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Tim V
18-May-2018, 03:00
Hi guys,

I'm building up to a project where I plan to use my 8x10" camera with stacked Lee ND filters to make exposures over the course of an entire days worth of light.

Unfortunately I don't have my lenses in front of me to mention specifically their filter thread diameter (I've got a 210mm G-Claron dagor type, and 12" Goerz Dagor AM Opt. Co. non-gold dot/rim), but I'm wondering if people out there could advise on what filter holder systems they use on such lenses or similar? From memory, the filter thread on my G-Claron is quite small and, unless I'm mistaken, Lee don't seem to make an adaptor for diameters smaller than 43mm that is recommended for wide lenses (shorter than 24mm equiv. or lenses with large IC where movements are to be used.) Can't remember if the G-Claron is smaller or than or not... Anyway...

I have the Lee Universal Lens Hood with integrated holder and love it – have used it for years with my Linhof Techno setup – so am hoping to stick with that for use with the 8x10" stuff.

Anyone out there got advise on the above, or the logistics / pitfalls / considerations when making ultra long exposures with LF gear? I'm thinking the two biggest battles with be predicting reciprocity failure / exposure times, and unexpected light leaks.

Thanks in advance,

Tim

Tobias Key
18-May-2018, 05:33
I am dabbling with ND's too. I plumped for standardising on 77mm screw in filters and use step up rings as necessary, mainly because I have a Toyo compendium hood and a Lee filter holder doesn't fit into it very well. There are lot of videos online giving tips on using nd's with DSLRs and the main thing that they all seem to emphasise is blocking extraneous light entering between multiple stacked filters in square filter systems. Other than that the main thing I have been wary of is LF's greater vulnerability to vibration and wind and the possiblity of light leaks that only become apparent in long exposures. I wrap my camera in my darkcloth and use a bag bellows which I hope is less likely to have any small pinhole leaks.

I have only gone as far as the several minute mark and I had one exposure ruined because halfway through it a ferry passed 100 yards to my left and vibrated the hell out of the camera. I forgot to look behind me before making the shot. If you want to expose images for a whole day you are going to need to shield the camera against changes in the weather.

Would it make sense to pitch a tent and then set up the camera inside it so you were shielded from wind, rain or even excessive sun beating down on the camera or lenses?

Jim Jones
18-May-2018, 05:49
Rather than stack filters, consider using a single filter with appropriate density such as those used by astronomers for solar photography.

John Kasaian
18-May-2018, 08:19
For years I got by with 4x4 Lee filters, which I inserted in a Lee gel snap filter holder which used a thick rubber band(like what asparagus comes bundled in---learn to love asparagus if you don't already) to attach to unthreaded lenses as large as a 14" Commercial Ektar. It can stack up to four filters
https://www.amazon.com/Lee-Filters-Gel-Snap-Holder/dp/B00CK8ZNGG/ref=sr_1_29?ie=UTF8&qid=1526656418&sr=8-29&keywords=lee+filter+holder

It's cheap! It works! And it's cheap.
Besides you'll learn new ways for preparing asparagus---a win-win, right?

Doremus Scudder
18-May-2018, 08:52
Whatever filter system you come up with, make sure that it is light-tight around the outside edges. With such long exposures, any little bit of light sneaking in a crack or edge can cause more fogging than you'd like.

I second the idea to find one filter that will do the job. In any case, keep the number of filters you use to a minimum to keep stray light from having more surfaces to bounce around on.

As far as exposure goes: you'll likely have to do a lot of testing, but if you use a material that has a few stops of overexposure latitude, you'll at least have some leeway. Once you get out to six hours, a twelve-hour exposure is only one stop overexposed (less than that even, due to reciprocity failure). 24 hours would only be two stops. I print negs intentionally overexposed by two stops all the time with great results.

Development may have to be adjusted for long exposures as well, but that's another thread :)

Best,

Doremus

Drew Wiley
18-May-2018, 09:03
Expect some loss of sharpness with stacked filters, esp plastic ones.

cdavis324
18-May-2018, 17:45
Easiest thing to do is use a Lee gel snap and wratten filters inside the bellows. That way you don’t have to worry about flare from the filter.

If you really want to put filters in front of the lens, look into the wine country holder or something... unless you want to use a ton of tape.

