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01-01-2016, 02:41 PM   #1
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My ND filter situation

I have a Vivitar 28mm f2 close focusing lens. Nice lens. I'm pretty happy with it. Except..... in bright sunlight I can't open it up. At 100 ISO with a CPL filter the only way I can get shutter speeds less than the 1/1000 is to stop down all the way. f16 is pretty much it. Opening 2 or 3 stops and it will overexpose. Ideally, I'd like to use the lens for outdoor cars shows. There's always some Bozo who will walk into the frame and I hope to be able to use a tripod and long exposures to get rid of them. You can't wait them out, they're lined up waiting for a chance to walk in front of you. So, I'm looking at ND filters and hope to lean on your wisdom. Stacking on the 28mm might create some vignetting problems. The Cokin system has the potential for light leaks and potential damage to the filters while moving around. Are variable filters as bad as some people say or are the problems operator error? I'd like to do at least 30 second exposures but I don't know if the variable filters will darken enough for that. Ideas? Suggestions? (Other than "Quit sniveling about a lens that's too fast.") Thanks for your input!

01-01-2016, 03:08 PM   #2
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I would say the screw on ones might be better for your application, but you might get some vignetting. If you do, just frame a bit wider and crop in post. And you might not get any vignetting anyway.

ND filters are rated in a number of ways. You might see ND2 or 1X or .3ND but all mean a one stop reduction.

In your case take the shutter speed you get in sunlight with that lens wide open and then the shutter speed you want and then calculate the number of stops difference that would be. So if you are at 1/1000 and want to be at 30 seconds that is I think 15 stops. Which you are not going to get with an ND filter. 8 to 10 stops is the best you can expect.

So to achieve your goal you might want to look at 10 stop ND filters and then stop down enough to get your shutter speed to 30 seconds.

---------- Post added 01-01-16 at 02:12 PM ----------

Some additional info:
Best 9 and 10-stop ND filters - Amateur Photographer
10 Stop Neutral Density Filter Review
01-01-2016, 03:21 PM   #3
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Or you can use a tripod and take multiple exposures over several minutes as the people move around, then combine them. Gimp will do it by using layers and tapering the opacity in a 1, 1/2, 1/3 ... sequence. Other editors may have a more automated method.
01-01-2016, 03:44 PM   #4
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QuoteOriginally posted by gifthorse Quote
I have a Vivitar 28mm f2 close focusing lens. Nice lens. I'm pretty happy with it. Except..... in bright sunlight I can't open it up. At 100 ISO with a CPL filter the only way I can get shutter speeds less than the 1/1000 is to stop down all the way. f16 is pretty much it. Opening 2 or 3 stops and it will overexpose. Ideally, I'd like to use the lens for outdoor cars shows. There's always some Bozo who will walk into the frame and I hope to be able to use a tripod and long exposures to get rid of them. You can't wait them out, they're lined up waiting for a chance to walk in front of you. So, I'm looking at ND filters and hope to lean on your wisdom. Stacking on the 28mm might create some vignetting problems. The Cokin system has the potential for light leaks and potential damage to the filters while moving around. Are variable filters as bad as some people say or are the problems operator error? I'd like to do at least 30 second exposures but I don't know if the variable filters will darken enough for that. Ideas? Suggestions? (Other than "Quit sniveling about a lens that's too fast.") Thanks for your input!
According to the Sunny 16 Rule, at ISO 100 in full sun at f/16, you should be getting around 1/90"-1/125" shutter speed. In open shade, that should get you down to 1/15". You're still going to need a ton of ND and with wide angle, stacking will be problematic with vignetting. But if you're doing this to eliminate folks around the cars, and you're bringing a tripod anyway, I agree with post #3 as a solution, and then either use masks or clone stamping in PP.

If you shooting film, Velvia 50 ISO is absolutely stunning and keep in mind, you could get some really cool images of stationary cars with people blur at 1/8". No it won't be catalog clean, but it would look more unique with the buzz of movement around the showcase cars.

