[GeeEmm]

A poster here mentioned these, and I can't find a thread with users' experiences with them, drawbacks, etc., so here we are. There is one thread highlighting their potential for reducing the need for HSS in daylight fill flash, but I am more interested in their non-flash shooting, landscapes particularly sunrise/sunset type situations.

Clip Filter Series (for PENTAX APS-C / Full-Frame) | STC eShop?OPTICAL CO. LTD. is the link I have, there may be others out there too.

Before I drop my hard-earned on these, I'd appreciate knowing a bit more about them and their usefulness.

[stevebrot]

PF moderator @gatorguy has experience as an owner. With any luck they might check in.


Steve

[DeadJohn]

...landscapes particularly sunrise/sunset type situations...

I think you'll be better with front-mounted filters for landscapes. Clip-in filters are great for astrophotography and infrared, where one smaller (and therefore cheaper) in-camera filter can be used with multiple lens sizes. The types of filters you'll need for daytime landscapes, though, often need adjustments during use and should go in front of the lens.

1) Neutral density (ND, and not "graduated" that I'll cover below) can work as a clip-in. Go with a dark ND to slow the shutter a lot when the sun is in frame. Compose your shot, then hold a hat or other object to block the sun while still showing the ground. Press the shutter, let the camera collect light from the ground, then at the last moment include the sun in the exposure. You'll need lots of trial and error with this.

1a) Note that I do not like that filter technique, because it's finicky with exactly how you place the hat, and the filter adds more sun flaring/ghosts to the image. I go filterless and brighten shadows with software. Either underexpose a single shot and lift shadows later, or bracket shots with HDR processing. See sample photo at bottom of the message.

1b) ND filters do have other good uses and could be okay as a clip-in. You can smooth/blur moving objects on bright days, whether it's to emphasize water flow, or to hide people and cars moving through a scene.

2) Graduated neutral density (GND) filters darken only part of the frame to decrease brightness differences between the sky and ground. GND is usually rectangular and slides into a front adapter to adjust for composition. It would be impractical as a clip-in.

3) Circular polarizers (CPL) can help darken a blue sky, enhance colors, and decrease haze. They have to be rotated to adjust the effect, and are usually round filters screwed onto the front of the lens, making them very awkward as a clip-in. Note that CPL doesn't help much with the sun itself, just reflected light from the sun, so are more a general landscape filter than for your main sunrise/sunset use case.

*1a) Here's the bracketed HDR photo I mentioned above, no filter.

[gatorguy]

A poster here mentioned these, and I can't find a thread with users' experiences with them, drawbacks, etc., so here we are. There is one thread highlighting their potential for reducing the need for HSS in daylight fill flash, but I am more interested in their non-flash shooting, landscapes particularly sunrise/sunset type situations.

Clip Filter Series (for PENTAX APS-C / Full-Frame) | STC eShop?OPTICAL CO. LTD. is the link I have, there may be others out there too.

Before I drop my hard-earned on these, I'd appreciate knowing a bit more about them and their usefulness.

I've used several different ND types from NiSi 100mm slide-in's and Breakthrough round filters and the STC on-sensor. The NiSi's and Breakthroughs are both very color neutral, the STC less so but still a pretty mild color cast, very easy to handle in post.

Where the STC is particularly useful is for something like midday sun and a scenario where you may be using several different lenses, some of them not screw-in filter compatible anyway. Every lens you use becomes an ND-filtered one without the bother of toting a specific thread size or a bag of delicate slide-in's with a separate holder. Fast and simple. BTW, at least in my own photography it wouldn't replace the usefulness of the NiSi's/Breakthrough's for more planned static photos or timed shots using a single lens, but if I'm moving around with different lenses and at a fast pace it is SO much much more convenient and pleasant.