Either way, black tape is your friend.

There was a Korean artist who made photographs that were a full day. I can’t remember his name, but he did a project with ice sculptures as well. He used welding filters inside the camera(from what I remember). It was at least 10 years ago that I saw it.


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Lachlan 717
18-May-2018, 18:15
You don’t need anything as “aggressive” as tape. A simple strip of black foam will do the same and it is reusable.

Just slide it in/over/between where required.

Mark Sampson
18-May-2018, 20:48
Wrap your camera as well. I once tried an all-day exposure with two 4.0 ND filters- it was completely fogged. Never went back to it- and the next year I found my bellows had a pinhole in it. I'm thinking light will find leaks in your camera that would never register during a normal exposure time.

RichSBV
18-May-2018, 22:00
It might just be simpler and easier to use a pinhole instead of a lens!

cdavis324
19-May-2018, 11:30
However you do it, you should seal every joint. Around the lensboard, bellows frames, film holder, removable back, holder light trap. I’ve never done anything in the range of what you’re talking about, but regularly do 1 hr exposures. I used to use a chamonix with wide angle bellows(the bellows material is completely light tight, btw), but always tape every joint - considering the time I put into each picture it seems like good insurance to me. I’ve yet to receive my new camera, but hope it’s as light tight! And I never covered the bellows/camera with a dark cloth - I’d be more worried about the vibration it could add(although would be a great solution in non-windy environments).

Vibration is another problem you’ll have - I use an aluminum gitzo 5 series with a majestic head and a couple sand bags for good measure...

Good luck!



You don’t need anything as “aggressive” as tape. A simple strip of black foam will do the same and it is reusable.

Just slide it in/over/between where required.




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Eric Woodbury
19-May-2018, 12:10
A nice tutorial at BH

https://www.bhphotovideo.com/explora/photography/hands-on-review/a-guide-to-neutral-density-filters

I wouldn't stack more than 2 filters, not only because of image quality, but they won't add the way you think they might.

If you are aware of a big disturbance approaching during exposure, you can put a black card in front of the lens to interrupt the exposure. However, unless the disturbance lasts a long time, you'll never see it.

Sounds like fun.

Tim V
19-May-2018, 14:12
Thanks all for the great replies!

I wasn't aware that there were alternatives to the Lee filters, and it's the first I've heard of ND filters used for astrophotography. Any tips on where to look for them? I'm guessing they're expensive?

I've never done made exposures anywhere near the length I mentioned either, hence it's a real mystery to me how I might go about it. I've come to wanting to do it for conceptual reasons more than anything, but I'm just as curious about the results on an aesthetic level as well.

Seems like I should try and avoid stacking filters. Lee do a ND4.5 / 15 stop in the Pro IRND line, but that won't be strong enough. It'll get me in the ballpark though, as once I compensate for reciprocity failure I'm getting towards 6 hours with a 100iso film like Ektar (if I'm being optimistic.) I don't mind over exposing a few stops, so maybe I'll be okay? I want to use colour film for this, and work with the cross curves etc to heighten the shifts of light.

I did assume that I'd need to take out sheers in a gaffer tape company... This is where my Kiwi ingenuity should come to the fore... I'm expecting a lot of hic ups along the way, but should be fun.

Keept the tips and thoughts coming!

Eric Woodbury
19-May-2018, 14:27
With color, won't there be a tricky color shift since the different layers have different reciprocity failures?

Here's 7.2

https://www.bhphotovideo.com/c/product/1370757-REG/formatt_hitech_fcu67circnd7_2_firecrest_ultra_67mm_neutral.html

I don't know the ND factor here

https://www.amazon.com/Solar-Filter-Telescopes-Binoculars-Cameras/dp/B00DS7S52W

Tim V
19-May-2018, 14:35
I've found a few that might be suitable...

Namely this one: LINK (Formatt Hitech 100 x 100mm Firecrest Ultra ND 5.4)

Anyone have experience with the Formatt brand filters of this level? They go all the way up to ND 7.2! I'm thinking that once compensating for shifts of light; soft light in the morning and fading light at the end of the day, a 18 stop / ND5.4 should be ample. If I were to be conservative and accept over exposure, the 16 stop / ND 4.8 might be good too. I'm basing this on setting the camera up, using 100ISO film and stopping down to f45 or f64. At exposures of this length, the negative effects of diffraction are the least of my worries...

