Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-08-2011, 05:53 PM   #1
Veteran Member
rparmar's Avatar

Join Date: Jan 2008
Photos: Gallery
Posts: 8,783
BJP article

"Is a medium format camera right for you?" asks the British Journal of Photography, evaluating the Pentax offering alongside Phase One, Leica, Hasselblad. The 645D comes out as the least expensive and most usable option, though the author complains of an image softness he claims is also in the recent APS-C models. Funny, because that's exactly my experience of images from the K-x and K-7.

Read it all here.

04-08-2011, 06:50 PM   #2
Veteran Member
RXrenesis8's Avatar

Join Date: Jan 2011
Location: Orlando, FL (USA)
Photos: Gallery | Albums
Posts: 523
Image softness? Perhaps the Anti-aliasing filters have been made stronger in recent years?
04-08-2011, 06:54 PM   #3
Veteran Member
rparmar's Avatar

Join Date: Jan 2008
Photos: Gallery
Posts: 8,783
Original Poster
QuoteOriginally posted by RXrenesis8 Quote
Image softness? Perhaps the Anti-aliasing filters have been made stronger in recent years?
That wouldn't apply to the 645D which has a weak AA filter. My experience indicates it is the sensor. The images from, say, the K-x looks OK out of the camera, but takes less manipulation than those from my K20D. I can't quantify this in any way.

But it's mighty odd to hear the 645D might be similar!
04-08-2011, 09:09 PM   #4
Senior Member




Join Date: Mar 2011
Location: United States
Posts: 183
QuoteOriginally posted by RXrenesis8 Quote
Image softness? Perhaps the Anti-aliasing filters have been made stronger in recent years?
So softness could be smoothing/averaging on the hardware (aka Noise Reduction) to get better high ISO performance? I'd rather have good sharpness at low iso than less grain at high iso. If what they are saying is true about softness, let's push for better sharpness and forget about breaking high ISO benchmarks.

04-09-2011, 12:49 AM   #5
Veteran Member
RXrenesis8's Avatar

Join Date: Jan 2011
Location: Orlando, FL (USA)
Photos: Gallery | Albums
Posts: 523
I believe the K-5 has a weaker AA filter, I'm just talking about the K-x and K-7. I'm sure pentax engineers determine the best compromise and adjust the filters in each model differently.

As for the 645D I had read that it has a fairly weak AA filter, along with most medium format digitals and digital backs.

Here are some samples from another forum member: https://www.pentaxforums.com/forums/pentax-medium-format-645-6x7-645d/136971-...one-tried.html

They look plenty sharp to me!
04-09-2011, 07:03 AM   #6
Veteran Member




Join Date: Feb 2011
Photos: Gallery
Posts: 573
The 645D has no AA filter.
04-10-2011, 06:20 AM   #7
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 9,299
the pose above is correct, the 645D is completely free of the sharpness robbing AA filter. And that is a good thing if you photograph subject matter that isn't prone to moire, but if you do then be prepared to spend some frustrating hours post processing images.

I actually use my K10 rather than use my K-7, I like the K7 because it is small and quiet but per-pixel sharpness isn't one of it's strengths especially with lenses that are inherently softer E.G K and A versions of the SMC 50mm f/1.2 @ f/1.2 - which is surprisingly sharp @ f/1.2 on the K10D, but it appears to be much softer on a camera with a heavy handed AA. filter.
04-10-2011, 08:02 AM   #8
Veteran Member
rparmar's Avatar

Join Date: Jan 2008
Photos: Gallery
Posts: 8,783
Original Poster
QuoteOriginally posted by Digitalis Quote
I actually use my K10 rather than use my K-7, I like the K7 because it is small and quiet but per-pixel sharpness isn't one of it's strengths especially with lenses that are inherently softer E.G K and A versions of the SMC 50mm f/1.2 @ f/1.2 - which is surprisingly sharp @ f/1.2 on the K10D, but it appears to be much softer on a camera with a heavy handed AA. filter.
So perhaps following the K20D generation, Pentax added a stronger AA filter to the SLRs? Or perhaps it is an effect of changing sensors?

04-10-2011, 11:52 PM   #9
Veteran Member




Join Date: Oct 2008
Photos: Gallery
Posts: 351
4 months into 645D ownership and no complaints on this end regarding soft images.

An observation though if I may and this is made with no knowledge or the authors experience with MF gear and/or how much of the info is copy/paste from OEM spec sheets and the like ....

It took me some time to recalibrate to the reduced DOF that comes with the change in format and moving to a system with a larger distance between sensor and optics and the larger sensor. When I used to shoot F8 in the studio it was never an issue, but all of a sudden I'm at F8 on the 645D and getting pin sharp nose tips and slightly soft eyes.
The resolution is still very good though, so it's very easy to confuse "soft" with "no - I mucked up the focus point on that one".
When you get it right, there's no mistaking it, the images are crystal clear and razor sharp and you find yourself going back to the first images shot with the 645D and realising you muffed a lot of them and they could have been a lot sharper. This happened due to operator error i.e me focusing, then recomposing and shifting the focal plane/distance, not a problem with the autofocus picking the wrong spot - I'm now much more careful and use the selective focus points or manual focus a lot more as opposed to my old method of centre point focus and recompose

I've shown people some examples and when I skip past certain shots they ask to see them, typically the conversation goes like:
- Oh wait, can I see that one?
- No, I mucked that one up and it's not sharp.
- Rubbish, that looks fine to me
- Here, look, the eyes are soft.
- Looks fine to me and I'd be happy with a shot like that if I took it.
- Look at this one, in this one I nailed it and this is sharp and what it's supposed to look like.
- "stunned silence"........ HOLY CRAP!! I can count every eye lash and can tell which t-shirt you were wearing in the reflection in her eye, that's nuts!!
- I then point out in the "soft" image how you can see every pore on the tip of the persons nose and that the pic was taken at F8 or a wider aperture, but still at a setting that would have been fine on a DSLR and that stuffs people up even further.

Not saying this is the issue with the BJP article, just a general observation.

Last edited by Warped; 04-11-2011 at 12:01 AM.
04-11-2011, 12:41 AM   #10
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 9,299
QuoteOriginally posted by Warped Quote
but all of a sudden I'm at F8 on the 645D and getting pin sharp nose tips and slightly soft eyes.
I get the same with 8X10 at f/22...
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!
camera, medium format
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Obama article jeffkrol General Talk 13 10-13-2010 02:52 PM
A nice article... milarmon General Talk 2 09-05-2010 10:17 PM
an article on guns Gooshin General Talk 342 09-29-2009 07:51 AM
Win a Free K7 and DA 18-55 WR in BJP Jack Simpson Pentax News and Rumors 7 07-06-2009 09:47 PM
K7 camera test at BJP Online troenaas Pentax News and Rumors 4 06-26-2009 11:04 AM



All times are GMT -7. The time now is 03:03 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