Protection of Front Element on Nikon 800 mm PF in Certain Conditions

[BillW]

I got my 800 mm PF last month and have been enjoying using it. I have added a Zemlin lens cap which I like a lot more than the soft hood that came with the lens for everyday use and travel. I also got a two piece Zemlin lens hood that will be a bit more compact for travel and is a bit easier to mount.

One question — the original lens hood and the Zemlin lens hood give a lot of protection to the front element. I have felt comfortable with that in regular shooting. But I am more concerned when shooting near saltwater and where these is blowing dust or sand. Normally, I might add a good quality clear filter there for protection. Note — I’m not trying to start a general debate over using clear filters.

Do 800 mm PF owners think additional protection is needed for salt spray? Or can you just carefully clean it off (and maybe that does not mean cleaning the lens periodically in the field with a microfiber cloth)? And what would be the best way to do that?

Sand seems possibly more problematic.

I noticed a thread on DPReview that mentioned a clear Kase filter designed to be used at the front of the 800 mm PF lens for protection. I did not see the filter on Kase’s US website, which made me wonder if it was for real. Saw a couple for sale on EBay for high prices.

Has anyone here seen such a Kase filter? Anyone with experience trying it out — wondering about impact on optical quality. Finally, curious if anyone has seen a dealer or Kase selling it (i.e., something other than EBay).

 

[Warren D]

If the 800 pf is like the other exotics, the front element is sacrificial, meaning that it is relatively easy to replace if damaged. The modern coatings do a very good job of shedding crud and are very resistant to scratches. Having been on hundreds of whale watches, I dealt with salt spray on a regular basis. The best approach is to wipe off salt water before it dries and leaves a residual crust. If that happens, I'd use a wet (more than damp but not dripping) clean cotton cloth and lightly blot the salt crystals until they were dissolved and then remove by wiping with another clean cloth. I'd finish with my usual lens cleaner, Formula MC. This was before the current batch of better coatings and I never had a scratch in any of my lenses. The new coatings almost seem to repel dust and dirt, I was in a dusty environment a few days ago, got home and looked at my lenses and they are spotless!
As for blowing sand, anything you put in front of the lens will degrade the image, the 800 pf has high precision glass. I'd be making a decision based on how bad I want or need to shoot in those conditions, maybe try shooting with the wind.

 

[agrumpyoldsod]

Has anyone here seen such a Kase filter? Anyone with experience trying it out — wondering about impact on optical quality. Finally, curious if anyone has seen a dealer or Kase selling it (i.e., something other than EBay).

Images of this (a UV filter) are posted on another web site but I could not see it on the Kase website so I am guessing the person was provided a copy to try. He would not INITIALLY respond to my enquiries w.r.t sourcing -- but followed up with "Form my dealer in Beijing." SEE
I certainly DO NOT intend to put anything in front of my 800 or 400 when shooting -- never did with my f-mount long glass won't with the z mount versions. The Zemline lens caps are great though.

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[IainD]

Andy, is there any chance the spring inside the Zemlin can could scratch the lens front element?

 

[Kip Cotter]

Andy, is there any chance the spring inside the Zemlin can could scratch the lens front element?

Message from Karl, fwiw, as a response to my inquiry on a video. I love the lens cap and don't personally have concerns with it.

Kip Cotter​

2 months ago
I saw some chatter on the lens cap awhile back. Any concern that the Spring steel pieces inside the cap could come out and harm the front element? I’m not sure if the design has them retained so this could never happen?

https://accounts.google.com/Service...p&hl=en&next=%2Fwatch%3Fv%3DfWWqyPSL0bQ&hl=en

kzemlin​

2 months ago (edited)
While they are visible, the spring wires are fully captured in the cap. I have to insert the stainless steel spring wires in from the side. You need to pry the wire out of the groove or use pliers to remove it. The groove is open on the bottom to facilitate the 3D printing process. All the contact faces in the cap against the wire are angled to direct the wire away from the lens. The cap is also extremely strong. I tested my largest cap by supporting it only the rim and standing on a small plug in the center with my full weight (225 LB at the time). The cap deflected less than 1mm and there were no signs of failure in the cap - no cracking, no damage, no impact on fit or function. Also, thanks for your order!

 

[IainD]

Thank you Kip. That answers my question
(I once had a Hoya professional filter that came unsprung and the sharp end of the spring was resting on the front element of my 24-70 f2.8. Caused me some concern, but obviously fixed in the Zeal.
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