Lee also make this 20 stop ND for solar photographer : LINK (https://www.bhphotovideo.com/c/product/1153798-REG/lee_filters_sw150sol_150x150_sw150_solar_stopper_filter.html)

What do the brain trust reckon? :cool:

T

Tim V
19-May-2018, 14:37
Thanks for the links.

Yes, I'm fine to work with those shifts as part of the process. Kind of like them in some instances, although accept it might get a bit funky when pushing the exposure that far.

I will try with BW film too, but I'm interested in emphasising the shifts of light with colour. I'm going to need to make friends with a top notch drum scan operator, I fear...

Thanks again,

Tim



With color, won't there be a tricky color shift since the different layers have different reciprocity failures?

neil poulsen
19-May-2018, 19:55
It might just be simpler and easier to use a pinhole instead of a lens!

If you use a pinhole, you'll need a center filter.

neil poulsen
19-May-2018, 19:57
Stacking can be problematic, with light reflecting between adjacent filters, etc. Consider putting one filter on front and another on the back of the lens.

cdavis324
20-May-2018, 05:51
You can’t really predict what will happen with long exposures - you just have to start trying. It doesn’t work to mathematically project reciprocity when you get past a few min. At some point the light hitting the film won’t be enough to record any image at all(in spite of what the math says). You may want to consider some type of pre- flash for the film, so you can make sure an image is recorded... especially if you’re using really dark filters. You have to have enough light hitting the film to get over the toe - otherwise it doesn’t matter how long the exposure is.

I would try starting with the darkest wratten filter you can find and then you have some data. It will probably surprise you and you can go from there.

Ektar is fairly tolerant to exposure variations, but portra will give another few stops... especially if scanning.

There’s no need for expensive IR filters for film - there are a lot of used non-IR filters out there with digital shooters switching over. You can even start with a welding filter which is approx 14 stops and green, but will give you an idea of what you’re getting in to for cheap.

Good luck!




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Drew Wiley
21-May-2018, 09:25
One thing you'll discover is that most ND filters aren't really neutral when it comes to fussy color applications. Some can be a bit greenish. And at exceptionally long exposures, you'll have other unwanted surprises. I strongly recommend doing a series of exposure tests with cheap 35mm film first.
Flashing is tricky. But you can do it employing a diffused warming filter to offset the tendency of Ektar to go unduly blue under such circumstances. Aim for a flashing exposure equivalent to Zone III against a blank neutral gray target.

Steven Ruttenberg
22-May-2018, 20:47
Formatt-Hitech has a 4x4 Fircrest Ultra that is 24 stops now. I use only F-H filters for my grad nds and nd filters. 24 stops, 100 iso, f/16 or f/22 and you will need a day or two to get an image. Stack it with a 2nd 24 stop and well... I also put the ND gasket on the holder and mount the filter up against that as well, no light leak there. I would also wrap a black out cloth over the entire camera just before you release the shutter. Do post up the picks when you get them

Steven Ruttenberg
22-May-2018, 21:02
You can also calculate the required exposure assuming linear response as exposure time no filter *2^n where n is the filter factor. Example, say for iso100. f/16 the required exposure time is 1/2 second, then 0.5*2^7.2 = 97 days. At 1/500 sec, = 9.3 hours. So, depending on your goal, a 24 stop may be way too much the 16 stop filter may work for 1/2 second = 9.1 hours. Using Tmax 100 would be like 18.2 hours if the reciprocity function holds where required exposure doubles for pretty much anything 1 minute and longer.

I love the F-H filters, they are truly neutral. Check out BWVision.com for one artist that uses them. Just be sure to seal up camera well prior to exposure.

Tim V
22-Jun-2018, 14:25
Hi all,

Great info above, thank you!

I'm wanting to use my 210mm G-Claron (Dagor type) for the long exposures, and am now trying to get the kit together. I want to put the filter behind the lens and within the bellows of the camera but have a few questions...

