Loose Built-in Hood -- Pentax-A 100 F3.5

*Stratario* · 07-25-2009, 08:29 AM

I got a nice Pentax-A 100mm F3.5 of eBay. It's in excellent condition optically and cosmetically. However, the built in lens-hood is very loose. It slides back and forth easily by itself when the lens is tilted to a slight angle. Any suggestions on how I should deal with this? Thanks is advance.

**Marc Sabatella** · 07-25-2009, 12:51 PM

Are you sure it's f/3.5? I'm not aware of any such lens. There's an f/2.8, and there f/2.8 and f/4 macros. The non-macro f/2.8 is optically the same as the M100/2.8 that I have; I only *wish* mine had a hood!

Anyhow, I've got a couple of lenses with those built in hoods that are slightly dented and they kind of "catch" a bit sliding in and out. I'm not sure what normally dampens the motion, but the slight dent seems to help, actually. Not sure if you want to go so far as to intentionlly dent your hood, but could be worth a shot if no other alternatives present themselves.

GerryL · 07-25-2009, 03:45 PM

I also have a similar lens but not a Pentax branded one.
I was tempted to disassemble the hood just to see what mechanism it has to make it a bit tight gripping.
I forgot it after a while and at one time I almost forced the hood off the lens just to make some sort of an adjustment.
I hope someone here knows about hoods like these and have actually repaired them.
I also need this fix.

*gofour3* · 07-25-2009, 05:52 PM

I had a K300/4 with a loose built in hood. I sent it to Eric to fix.

*Stratario* · 07-25-2009, 06:25 PM

Originally Posted by Marc Sabatella

Are you sure it's f/3.5? I'm not aware of any such lens. There's an f/2.8, and there f/2.8 and f/4 macros. The non-macro f/2.8 is optically the same as the M100/2.8 that I have; I only *wish* mine had a hood!

Anyhow, I've got a couple of lenses with those built in hoods that are slightly dented and they kind of "catch" a bit sliding in and out. I'm not sure what normally dampens the motion, but the slight dent seems to help, actually. Not sure if you want to go so far as to intentionlly dent your hood, but could be worth a shot if no other alternatives present themselves.

You're right Marc. I got it confused with my ProMaster 100mm F3.5 macro. The lens that has the problem is a Pentax-A 100mm F2.8 and it's not Macro.

Just1MoreDave · 07-25-2009, 07:35 PM

The hoods I've seen (unfortunately not on your lens) use thin felt to provide friction, like the old metal lens caps. I think to get the hood off and replace the felt, you'd have to remove the trim ring around the front element and unscrew the three screws which hold the barrel with the filter threads on. Take that barrel off and the hood should come with it, and you can slide the hood off. On a Pentax-M lens, the trim rings unscrew using the filter threads. On Pentax-A lenses, some unscrew, some pop off, some are even glued on.

*Stratario* · 07-26-2009, 07:41 AM

Originally Posted by Just1MoreDave

The hoods I've seen (unfortunately not on your lens) use thin felt to provide friction, like the old metal lens caps. I think to get the hood off and replace the felt, you'd have to remove the trim ring around the front element and unscrew the three screws which hold the barrel with the filter threads on. Take that barrel off and the hood should come with it, and you can slide the hood off. On a Pentax-M lens, the trim rings unscrew using the filter threads. On Pentax-A lenses, some unscrew, some pop off, some are even glued on.

Thanks for the tip(s) Dave. I'll have a close look to see if I can get to the hood.

*Stratario* · 07-26-2009, 07:42 AM

Originally Posted by gofour3

I had a K300/4 with a loose built in hood. I sent it to Eric to fix.

Can you please pm me with the information on how to contact Eric, just in case I can't fix it myself? Thanks.

Just1MoreDave · 07-28-2009, 11:57 AM

I might have been wrong about how to take this lens apart. See this thread about the Pentax-M 135mm f3.5:

Taking apart an SMC M 135/3.5

And here is Eric's site:

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