Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
09-27-2009, 09:15 AM   #31
Loyal Site Supporter
dadipentak's Avatar

Join Date: Jul 2008
Location: Baltimore, Maryland
Photos: Gallery
Posts: 10,409
QuoteOriginally posted by adamkean Quote
i'm surpised everyone is saying its relatively light, it looks quite heavy
I'm surprised that anyone thinks it's heavy.

As I noted in my review, "I have a Sigma 70-200mm and a DA*300mm. They're great but they're both big and heavy so I never carry them simultaneously (more than 5 feet ;~). I'll often substitute the DA 55-300mm for the one I leave behind."

09-27-2009, 12:28 PM   #32
Senior Member
wowtip's Avatar

Join Date: Nov 2006
Location: West coast
Photos: Gallery
Posts: 254
Looks like a great lens, and put to good use too. It is on my all too long "lenses-to-get"-list, but it is climbing to a high priority position.

Does anyone know (or would be willing to check) what f value wide open is @ 200mm?
09-27-2009, 12:38 PM   #33
Ash
Community Manager
Loyal Site Supporter
Ash's Avatar

Join Date: Mar 2007
Location: Toowoomba, Queensland
Photos: Gallery | Albums
Posts: 22,695
QuoteOriginally posted by wowtip Quote
Does anyone know (or would be willing to check) what f value wide open is @ 200mm?
f/5.6

But, interestingly it stays f/4 from 55mm to just under 120mm, then goes to f/4.5 all the way to just under 190mm, then goes to f/5.6 until 300mm when it becomes f/5.8.
09-27-2009, 12:45 PM   #34
Pentaxian
audiobomber's Avatar

Join Date: May 2008
Location: Sudbury, Ontario
Photos: Albums
Posts: 6,685
QuoteOriginally posted by wowtip Quote
Looks like a great lens, and put to good use too. It is on my all too long "lenses-to-get"-list, but it is climbing to a high priority position.

Does anyone know (or would be willing to check) what f value wide open is @ 200mm?
My 55-300mm never reads 200mm in the camera or when the photo is downloaded. It jumps from 190mm at f4.5 to 210mm at f5.6. I assume at 200mm it's somewhere in between these two f-stops.

09-27-2009, 12:54 PM   #35
Veteran Member




Join Date: Aug 2007
Location: Dayton, OH
Posts: 365
QuoteOriginally posted by wowtip Quote
Does anyone know (or would be willing to check) what f value wide open is @ 200mm?
That's a tricky question to answer, because the focal lengths and max aperture reported to the camera jump suddenly between discrete values. In other words, there are discontinuities in the viewfinder numbers that don't exist for real, because in reality the focal length (and max aperture by extension) are infinitely variable.

But when the lens reports 190mm, the max aperture says f/4.5 (but it's likely not quite that open). When it reports 210mm, the max aperture says f/5.6 (but it's likely not quite that stopped down). You'll notice that the shutter speed doesn't really change between those settings, because the aperture didn't *actually* jump that much over a span of 20mm.

Based on spot metering the same subject at the short end and the long end—and assuming you can believe the f/4 and f/5.8 numbers as those limits—the metering at 200mm makes it appear that the true max aperture is right about f/5.0. (In other words, meter the same subject at 55mm, f/4 and note the shutter speed. Now move to 200mm and see that the shutter is 2/3 stop lower)

But that's just based on some seriously non-scientific messing around.
09-27-2009, 03:13 PM   #36
Senior Member
wowtip's Avatar

Join Date: Nov 2006
Location: West coast
Photos: Gallery
Posts: 254
Thanks guys! Ok, it is not easy to say, but somewhere around f5, which would make it slightly faster @ 200mm than the 50-200. Not that much faster that it would make much practical difference, though.

Hmm, well it might, if the 50-200 steps up from 4.5 to 5.6 much earlier than 190 mm.
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!
55-300mm, k-mount, pentax lens, post, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Your latest acquisition Perrumpo General Talk 10787 6 Hours Ago 01:00 AM
New acquisition Marlboroman Pentax SLR Lens Discussion 7 09-10-2010 11:07 AM
Recent Acquisition Damian Pentax SLR Lens Discussion 23 09-10-2010 10:07 AM
Suggestions on flash acquisition Whatabirdie Pentax DSLR Discussion 1 06-23-2008 07:41 PM
Lens Acquisition KFrog Pentax SLR Lens Discussion 11 01-23-2007 08:18 PM



All times are GMT -7. The time now is 07:38 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