Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
06-29-2012, 11:08 AM   #16
Pentaxian
Mareket's Avatar

Join Date: Jun 2011
Location: Chester
Photos: Gallery | Albums
Posts: 719
And a picture at f/128 with said lens (bear in mind I positioned the K-5 half-arsedly with a gorillapod, so the plane of focus is most definitely not parallel to the plane of the sensor):




06-29-2012, 11:13 AM   #17
Loyal Site Supporter
Loyal Site Supporter
eddie1960's Avatar

Join Date: Aug 2010
Location: Toronto
Photos: Gallery | Albums
Posts: 12,273
QuoteOriginally posted by lytrytyr Quote


Even RioRico would have a challenge adapting this to Pentax!
you'd be surprised what @RioRico can do with a bellows or an flanged adapter and some glue and extension tubes

Edit, I have seen a lens much like that adapted to a canon and shots from the streets of new york

http://blog.planet5d.com/2010/09/what-do-you-get-when-you-put-a-102-year-old...os-5d-mark-ii/
06-29-2012, 12:05 PM   #18
Pentaxian
kh1234567890's Avatar

Join Date: Sep 2010
Location: Manchester, UK
Photos: Gallery
Posts: 2,416
QuoteOriginally posted by victordeamorin Quote
Also, on a more trivial note, I believe the kit 18-55 lens goes at leat to f/44 when zoomed at 55mm. Too lazy to check the exact value now... But it is probably also applicable to other variable aperture consumer zooms.
f40 if you set third of a stop aperture increments


06-29-2012, 12:16 PM   #19
Loyal Site Supporter
Loyal Site Supporter
eddie1960's Avatar

Join Date: Aug 2010
Location: Toronto
Photos: Gallery | Albums
Posts: 12,273
interesting, not a great test of diffraction though since iso 1600 on the k7 is already limited. at full size what looks sharp at web sized is softer though - but it could be many things (iso, diffraction, or just the fact that the kit isn't at it's sharpest at 55 anyway). But it does show that diffraction isn't a major concern if you are posting on the web, or using the image in less sharpness critical situations.
the real measure would be the same shot better lit so you could shoot iso 100 and shoot it at 5.6/8/11/16/22/40 and be able to compare relative sharpness under a controlled test
Ultimately though there are many other things that are more important to an image than ultimate sharpness

“Sharpness is a bourgeois concept” - Henri Cartier-Bresson

06-29-2012, 12:33 PM   #20
Pentaxian
kh1234567890's Avatar

Join Date: Sep 2010
Location: Manchester, UK
Photos: Gallery
Posts: 2,416
It did have a cheap Sony VCL-M3358 close-up lens stuck on the front of it Found it in my drawer (from my Sony DSC-H1 days) and thought 'what would happen if ...'. ISO1600 'cause I couldn't be ars*d to get the tripod set up and was shooting hand-held. As you say, it looks sharper than it is.
06-29-2012, 12:44 PM   #21
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 26,211
Putting the Pentax FA 1.7 TC on a DA* 60-250 will get you to F 57. But despite many exposures, we often shoot with wide open 5.6, 8, 11, 22, 32 and select the best image... we've never selected a shot above F 22 as the best shot...and most shots fall in the range of 5.6 to 8 with diminishing returns after that. We've never even selected an F-32 shot. By that time the image is so softened by diffraction you really don't care if it's consistently sharp across a very wide depth of field, it's just bad.
06-29-2012, 12:44 PM   #22
Loyal Site Supporter
Loyal Site Supporter
eddie1960's Avatar

Join Date: Aug 2010
Location: Toronto
Photos: Gallery | Albums
Posts: 12,273
QuoteOriginally posted by kh1234567890 Quote
It did have a cheap Sony VCL-M3358 close-up lens stuck on the front of it Found it in my drawer (from my Sony DSC-H1 days) and thought 'what would happen if ...'. ISO1600 'cause I couldn't be ars*d to get the tripod set up and was shooting hand-held. As you say, it looks sharper than it is.
There are a few examples on flickr of diffraction of say F16 versus F32 . when you look at the web size it's not really apparent but when you look at the full size the sharp edges all have a soft glow.

If I needed to shoot F22 to get a composition i wanted I probably would bearing in mind I won't be printing it at 30x40 for sale
06-29-2012, 01:52 PM   #23
Pentaxian
cali92rs's Avatar

Join Date: May 2011
Location: Long Beach, CA
Posts: 3,347
The OP hasn't responded in 2 pages to what he wants to accomplish...greater DOF for macro or landscapes, or longer exposures.
I am not a great landscape shooter, but for macro focus stacking works wonderfully if done properly. I am curious for the landscape shooters that like vast DOFs, does focus stacking work for that application as wel?

06-29-2012, 02:06 PM   #24
Site Supporter
Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 27,663
QuoteOriginally posted by Medium FormatPro Quote
If f22 or f32 isn't quite good enough...
It all depends on what you mean by "good enough". The smaller apertures don't do much for performance, but they are pretty much essential for depth of field, hence their presence on lenses for large format cameras.

As noted above, if you need longer exposure times, a neutral density filter is your best friend.


Steve
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!
f22, f32, k-mount, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lens greater than F32 schitzengiggles Pentax SLR Lens Discussion 22 06-09-2012 11:59 AM
Carl Zeiss Lens, 35-70mm F2.8-F22 ozlizard Pentax SLR Lens Discussion 7 10-06-2011 04:48 AM
What about this? Tokina is good stuff isn't it? Raptorman Pentax SLR Lens Discussion 5 04-22-2010 02:39 PM
Macro at f32! And some other stuff... codiac2600 Post Your Photos! 10 07-01-2007 01:34 PM
landscapes... which lens is sharpest at F16 to F32 etc? slip Pentax SLR Lens Discussion 7 01-06-2007 07:41 PM



All times are GMT -7. The time now is 05:35 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