For those that know the Dagor type G-Claron 210mm, am I correct in thinking that the rear 'filter thread' is 36mm? I've tried to measure it with digital callipers, but I want to confirm before I commit to buying a threaded adaptor for a filter holder system. I know the outside of the rear barrel (if that's the correct term) measures 39mm, so think 36mm seems about right for the thread?

I'm thinking of using the Lee Seven5 system holder, with a 15 stop Pro IRND. I'll need to do something about light spillage out the sides of the filter if I go this way (gaffer tape?) but in principle it should work, although I'm suspicious with a rear lens element so small that the screw in filter holder adapter might introduce some vignetting...

Anyone able to speak to the above, either with regards to using filters with the G-Claron or otherwise?

Thanks again,

Tim

Lachlan 717
22-Jun-2018, 15:02
Or, you could just mount it on the front of the lens like 99.9999% of photographers do...

Bob Salomon
22-Jun-2018, 15:09
Yes, you can’t do that, however you will create a focus shift and reduce the resolution of the lens by just putting an immaculately clean filter behind the lens. Any defects in filter quality or dust, grease, fingerprints, etc. will further degrade the quality of a lens.

A good rule to follow is to never put a filter inside or behind a lens unless that filter is specifically designed by the lens manufacturer to be placed there!

cdavis324
22-Jun-2018, 15:09
Lee gel snaps are great for behind the lens, but not sure it’d work for anything that dense... gelatin filters are better for behind the lens because they are so thin you don’t really have to worry about focus shift.

In terms of tape, I use black artists tape because it’s thick enough to be opaque, and easy to remove. I’d be hesitant to use gaff tape because it’s so sticky.




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Drew Wiley
22-Jun-2018, 16:33
Why do people bother with a good lens and then spoil it all with either a cheap filter or one put behind the lens?

andrewch59
22-Jun-2018, 18:13
https://www.bwvision.com/complete-guide-long-exposure-photography-2016-edition/
Great exposure chart, I recommend the Format Hitech ND filters, I use the slimline screw-ons

cdavis324
23-Jun-2018, 04:44
Why do people bother with a good lens and then spoil it all with either a cheap filter or one put behind the lens?


Because “sharpness” isn’t the be all end all in photography!! Life(and photography) would be kinda boring if we were all after the same thing...[emoji6]

OP - are you trying to shoot inside or outside? I once tried an interior 24hr exposure with a welding filter - about 14 stops - and portra 400. The neg was very thin with no detail whatsoever in the shadows.

Can you report back once you get some data? It’s good to hear others successes and failures with pushing film to its limit!


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Tim V
23-Jun-2018, 12:43
I'm wanting to shoot outdoors, from dawn to dusk; entirety of a days worth of daylight hours.

By my estimation–and it's just that, an estimation–is that a 15 stop ND should do the trick with 400ISO film shot at f45 or 64, perhaps pulled a bit to control the contrast, although I'll do some tests first to confirm that. Will really depend on the light of the day. It's as much for conceptual as aesthetic reasons I want to do this, as I'm trying to build on a long term project that has increasingly become about the light at a particular location. Anyway, it might not work or it might work and not look interesting, but I want to give it a try.

The reason for putting the filter behind the lens was simply because so many people recommended it as a way to help avoid flare as well as light leaks getting in via oblique angles in the filter holder. It's a relatively extreme use case regardless of filter position. I didn't know that putting a filter behind the lens can cause focus shift. That will need to be something to consider. I already have and use a Lee Universal Lens hood with filter slots, perhaps I just start by using that and make sure I tape up the sides of the holder really well. Not sure if there's an adaptor that goes to a thread as small as my G-Claron has, or if a screw in filter holder will introduce vignetting, but there's only one way to find out...

Thanks,

Tim




Because “sharpness” isn’t the be all end all in photography!! Life(and photography) would be kinda boring if we were all after the same thing...[emoji6]

OP - are you trying to shoot inside or outside? I once tried an interior 24hr exposure with a welding filter - about 14 stops - and portra 400. The neg was very thin with no detail whatsoever in the shadows.

Can you report back once you get some data? It’s good to hear others successes and failures with pushing film to its limit!


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Bob Salomon
23-Jun-2018, 13:45
I'm wanting to shoot outdoors, from dawn to dusk; entirety of a days worth of daylight hours.

