Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version 4 Likes Search this Thread
05-09-2013, 01:39 PM   #31
Site Supporter
Site Supporter
LaurenOE's Avatar

Join Date: Sep 2009
Location: Back in Florida, but worldwide gigs!
Photos: Albums
Posts: 3,690
Original Poster

Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here.


QuoteOriginally posted by crewl1 Quote
I'm using this hood configuration recommended by Soldbear
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/217453-dfa100w...ml#post2301437


Works great and makes a more compact unit. If you go this route let me know and i can send you an extra cap i have.
I looked for some threads, but I don't see why that works?
Vignetting?
It looks cool, but??????

05-09-2013, 01:52 PM   #32
Site Supporter
Site Supporter
crewl1's Avatar

Join Date: Jul 2010
Location: Los Angeles, CA
Photos: Gallery | Albums
Posts: 9,807
I'll see if I can find the discussion.
I had the same reservations about vignetting as well but as SOldbear indicated there is none due to the 100mm focal length and AF-C application.
I proved it to myself when I tried it.
Main advantage for me is the lens is same shape with hood on as off, is always protected, and is short when at infinity.
05-09-2013, 01:57 PM   #33
Site Supporter
Site Supporter
LaurenOE's Avatar

Join Date: Sep 2009
Location: Back in Florida, but worldwide gigs!
Photos: Albums
Posts: 3,690
Original Poster
QuoteOriginally posted by crewl1 Quote
I'll see if I can find the discussion.
I had the same reservations about vignetting as well but as SOldbear indicated there is none due to the 100mm focal length and AF-C application.
I proved it to myself when I tried it.
Main advantage for me is the lens is same shape with hood on as off, is always protected, and is short when at infinity.
Ok, sounds like a plan. I'll try it!
Where to buy a -quality - step-down ring?
Recommendations?
05-09-2013, 02:04 PM   #34
Site Supporter
Site Supporter
crewl1's Avatar

Join Date: Jul 2010
Location: Los Angeles, CA
Photos: Gallery | Albums
Posts: 9,807
I meant aps-c, not AF-c duh.

Step down ring is 49-28 mm. I used generic ebay type.
http://bit.ly/10JfrsW

05-09-2013, 02:25 PM   #35
Site Supporter
Site Supporter
LaurenOE's Avatar

Join Date: Sep 2009
Location: Back in Florida, but worldwide gigs!
Photos: Albums
Posts: 3,690
Original Poster
QuoteOriginally posted by crewl1 Quote
I meant aps-c, not AF-c duh.

Step down ring is 49-28 mm. I used generic ebay type.
http://bit.ly/10JfrsW
Cool. Just ordered one.
05-09-2013, 02:36 PM   #36
Loyal Site Supporter
Loyal Site Supporter
pacerr's Avatar

Join Date: Jan 2008
Location: Paris, TN
Photos: Gallery | Albums
Posts: 3,349
Find an old, screw-in filter ring of the correct diameter with a removable retainer ring. Heck, just cut out a circle of dark paper with a hole in it and hold it over a UV filter to get the right size. Experiment with cardboard to find a hole diameter that doesn't vignette. Make up a more permanent aperture disk to suit.

Total cost: insignificant if you have a suitable filter; a $1 or two if you havve to acquire an old color filter on fleabay.

Hood selection's easy. No math or magic required. Just wrap paper around the lens and extend the tube until vignetting occurs at the FL of interest. Use that length to define the hood you need - or make yourself.

You'd be surprised what works from a practical standpoint. I'd guess about 1/3 that length for the 100mm lens as that's on a 300mm. The APS-C field-of-view makes most FF and tulip hoods (especially those for wide zooms) almost useless - unless you 'up-grade' to a longer FL.

(Besides, DIY hoods are about all light beer's good for anyway! )

H2
Attached Images
View Picture EXIF
PENTAX K-5  Photo 
05-09-2013, 02:37 PM   #37
Site Supporter
Site Supporter
LaurenOE's Avatar

Join Date: Sep 2009
Location: Back in Florida, but worldwide gigs!
Photos: Albums
Posts: 3,690
Original Poster
QuoteOriginally posted by pacerr Quote
Find an old, screw-in filter ring of the correct diameter with a removable retainer ring. Heck, just cut out a circle of dark paper with a hole in it and hold it over a UV filter to get the right size. Experiment with cardboard to find a hole diameter that doesn't vignette. Make up a more permanent aperture disk to suit.

Total cost: insignificant if you have a suitable filter; a $1 or two if you havve to acquire an old color filter on fleabay.

Hood selection's easy. No math or magic required. Just wrap paper around the lens and extend the tube until vignetting occurs at the FL of interest. Use that length to define the hood you need - or make yourself.