I've used the STC IR-cut ND16 a few times on afternoon street portrait work, one planned shoot that ran past noon, and a late-day beach shoot, and been very pleased with the results. I've been able to avoid setting up an AD600 with HSS for those shallow DoF shots, and it's a whole lot easier to work and move around with. Well worth the price in my view and I have no regrets at all. It's stays in my camera bag taking up almost no space, and I'd planned on adding the ND64 too so thanks for the reminder.

By the way, the same STC works on both my crop and full frame Pentax cameras in case anyone is curious.

[Gray]

Every lens you use becomes an ND-filtered one without the bother of toting a specific thread size or a bag of delicate slide-in's with a separate holder. Fast and simple.

I agree with gatorguy ^^^

I own and use the ND 16, 64 and 1000 filters and find them particularly useful on the Sigma 8-16, which is too bulbous for a filter thread.

[GeeEmm]

Thanks for those comments, most helpful. Front mount filters on the 15-30 (and 8-16 - somebody please buy mine!) are messy and damn expensive, and this is the incentive to try something like these because, as pointed out above, 'one size fits all' and the bulbous front element is a non-issue. But there are limitation, especially no CPL. I'll have to do some more thinking ...

[DeadJohn]

...Front mount filters on the 15-30...

The STC rear mount clip-in filter is unfortunately not a solution for the 15-30.

I was interested in their astrophotography clip-ins. The 15-30 was not in the list of compatible lenses, and I was curious whether there was a known problem or maybe the lens just wasn't tested yet. STC replied that there's vignetting when that lens is used with their clip-in filter.

[GeeEmm]

The DFA 24-70 isn't on that list either - thanks for highlighting that detail.

The shortest (D)FA lens there is the 28-105, the next being the 31LTD. That suggests that the vignetting is limited to the below 28mm range, and maybe their use behind a 24-70 would only be affected at the very short end, but it could also be more of a result of the relative positioning of the real element and the resultant light path to the sensor.

I wonder how much of a difference shooting in crop sensor mode would make to the vignetting of those lenses, I note that the Sigma 8-16 is on the 'OK' list.

[gatorguy]

The STC rear mount clip-in filter is unfortunately not a solution for the 15-30.

I was interested in their astrophotography clip-ins. The 15-30 was not in the list of compatible lenses, and I was curious whether there was a known problem or maybe the lens just wasn't tested yet. STC replied that there's vignetting when that lens is used with their clip-in filter.

With which body? They show the 10-17 Fisheye and both the 14 and 15mm Pentax as compatible lenses with no mention of vignetting, but not specifically clarifying it applies to both the APSC's and the K1. I do see they mention the K1 and long lenses like the *300 may experience some vignetting. It's nothing I've personally seen with my K-70 and any lens I've used with the STC so far, but I don't recall which lenses I've used with it.

[DeadJohn]

With which body? They show the 10-17 Fisheye and both the 14 and 15mm Pentax as compatible lenses with no mention of vignetting, but not specifically clarifying it applies to both the APSC's and the K1. I do see they mention the K1 and long lenses like the *300 may experience some vignetting. It's nothing I've personally seen with my K-70 and any lens I've used with the STC so far, but I don't recall which lenses I've used with it.

I think it's reasonable to assume STC tested lenses based on Pentax' stated frame sizes(*): full frame lenses get tested on a K-1, APS-C lenses on an APS-C body. You would need to ask STC to confirm, though, since my message to them was focused on the K-1 15-30 and K-1.


(*) There are some lenses that are in the APS-C "DA" series but ever since the K-1 came out have been commonly considered full frame compatible. Depending on how well STC knows Pentax, they may have tested those as either APS-C or full frame.

[groovy81]

I agree with gatorguy ^^^

I own and use the ND 16, 64 and 1000 filters and find them particularly useful on the Sigma 8-16, which is too bulbous for a filter thread.

I heard that their nd filters get very soft on the edges, especially with wide angle len (I also want it for the sigma 8-16mm), is that your experience with it?

[Alfred2898]

Question for the owners. Is anyone able to measure the dimensions of this clip-in filter? I wonder if it possible to 3D-print it and using with 1.25" filters.