Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version 38 Likes Search this Thread
02-08-2012, 12:40 PM   #151
Veteran Member
Chex's Avatar

Join Date: Feb 2011
Location: The 'Stoke, British Columbia
Photos: Gallery
Posts: 1,678
QuoteOriginally posted by Vylen Quote
If this lens is WR with a DC motor, I would love to get my hands on it. Although I dont know what I would do with it
Exactly my thoughts.. but I know what I'd do with it! I love the DC AF motor in the 18-135.. silent and fast, WR can't be that expensive to add in to a lens, look how cheap the kit 18-55 & 50-200 WR's are...
I'd love to see this be a "DA 550mm or 560mm f5.6 WR" lens with a DC motor (probably looking at what a 67-77mm filter thread?).

02-08-2012, 12:54 PM   #152
Veteran Member




Join Date: Feb 2011
Posts: 4,873
Original Poster
300 f/4 is 77mm. It's going to be bigger if there's a front filter at all.
02-08-2012, 02:13 PM   #153
Veteran Member
eddie1960's Avatar

Join Date: Aug 2010
Location: Toronto
Photos: Gallery | Albums
Posts: 13,667
QuoteOriginally posted by ElJamoquio Quote
300 f/4 is 77mm. It's going to be bigger if there's a front filter at all.
probably a drop in filter. I can't think of a modern lens this big that doesn't use drop ins at the back. a front filter with a close to 100mm filet size would be prohibitively expensive particularly for a lens targeted to sell for a lower price (less of a big issue if you are buying a 13000 euro for the built to order sony G 500 f4.0
02-08-2012, 02:47 PM   #154
Veteran Member




Join Date: Feb 2011
Posts: 4,873
Original Poster
QuoteOriginally posted by eddie1960 Quote
probably a drop in filter. I can't think of a modern lens this big that doesn't use drop ins at the back. a front filter with a close to 100mm filet size would be prohibitively expensive particularly for a lens targeted to sell for a lower price (less of a big issue if you are buying a 13000 euro for the built to order sony G 500 f4.0
Yup, earlier in this thread I mentioned that I thought the rear knurling was for the drop in filter that appears to be pictured behind the knurling. Some big lenses have both though. I think the Sigma 300 f/2.8 has a 112mm front filter in addition to the rear 46mm? So our 560 f5.6 could be slightly smaller but not a whole bunch smaller; definitely in the range of 100mm.

02-08-2012, 03:00 PM   #155
m8o
Veteran Member
m8o's Avatar

Join Date: Jul 2007
Location: 40°-55'-44" N / 73°-24'-07" W [on LI]
Photos: Gallery | Albums
Posts: 3,092
QuoteOriginally posted by ElJamoquio Quote
I think the Sigma 300 f/2.8 has a 112mm front filter in addition to the rear 46mm?
Unless that is brand new to their newest refresh of the lens, no it does not have a front filter.
02-08-2012, 03:46 PM   #156
Pentaxian
Mistral75's Avatar

Join Date: Feb 2009
Location: Paris, France
Posts: 7,527
The diameter of the front lens of a 560mm f/5.6 lens is necessarily bigger than or at least equal to 100mm.
02-08-2012, 04:31 PM   #157
Site Supporter
Site Supporter
jpzk's Avatar

Join Date: Jan 2009
Location: Québec
Photos: Gallery | Albums
Posts: 8,251
QuoteOriginally posted by Chex Quote
Exactly my thoughts.. but I know what I'd do with it! I love the DC AF motor in the 18-135.. silent and fast, WR can't be that expensive to add in to a lens, look how cheap the kit 18-55 & 50-200 WR's are...
I'd love to see this be a "DA 550mm or 560mm f5.6 WR" lens with a DC motor (probably looking at what a 67-77mm filter thread?).
According to this:
SMC Pentax-DA 560mm F5.6 Reviews - DA Prime Lenses - Pentax Lens Reviews & Lens Database

the lens is screwdriven, has Quick-Shift, and it doesn't state whether it is WR or not ... most likely NOT.

Can someone tell me: that large "tube extension" protruding at the front of the lens: is it the hood itself? Because, it sure looks like a very long lens overall.

Now, some of you here mention about an insertable filter ... what does it do to the IQ of a lens and why would need to insert a filter at all?
I know that some larger lenses do have this feature, but I really never understood why this would be a required thing.

Cheers.

