Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
09-23-2012, 09:31 AM   #16
Pentaxian
Edgar_in_Indy's Avatar

Join Date: May 2010
Location: Indiana, USA
Photos: Gallery
Posts: 2,636
Original Poster
QuoteOriginally posted by GabrielFFontes Quote
You sent all lenses to adjust without testing them? What if they didn't need the adjustment? :P
They did need adjustment, and they needed more adjustment than my K-30 could provide. I had previously calibrated my lenses to my K-x, and unfortunately it did not match my K-30. So I don't know if my K-x was out of whack, or it's my K-30, but the two cameras were clearly different.

While the micro-adjustment is a very nice feature on the K-30, it could clearly benefit from a larger range of adjustment. I've seen several other people on the forum mention having a lens that was beyond the calibration capabilities of the camera. It seems like it would be a simple firmware adjustment to allow greater calibration.

09-23-2012, 09:34 AM   #17
Senior Member




Join Date: Jan 2011
Location: twente
Photos: Gallery
Posts: 107
very nice set, but its definitely not a handheld set. On first sight they look sharp enough, but viewed on 100% they are not. They look a bit soft, but I think that's because you use f4. The only shot you did with a tripod is nice, but could use a bit more light. I liked to see that one with f11 and 1 or 2 stops more light. Did you shoot on automatic mode? Did you use in-camera noise reduction?

I,m in doubt now what camera to choose to fill the time gap till a fullframe pentax will be available. The cheap k30 or the (much more) expensive k5 IIs.
09-23-2012, 09:44 AM   #18
Veteran Member
GabrielFFontes's Avatar

Join Date: Jul 2011
Location: Rio de Janeiro, Brazil
Posts: 647
QuoteOriginally posted by Edgar_in_Indy Quote
They did need adjustment, and they needed more adjustment than my K-30 could provide. I had previously calibrated my lenses to my K-x, and unfortunately it did not match my K-30. So I don't know if my K-x was out of whack, or it's my K-30, but the two cameras were clearly different.

While the micro-adjustment is a very nice feature on the K-30, it could clearly benefit from a larger range of adjustment. I've seen several other people on the forum mention having a lens that was beyond the calibration capabilities of the camera. It seems like it would be a simple firmware adjustment to allow greater calibration.
I just bought my K-30 (will only arrive 2 weeks from now), and i'm hoping it will work with my Sigma 70-200 without adjustment, since the frontfocus problem with this lens varies by focal lenght.
Anyway, nice pictures (specially the car ones)
09-23-2012, 01:05 PM   #19
Pentaxian
Edgar_in_Indy's Avatar

Join Date: May 2010
Location: Indiana, USA
Photos: Gallery
Posts: 2,636
Original Poster
QuoteOriginally posted by hansenn Quote
very nice set, but its definitely not a handheld set. On first sight they look sharp enough, but viewed on 100% they are not. They look a bit soft, but I think that's because you use f4.
With this lens, it is supposed to achieve near-maximum sharpness at f4. Photozone tested two copies (One Canon, one Nikon), and both lenses showed just a tiny improvement by stepping down to f5.6 at 300mm. On the Nikon copy, resolution measured just a hair higher at f8, but decreased after that. On the Canon copy, resolution decreased at f8.

I think that a major reason you're seeing some softness at 300mm/f4 is that you are dealing with a very thin focal plane, especially for near subjects. I think you can see this if you examine the picture of the fence post at 300mm. I believe the barbed wire was not perfectly perpendicular to the front of the lens, and I also do not think the fence post was perfectly vertical in relation to the camera. So if you examine the barbed wire and the fence post up close, you can see areas where sharpness is excellent, and other areas where it is soft. But what I think you're actually seeing is the focal plane slicing through portions of the subject.

If you look at the silver barbed wire knot just to the left of the post, you can see how sharp things can be at 300mm and f4. And if you also look at the rusted wire just in front of the silver knot, you can see that even though the two wires are very close to each other, the rusted wire is already slipping into the out-of-focus area, and is therefore softer.

One other thing I would point out in regards to sharpness, is that a lot of times I've noticed that when people post sample images to the forum, they usually post a version that has been downsized a good bit. In my opinion, that is cheating since you can't really judge lens sharpness without viewing the 100% output. I could downsize all of these images a bit and have them all looking razor sharp. But I wanted to post the full, unadulterated image to let people see how the lens really performs.

QuoteOriginally posted by hansenn Quote
The only shot you did with a tripod is nice, but could use a bit more light. I liked to see that one with f11 and 1 or 2 stops more light. Did you shoot on automatic mode? Did you use in-camera noise reduction?
The police car pictures were taken inside of a garage facility at night, so it was not overly bright. The picture reflects the light levels of the actual scene. My "tripod" was actually an inverted bucket, and I had a hard time getting a stable shot with it even at f4 and 1/4 sec, so f11 + an extra stop or two of exposure would have been tricky. The last police car picture was taken with most of the garage lights turned off, so it's darker than the others. And the other car pictures were taken outside at night at a dealership.

QuoteOriginally posted by hansenn Quote
Did you shoot on automatic mode? Did you use in-camera noise reduction?
I think the camera was probably in Manual exposure mode, but it may also have been Aperture Priority. And I was shooting RAW, so in-camera noise reduction doesn't apply (besides whatever NR is secretly built into the firmware). I also did not apply any noise reduction during processing since I was testing the lens sharpness and did not want to soften any fine detail.

QuoteOriginally posted by hansenn Quote
I,m in doubt now what camera to choose to fill the time gap till a fullframe pentax will be available. The cheap k30 or the (much more) expensive k5 IIs.
With the recent price reductions of the K-30, you should be able to buy one now and then sell it later without losing much at all. That will probably not be the case for the new K-5 IIs for quite some time.

09-23-2012, 01:41 PM   #20
Senior Member




Join Date: Jan 2011
Location: twente
Photos: Gallery
Posts: 107
thanks for the reply Edgar.
I watched almost all your pics in 100%. Even that barn you shot with two different appertures. The f6.3 was better than the f4, but still not sharp enough imo. Though the front of the barn should be sharp if the focus was right.
That yellow thing on the barbed wire: The f4/100ISO one is sharp on the right place. The f10/200ISO one is not as sharp as the first one, probably because of the too slow shutterspeed in combination with the handheld technique.
But what i want to say is: Better always use a tripod with that kind of lenses. Shooting with 1/2000s isn't always a guarantee that your pic is razorsharp.

BTW: In my k20d i can set a noise reduction on higher ISO rates. Not anymore in the k30?

the silver barbed wire knot is indeed razor sharp.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
100-300mm, camera, f4, images, iso, k-30, k-50, lens, noise, pentax k30, pentax k50, pictures, sigma
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pentax DA* 60-250mm f/4 vs Sigma 100-300mm f/4 APO slackercruster Pentax SLR Lens Discussion 7 04-13-2012 06:35 AM
sigma 100-300mm f4 or pentax 300mm f4? powdablu21 Pentax SLR Lens Discussion 10 09-08-2010 05:14 AM
For Sale - Sold: NEW Sigma 100-300mm f4; Pentax DA* 50-135mm Votesh Sold Items 5 01-31-2009 07:38 PM
pentax 300mm f4 or sigma 100-300mm f4 kuau Pentax SLR Lens Discussion 14 11-29-2008 09:05 AM
Sigma 100-300mm f/4 versus Pentax DA* 300mm f/4 Tbear Pentax SLR Lens Discussion 5 03-26-2008 07:24 PM



All times are GMT -7. The time now is 11:58 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top