By my estimation–and it's just that, an estimation–is that a 15 stop ND should do the trick with 400ISO film shot at f45 or 64, perhaps pulled a bit to control the contrast, although I'll do some tests first to confirm that. Will really depend on the light of the day. It's as much for conceptual as aesthetic reasons I want to do this, as I'm trying to build on a long term project that has increasingly become about the light at a particular location. Anyway, it might not work or it might work and not look interesting, but I want to give it a try.

The reason for putting the filter behind the lens was simply because so many people recommended it as a way to help avoid flare as well as light leaks getting in via oblique angles in the filter holder. It's a relatively extreme use case regardless of filter position. I didn't know that putting a filter behind the lens can cause focus shift. That will need to be something to consider. I already have and use a Lee Universal Lens hood with filter slots, perhaps I just start by using that and make sure I tape up the sides of the holder really well. Not sure if there's an adaptor that goes to a thread as small as my G-Claron has, or if a screw in filter holder will introduce vignetting, but there's only one way to find out...

Thanks,

Tim

Are you trying to duplicate what Stephen Wilkes does?

cdavis324
23-Jun-2018, 15:56
Are you trying to duplicate what Stephen Wilkes does?

To me it sounds more like Atta Kim. He did a series of full day exposures about 10 years ago, and there’s some info on his technique out there.

At f64 or 45, you don’t really have to worry about focus shift... that being said, why not put the filter in front of lens first to try since you have what you need to do that?




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Bob Salomon
23-Jun-2018, 15:58
To me it sounds more like Atta Kim. He did a series of full day exposures about 10 years ago, and there’s some info on his technique out there.

At f64 or 45, you don’t really have to worry about focus shift... that being said, why not put the filter in front of lens first to try since you have what you need to do that?




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Wilkes does it all the time. Check his web site.

cdavis324
23-Jun-2018, 16:03
Wilkes does it all the time. Check his web site.

I’ll check it out - all I know if his is the day to night series...


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Drew Wiley
23-Jun-2018, 16:05
It's not just a problem of focus shift. Even stopped way down there's likely to be be an apparent drop in optimal image quality. I've tested for this. Of course, if this is the look you're after, so be it.

Tim V
23-Jun-2018, 16:13
Never heard of either of those photographers, will check them out...

Tim V
23-Jun-2018, 17:45
I like Atta Kim's urban landscapes, they are somewhat close to what I want to do, all be it with a different subject matter and intent. Not keen on Stephen Wilkes's work. Too manipulated for my tastes, at least the Day to Night series on his website is.
Thanks for the references. Appreciate them.
PS: Have ordered Atta Kim's book, On-Air: Eight Hours. Looking forward to seeing the images properly as the ones on the internet aren't very detailed.

Steven Ruttenberg
23-Jun-2018, 20:20
Here is my take, I shoot long exposure quite often, Outdoors is better situation for long exposure to remove pesky people from an image, blur clouds, and do all sorts of neat stuff, especially if going black and white or shooting color and converting. Using the format filter system get I would say a 10 stop to start with, and a 5 stop. Make sure to install the gasket on the filter holder (using the 4x4 system which is most versatile) If you don't use the gasket, you will get reflections of the front of the lens on the image, also, be sure to wrap the camera in a dark clot or something that will seal out the light. Wrap it 360, and front to back. Don''t try to adjust focus once you start. Be prepared to be with your camera for a couple of days at worst, a couple of hours at best. Err on the side of slight over exposure too. Good luck. Best part is you don't have to deal with the digital noise and whether cold or hot won't effect the smoothness of the image. With digital, even if it is freezing outside, without a thermal cooler and even with you get all kinds of noise from dark, bias, hot pixels, etc. The hotter it is outside, the longer the exposure the worse it becomes to the point you will not get a useable image regardless of post-processing techniques. Why I love film for long exposure.

Tim V
24-Jun-2018, 00:10
I use a Leaf Credo 60 on a Linhof Techno platform. Great setup, but it’s crap with exposures longer than 30 secs, and especially bad shooting backlit scenes. It’s way better for many things, but when it’s not used in good conditions things fall apart really quickly. I love film for the latitude, mostly, plus the way it forces me to be more disciplined and mentally present.