JP

02-08-2012, 04:49 PM   #158
Site Supporter
Site Supporter
crewl1's Avatar

Join Date: Jul 2010
Location: Los Angeles, CA
Photos: Gallery | Albums
Posts: 9,807
QuoteOriginally posted by jpzk Quote
the lens is screwdriven,
Hmm wonder what the switch is for then if not to turn the motor on /off?
02-08-2012, 04:51 PM   #159
Veteran Member
audiobomber's Avatar

Join Date: May 2008
Location: Sudbury, Ontario
Photos: Albums
Posts: 6,806
> This lens is designed for the APS-C sensor format.

I wonder where this came from? Has Pentax stated that somewhere?
02-08-2012, 04:54 PM   #160
Veteran Member
demp10's Avatar

Join Date: Jun 2011
Location: Atlanta
Photos: Albums
Posts: 602
QuoteOriginally posted by jpzk Quote
Now, some of you here mention about an insertable filter ... what does it do to the IQ of a lens and why would need to insert a filter at all?
I know that some larger lenses do have this feature, but I really never understood why this would be a required thing.
Good lens design takes into account the extra piece of glass that is the rear filter, which among other things will affect focusing. Most lenses with this feature are shipped with a clear glass to be in place all the times when a filter is not used.
02-08-2012, 04:57 PM   #161
Site Supporter
Site Supporter
jpzk's Avatar

Join Date: Jan 2009
Location: Québec
Photos: Gallery | Albums
Posts: 8,251
QuoteOriginally posted by crewl1 Quote
Hmm wonder what the switch is for then if not to turn the motor on /off?
Looks like it could just be the AF/MF switch ???

I am just really guessing here.

JP
02-08-2012, 05:01 PM   #162
Site Supporter
Site Supporter
jpzk's Avatar

Join Date: Jan 2009
Location: Québec
Photos: Gallery | Albums
Posts: 8,251
QuoteOriginally posted by demp10 Quote
Good lens design takes into account the extra piece of glass that is the rear filter, which among other things will affect focusing. Most lenses with this feature are shipped with a clear glass to be in place all the times when a filter is not used.
Thanks for the reply, demp.

So, pretty much all larger "super" telephoto lenses would have this feature?

I am not into optics/physics, but how would this affect focusing?
The only think I remember reading about this was, a while back, a member of this forum acuired a FA*400/2.8 ... he had a tough time at first with the focusing until he was pointed to this specific "piece of glass" (the rear filter) that had to be inserted, which he did. Of course, he had good results with the lens afterward.

I still don't undertsand the concept though.

JP
02-08-2012, 05:02 PM   #163
Site Supporter
Site Supporter
jpzk's Avatar

Join Date: Jan 2009
Location: Québec
Photos: Gallery | Albums
Posts: 8,251
QuoteOriginally posted by audiobomber Quote
> This lens is designed for the APS-C sensor format.

I wonder where this came from? Has Pentax stated that somewhere?
I have no idea where this is coming from ... I just saw the link and pointed it out.

JP
02-08-2012, 05:03 PM   #164
Site Supporter
Site Supporter
jpzk's Avatar

Join Date: Jan 2009
Location: Québec
Photos: Gallery | Albums
Posts: 8,251
QuoteOriginally posted by Chex Quote
Exactly my thoughts.. but I know what I'd do with it! I love the DC AF motor in the 18-135.. silent and fast, WR can't be that expensive to add in to a lens, look how cheap the kit 18-55 & 50-200 WR's are...
I'd love to see this be a "DA 550mm or 560mm f5.6 WR" lens with a DC motor (probably looking at what a 67-77mm filter thread?).
Seems like there is no WR on that lens ...

JP
02-08-2012, 05:18 PM   #165
Site Supporter
Site Supporter
crewl1's Avatar

Join Date: Jul 2010
Location: Los Angeles, CA
Photos: Gallery | Albums
Posts: 9,807
" The current time and date in Japan is 9:17 AM
Thursday, February 09, 2012"

I guess we will know more shortly!
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!
500mm, lens, pentax 560mm, pentax news, pentax rumors

Similar Threads
Thread Thread Starter Forum Replies Last Post
DA 50mm, DA 560mm, D-FA 645 90mm to be revealed at CP+ Adam Pentax SLR Lens Discussion 56 02-10-2012 08:56 AM
Leitz 560mm f/6.8 Telyt-R - first shots and impression Piotr Pentax SLR Lens Discussion 1 05-11-2009 02:42 AM



All times are GMT -7. The time now is 03:47 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