[rptdc]

Pentax-DA 40mm F2.8 Limited

Does anyone use a 49mm polarizing filter (or any filter) with this, along with the lens hood?

[pathdoc]

I used to use protective UV/skylight filters on everything, but now I've started unsubscribing to that philosophy. Polarising filters are a thing for very specific purposes, but if you need one, you need one and never mind the lens.

[Kevin B123]

I have used one under the hood, and a 9 stop nd filter no problems.

[Alex645]

Pentax-DA 40mm F2.8 Limited

Does anyone use a 49mm polarizing filter (or any filter) with this, along with the lens hood?

Great question, and my answer is....not yet.

But if you think it through, here are the pros and cons:

a) 49mm polarizer with hood on top:
Pro: filter protected from finger prints and impact, more common size and more polarizer choices, filter better shaded with hood from flare
Con: harder to clean filter, focusing ring and polarizer ring in close proximity with a pancake lens...harder to twist filter without accidentally changing focus

b) 37mm 30.5mm polarizer with hood underneath:
Pro: easier to clean, easier to twist without accidentally changing focus, looks cool
Con: more potential for flare, filter more likely to get smudged or scratched

With that in mind, I'd opt for "a" but am looking forward to seeing what others have actually experienced.

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Last edited by Alex645; 12-05-2017 at 05:00 PM. Reason: incorrect filter size

[rptdc]

I have used one under the hood, and a 9 stop nd filter no problems.

Thank you!

---------- Post added 12-05-17 at 02:30 PM ----------

Great question, and my answer is....not yet.

But if you think it through, here are the pros and cons:

a) 49mm polarizer with hood on top:
Pro: filter protected from finger prints and impact, more common size and more polarizer choices, filter better shaded with hood from flare
Con: harder to clean filter, focusing ring and polarizer ring in close proximity with a pancake lens...harder to twist filter without accidentally changing focus

b) 37mm polarizer with hood underneath:
Pro: easier to clean, easier to twist without accidentally changing focus, looks cool
Con: more potential for flare, filter more likely to get smudged or scratched

With that in mind, I'd opt for "a" but am looking forward to seeing what others have actually experienced.

Hmmm. I never thought about a polarizer out on the hood thread.

I too think 'a' is the primary option. I was mainly concerned of vignetting if I would be moving the 'hood' out further from the lens. Sounds like Kevin B123 has tested this successfully.

Thank you.

[Alex645]

I was mainly concerned of vignetting if I would be moving the 'hood' out further from the lens. Sounds like Kevin B123 has tested this successfully.

Good point. I think f/2.8 and the pancake design prevents that from happening, although you can always test this yourself wide open with just a clear filter of a white wall.

If the 40mm was f/2 or less, then I'd be concerned.

[Pentax Syntax]

I use a 49 mm circular polarizer and a rubber hood. I only use the normal hood with no polarizer. The 49 mm rubber hoods work pretty well. If you get a wide angle version you can use on the DA 21 also or use the DA 40 on the K-1.

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Last edited by Pentax Syntax; 12-05-2017 at 02:05 PM.

[Pentax Syntax]

I have used one under the hood, and a 9 stop nd filter no problems.

I agree this configuration works on crop bodies with only the slightest bit of darkening of the corners wide open. On full frame (K-1) you really need to remove the hood though. I go with a rubber hood in that case.

[Paul the Sunman]

b) 37mm polarizer with hood underneath:

The outer thread on the DA 40 hood is 30.5 mm, not 37 mm. I have, but no longer use, a 30.5 mm UV filter which I fitted INSIDE the hood, so there was no danger of additional vignetting. (It will screw into the hood either inside or outside.)

This isn't so convenient for a polarising filter though.

[Madaboutpix]

The outer thread on the DA 40 hood is 30.5 mm, not 37 mm.

Er, the inner thread being 30.5mm, more likely? But we get the picture nonetheless, I guess.

[Saltwater Images]

I often use a Hoya Pro 49 mm polarizing filter or a B+W 49 mm variable filter on the HD DA 40. Screw the filter on the lens then screw the hood on the filter. No issues.

[Alex645]

The outer thread on the DA 40 hood is 30.5 mm, not 37 mm.

Correct, 30.5mm NOT 37mm for the inner thread.

I don't like the screw-in lens cap, so I just use a 35mm Fujifilm film canister cap. I corrected my earlier post, thanks!

[rptdc]

Good point. I think f/2.8 and the pancake design prevents that from happening, although you can always test this yourself wide open with just a clear filter of a white wall.

If the 40mm was f/2 or less, then I'd be concerned.

I am looking forward to trying this. ...I have the 40mm F2.8 Limited and even a 49mm UV filter....but no K70 camera body yet . The K70 should be coming this week.

---------- Post added 12-05-17 at 06:32 PM ----------

I often use a Hoya Pro 49 mm polarizing filter or a B+W 49 mm variable filter on the HD DA 40. Screw the filter on the lens then screw the hood on the filter. No issues.

Great! Thanks.