Tim V
24-Jun-2018, 00:20
Thanks for the advise! Much appreciated. I want to start my exposure just before sunrise, and end it just after dusk. I also want to simply accept the cross curves - well, at least to a certain extent - and let reciprocity work in my favour. I don’t have a gasket for my Lee system, so thanks for the tip.


Here is my take, I shoot long exposure quite often, Outdoors is better situation for long exposure to remove pesky people from an image, blur clouds, and do all sorts of neat stuff, especially if going black and white or shooting color and converting. Using the format filter system get I would say a 10 stop to start with, and a 5 stop. Make sure to install the gasket on the filter holder (using the 4x4 system which is most versatile) If you don't use the gasket, you will get reflections of the front of the lens on the image, also, be sure to wrap the camera in a dark clot or something that will seal out the light. Wrap it 360, and front to back. Don''t try to adjust focus once you start. Be prepared to be with your camera for a couple of days at worst, a couple of hours at best. Err on the side of slight over exposure too. Good luck. Best part is you don't have to deal with the digital noise and whether cold or hot won't effect the smoothness of the image. With digital, even if it is freezing outside, without a thermal cooler and even with you get all kinds of noise from dark, bias, hot pixels, etc. The hotter it is outside, the longer the exposure the worse it becomes to the point you will not get a useable image regardless of post-processing techniques. Why I love film for long exposure.

Ted R
24-Jun-2018, 10:22
Perhaps you are already aware of this, and perhaps this has been covered already however I didn't see it.

High value ND filters show a problem when used with digital cameras, the filter performs as expected in the visible range but not beyond the visible range at both ends there is significant leakage. Unwanted and unpredictable color shifts occur due to sensor sensitivity beyond the visual range, especially the infra-red, unless additional band-stop filters are added. Filter maker BW makes a statement about this on their website, in the detail spec for filter families. In your film application there may be a similar effect. Might be a good idea to test for this.

Steven Ruttenberg
24-Jun-2018, 18:13
Perhaps you are already aware of this, and perhaps this has been covered already however I didn't see it.

High value ND filters show a problem when used with digital cameras, the filter performs as expected in the visible range but not beyond the visible range at both ends there is significant leakage. Unwanted and unpredictable color shifts occur due to sensor sensitivity beyond the visual range, especially the infra-red, unless additional band-stop filters are added. Filter maker BW makes a statement about this on their website, in the detail spec for filter families. In your film application there may be a similar effect. Might be a good idea to test for this.

This is why I use the Formatt-Hitec filters. They literally have no color cast at all, I do mean none. I have been using them for a very long time with no problems. The problem you get is not using the gasket between the filter and the holder as well as ensuring your camera is completely sealed from any light leakage. I have a custom set up for my 5DMKIII to prevent light from getting in anywhere. If you don't you get streaks, color shift, etc. If you have a filter that is poor IRND, you will get a green cast, soft blacks due to IR contamination etc. Make sure for long exposure you get the best filter you can afford and I recommend the Formatt filters. Especially the Ultra that they just came out with. For film, IR should not be an issue since most films are not sensitive to the IR range like a digital sensor is. Even with its IRND hot mirror installed by the factory. Given enough exposure time and bright enough sun light, you can get some IR contamination which is practically unrepaireable.

Tim V
30-Jul-2018, 04:25
Out of curiosity, does anyone know if the Formatt Fiercrest filters fit in the Lee holders? Both seem to be made out of 2mm thick glass. Wondering if the gasket on the Firecrest would fit on the filter when in the Lee holder...

I ask this because by my own calculations, for what I would like to do, it seems a 13 stop ND filter would be the best bet. The Lee 15 stop IRND would seem to be too strong after compensating for reciprocity and light level changes over the course of a day. I already have the Lee Universal hood, so it seems natural to find a way to use that so I don't need to shell out another $160+ for the Formatt holder.

Or I could simply use a 58mm circular filter with a 40.5-58mm step up ring (for use with my Dagor type 210mm G-Claron) and dispense with the hood altogether, flare be damned... That'd be the cheapest option by far with the best quality filter.

For all of the above options however, I do worry slightly about vignetting potentially caused by the step up ring, be that to attach a circular filter or the Lee hood.