You'd be surprised what works from a practical standpoint. I'd guess about 1/3 that length for the 100mm lens as that's on a 300mm. The APS-C field-of-view makes most FF and tulip hoods (especially those for wide zooms) almost useless - unless you 'up-grade' to a longer FL.

(Besides, DIY hoods are about all light beer's good for anyway! )

H2
Nice!!!!!

05-09-2013, 05:12 PM   #38
Veteran Member




Join Date: Apr 2008
Location: Pittsburgh, PA
Photos: Gallery | Albums
Posts: 667
@pacerr what concerns me most about that is that someone actually drank Natural Light. The last time I had one of those was in college before I could buy myself a more satisifying drink.
05-09-2013, 06:30 PM   #39
Site Supporter
Site Supporter
LaurenOE's Avatar

Join Date: Sep 2009
Location: Back in Florida, but worldwide gigs!
Photos: Albums
Posts: 3,690
Original Poster
QuoteOriginally posted by Allison Quote
@pacerr what concerns me most about that is that someone actually drank Natural Light. The last time I had one of those was in college before I could buy myself a more satisifying drink.
LOL!!
05-09-2013, 07:13 PM   #40
Veteran Member




Join Date: Mar 2012
Location: Perrineville, NJ
Posts: 1,375
Doesn't that shiny beer can reflect a lot of light, internally? I'd think the lower concave portion would act like a big solar concentrator!
05-09-2013, 09:01 PM   #41
Veteran Member
cali92rs's Avatar

Join Date: May 2011
Location: Long Beach, CA
Posts: 3,354

05-09-2013, 09:03 PM   #42
Loyal Site Supporter
Loyal Site Supporter
pacerr's Avatar

Join Date: Jan 2008
Location: Paris, TN
Photos: Gallery | Albums
Posts: 3,349
Nope - flat black spray enamel in this case. In most light conditions a hood that long serves pretty well even without paint so long as you don't bore-sight a bright light.

Actually, that's one I keep around just to drive the gear purists nuts and/or 'break the ice' with a shy group.

And to make the point that you don't need to spend $40 on a plastic shell to shield a lens from stray light.

And to demonstrate how long an effective hood can be for tele lenses on APS-C sensors compared to FF. There's a lot of difference between the effect of axial light flare (which a hood doesn't affect) and off-axis, refracted light which subtly reduces contrast (which is what hoods are really for).

QuoteOriginally posted by Allison Quote
@pacerr what concerns me most about that is that someone actually drank Natural Light. The last time I had one of those was in college before I could buy myself a more satisifying drink.
DRINK THAT?! Of course not, Allison.

Anybody that would consume THAT stuff would likely steal sheep an' give Wally-mart wallet-sized prints as a mother's day gift too.

I got that by skinnin' road-kill for the pelt.

H2

Last edited by pacerr; 05-09-2013 at 09:33 PM.
05-09-2013, 09:03 PM   #43
Site Supporter
Site Supporter
LaurenOE's Avatar

Join Date: Sep 2009
Location: Back in Florida, but worldwide gigs!
Photos: Albums
Posts: 3,690
Original Poster
QuoteOriginally posted by cali92rs Quote
Nice!
05-10-2013, 07:19 AM   #44
Loyal Site Supporter
Loyal Site Supporter




Join Date: Mar 2009
Location: Gladys, Virginia
Photos: Gallery
Posts: 27,653
The nice thing about spring is that it is time to break this lens out again...

Half gone Dandelion.




The End of the Lilacs.


05-10-2013, 08:49 AM   #45
Site Supporter
Site Supporter
LaurenOE's Avatar

Join Date: Sep 2009
Location: Back in Florida, but worldwide gigs!
Photos: Albums
Posts: 3,690
Original Poster
QuoteOriginally posted by Rondec Quote
The nice thing about spring is that it is time to break this lens out again...

Half gone Dandelion.




The End of the Lilacs.


Sweeeeet!
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!
dfa 100mm f/2.8, k-mount, pentax lens, slr lens

Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: Pentax DFA 100mm f/2.8 (non-WR) loveisageless Sold Items 4 09-04-2012 09:11 AM
For Sale - Sold: Pentax DFA 100mm f/2.8 Macro WR hiep2503 Sold Items 4 06-29-2012 04:12 AM
For Sale - Sold: Pentax 100mm f/2.8 Macro WR DFA - shipped (CONUS) jeffnesh Sold Items 3 07-14-2011 12:47 PM
For Sale - Sold: Pentax DFA 100mm f/2.8 WR macro (AUS) (AUS) tasot Sold Items 7 05-25-2011 06:19 PM
DFA 100mm f/2.8 WR problem emr Pentax SLR Lens Discussion 7 08-28-2010 05:05 PM



All times are GMT -7. The time now is 01:08 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