etc. I know you can't get too close but the camera indicates the shot is in focus.
I have some sunsets which don't look quite right either. (End have marks from dust - Not sure whether it's on the lens or sensor but I've cleaned all around trying to shift these marks. )
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08-16-2015, 02:34 PM   #34
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Here's Pentax vs Panasonic

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08-16-2015, 06:30 PM   #35
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Have you tried using LiveView to focus? One of the possible issues is misalignment of the focusing system focusing too far forward or backward. That set of images isn't typical for the sharpness of that kit lens. I am not able to take a photo with my K50 using my kit lens right now but when I can I will try to show what I would expect.

Did you notice if you had a fully lit up focus indicator? Not the red indicator of focus point but the green one lower in the viewfinder.
08-17-2015, 12:04 AM   #36
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Oricman, with the kit lens I'm not sure you're going to get much better than say, these from the Lens Club:


https://www.pentaxforums.com/forums/122-lens-clubs/45425-kit-lens-club-16.html#post952839


Your comparison was out of camera JPEGs?


You can do somewhat better yourself post processing the RAW images ... the highlights are cranked up too much on your Pentax picture, for starters. I think both Pentax and Panasonic pictures are nothing special on the detail front, but at least you could put a polarizing filter on the Pentax lens to cut the glare off the yellow bits.

You'll be able to do your own sharpening, contrast and clarity adjustment in software, too, and should then be able to match or exceed the point and shoot.


But ultimately, you don't want to put a cheap lens in front of a good camera.


Your K-30 will deliver fantastic images with say, the 100mm f2.8 macro.


With your film background, you could find wonderful cheap legacy lenses dating back to 1975 or earlier.

Last edited by clackers; 08-17-2015 at 12:49 AM.
08-17-2015, 03:02 AM   #37
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Thanks for the replies. It does seem to be a feature of this lens. I found mention of the soft focus on the Digital Photography Review: Digital Photography Review lens review.

"This lens's only slight Achilles’ heel in terms of image quality is a distinct softness wide open at 55mm, with the lens set to shorter focus distances. Technically this is due to under-correction for spherical aberration, which results in a characteristic soft-focus, slightly 'dreamy' feel to the images, with highlights ‘smearing’ into shadows."
It does say Canon kit lens (etc) suffers in a similar way but not so bad. Mt partner's Canon 500D seems to do better.

I got the Pentax after examining the comparisons on Dpreview which seem to show the K30 and K50 as having sharper/clearer images than similar Canon, Nikon and Sony.

I may try some Raw files before I give up. I find it tricky to get natural looking results in Raw and the extra time and file sizes has put me off a bit. I use PaintShopPro X5 to tweak Jpegs and can improve images a lot with that. Aftershot 2 is better for handling Raw.

UncleVanya - Yes, I've tried live-view and I've taken shots of a focusing chart which doesn't show any obvious front/back issue.


08-17-2015, 06:27 AM   #38
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What are the good Pentax Zoom lenses? I had my eye on the 17-70 but reading a review it doesn't seem to be much better than the 18-55 so far as sharpness is concerned.
Sigma options seems to be soft from what I can read about them.

08-17-2015, 06:44 AM   #39
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QuoteOriginally posted by Oricman Quote
End have marks from dust - Not sure whether it's on the lens or sensor but I've cleaned all around trying to shift these marks.
That is dust on the sensor.
It is inevitable that you'll get some dust on the sensor during your use of a DSLR, even if you are very careful when changing lenses. You can only be as careful as possible when changing lenses, and I'm sure you'll find various tried and tested ways of doing it properly on YouTube, or articles on the web, and also articles on how to clean it yourself, if you don't want to send it for professional cleaning.

Although the 18-55 kit lens have a few passionate believers in it, I think it depends on a lot on luck of the draw as to whether you get a good or bad copy. As a cheap kit lens I don't think much time and care is taken during production to ensure that every copy is at it's absolute best. I've had a few, and bar the 18-55 WR, have always been disappointed with the kit lens.

Using lenses from film cameras on digital SLR cameras

https://www.pentaxforums.com/forums/54-pentax-lens-articles/56234-konica-mino...ld-lenses.html

https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/171851-c...pentax-kr.html
08-17-2015, 06:52 AM   #40
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Oricman According to the forum shutter count tool, this image was #2523
08-17-2015, 12:53 PM   #41
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QuoteOriginally posted by Oricman Quote
What are the good Pentax Zoom lenses? I had my eye on the 17-70 but reading a review it doesn't seem to be much better than the 18-55 so far as sharpness is concerned.
.
You've got a nice camera, you can do those flowers justice.

The 16-45 (second hand) is a cheap step up from the kit. The 20-40 and 16-85 are higher quality upgrades. The 16-50 is a pro level f2.8. Sigma and Tamron make really good pro-level f2.8 zooms (the Tamron is the more affordable).

As a compromise, the Sigma 17-70 is a very acceptable tradeoff of quality vs zoom range.
08-17-2015, 02:59 PM   #42
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Thanks Clackers. I'm uncertain whether invest more money in this. For the price of a good lens I could get a Lumix FZ1000.
I got the cheaper end of the DSLR market wanting to use the cheaper lenses and the 55-300 seemed good. Mine has suffered water ingress and I don't think it can be sorted very easily.

What about the shutter count altopiet ???

I have tried cleaning the sensor, focusing screen and lenses trying to figure where the spots are coming from and going round in cycles trying to figure which is the problem. I think it has been dust on the lens at times.

I think Ebay beckons.
08-17-2015, 03:24 PM   #43
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Well, that FZ1000 is expensive, Oricman. But a 1" sensor gives reasonable stills and the video is very good.
08-17-2015, 09:46 PM   #44
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QuoteOriginally posted by Oricman Quote
What about the shutter count altopiet ???
The image you posted was #2523
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