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05-09-2013, 01:39 PM   #31
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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
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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
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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
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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
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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
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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
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05-09-2013, 02:37 PM   #37
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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
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@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
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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
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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
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05-09-2013, 09:03 PM   #42
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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
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QuoteOriginally posted by cali92rs Quote
Nice!
05-10-2013, 07:19 AM   #44
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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
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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!
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