Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
08-22-2012, 04:15 AM   #16
Banned




Join Date: Jun 2012
Location: NY/Germany
Posts: 1,183
It should be called whatever the physical aperture is, but the usable range would be explained in the sharpness tests.

I have a Soligor 24 2.5, which not much is known about compared to the 2.8 variant that is pretty common. Oddly, it is VERY soft at 2.5, marginally better at 2.8, but only has useful and great sharpness at 5.6 and above.

Had I known this, I would have gone for the Sigma 24 2.8 AF, which is sharp wide open.

It was also this reason I didn't get the FA43 and opted for the FA35 instead- I shoot wide open all the time and I needed something sharper and without that "dreamy character" of the FA43. If I get more creative, I might go for it for portraits.

08-22-2012, 05:17 AM   #17
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,400
With very few exceptions, i find that the F stop, and actual exposure between (for example 5 different 28mm lenses) is consistent and therefore there is no real need to discuss T-Stops at all. It just confuses the matter. In all honesty, i have only ever found one lens (out of 50 or so that I own, so forgive me if It does not cover any other of the 23million plus lenses out there) that has a need for different exposure at the same F stop, this is an old XR rikenon M42 mount 135 which is one stop slower (based on shooting shutter speed at any aperture) compared to my other 3 135mm lenses. mostly though, the difference in light transmission lens to lens is less than 5% and when you consider a full stop is 50% you can see why I suggest forgetting all about T stops, we do all sorts of other things that cause more than a 10% error in our exposure and this is well within the range of correction (even in JPEG) during post processing.
08-22-2012, 05:26 AM   #18
Loyal Site Supporter
eddie1960's Avatar

Join Date: Aug 2010
Location: Toronto
Photos: Gallery | Albums
Posts: 12,270
QuoteOriginally posted by Lowell Goudge Quote
As people talk hoods, one thing to consider in the ASP-C world is that you can gain a ton, by extending the hoods far beyond the stock hoods for most legacy lenses because the hoods were either deisgned for multiple lenses, and they are designed for full frame field of view. I use the hood of my SMC tak 200/4 on my supertak 85 for example,

Steep down 1-2 focal length steps with all your hoods because the light that covers a full frame (film for example) just goes into baffles in the mirror box on a DSLR
I use my 135 hood on my 85 and 50, my 50 hood on 35 and 28. My 28 hood I really only use when shooting film with the 28 and 35.
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!
k-mount, lens, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
India calling ajay ghatage Welcomes and Introductions 5 07-30-2012 10:06 PM
Calling all Pentaxians! Pauld General Talk 21 01-14-2011 02:35 PM
Ireland Calling penoh1891 Welcomes and Introductions 7 09-25-2010 12:27 PM
Architecture Who're you calling chicken? irfan.in.tx Post Your Photos! 2 09-08-2010 02:36 PM
People yellow boots and spade Michelle Photo Critique 4 06-09-2010 05:51 AM



All times are GMT -7. The time now is 12:14 AM. | 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