01-01-2016, 03:59 PM   #5
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A couple of polarizing filters would give you a variable ND filter. You likely can get used linear PL filters for relatively low cost. I find the standard Tiffen ones to be fine--although I don't use them as a ND filter. With 3 additional reflecting glass surfaces you likely may get flare where a strong light source is present.
01-01-2016, 04:13 PM   #6
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QuoteOriginally posted by gifthorse Quote
I have a Vivitar 28mm f2 close focusing lens. Nice lens. I'm pretty happy with it. Except..... in bright sunlight I can't open it up. At 100 ISO with a CPL filter the only way I can get shutter speeds less than the 1/1000 is to stop down all the way. f16 is pretty much it. Opening 2 or 3 stops and it will overexpose. Ideally, I'd like to use the lens for outdoor cars shows. There's always some Bozo who will walk into the frame and I hope to be able to use a tripod and long exposures to get rid of them. You can't wait them out, they're lined up waiting for a chance to walk in front of you. So, I'm looking at ND filters and hope to lean on your wisdom. Stacking on the 28mm might create some vignetting problems. The Cokin system has the potential for light leaks and potential damage to the filters while moving around. Are variable filters as bad as some people say or are the problems operator error? I'd like to do at least 30 second exposures but I don't know if the variable filters will darken enough for that. Ideas? Suggestions? (Other than "Quit sniveling about a lens that's too fast.") Thanks for your input!
Not a fan of variable ND for wide angle lenses. For your application I recommend you pick up a set of three ND screw-in filters: -3 stops, -6 stops, -9 stops. That will cover you for 95% of your requirements. This is my setup and I have now standardized on 67mm filters for all my lenses, including my primes.

YMMV

Michael
01-01-2016, 04:13 PM   #7
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Some feedback from using 10 stop filters

I'm glad some people can talk the figures as it's not my strong point.

I have a 77mm Hoya 9 stop filter and a 49mm B&W 10 stop filter B+W 49mm 3.0 ND 110 Filter 65-1066169 B&H Photo Video.

The 30sec in the daytime will be hard to achieve with these filters as already identified. Stopped down to f11 with the B&W 10 stop I tend to find I'm about 10 secs in direct sunlight, but this is dependant on the usual suspects like lens, subject you're shooting, time of day, direction of the light etc. You might get another 2-5 secs stopping down to F16, then the only other way of adding time with the filter would be to under expose. Even then you're not likely to see 30secs with the 10 stop. I wouldn't recommend layering filters as you will lose too much resolution and likely to introduce issues with ghosting.

If you decide to give the 10 stop filter a try there is a technique to using these filters. To get composition correct I suggest live view to compose then turn it off and use mirror lock up and watch for people contacting the tripod feet if it's really busy. And despite what some people think I recommend you cover the viewfinder especially if you shoot with the sun behind you. You can use a dedicated cover or something else.

So there's compromises with the filters and no doubt with the software options too, but have you tried getting in early or speaking to organisers about other times you might be able to get access when there are no crowds? Maybe it's not that type of autoshow but if it is they can't say no if you don't ask.

Anyhoo, best of luck with whichever way you go.

01-04-2016, 07:39 PM   #8
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I do appreciate the suggestions, everyone! This is what I'm facing...

This continues for about five blocks at half a dozen different locations around town. (5000+ cars on display) The cars parked are on the streets so there's always people walking around. Most people are just walking by, looking at the cars and paying no attention to the person who has been waiting patiently for a shot with no people in the frame. Some people will stop for a few moments to take a picture. (No, as tempting as the idea is, I don't return the favor.) At night the cars are cruising. I'd like to use the Vivitar to get closer to the cars and leave less room for someone to walk between me and the car.
I think I'll start with the three piece ND set as was suggested. When the annual car show returns in August, I'll give the Gimp method a try. If I can find a couple of CPL filters I'll see what a homebrewed variable filter will do. Again, thanks for the input!
01-06-2016, 03:51 PM   #9
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Ok, but I've gotta question your intent here.

If I eliminate all of those obnoxious people in that image -- what's the point? It simply would look funny (to my mind) at that time of day.

Consider your purpose for that shot.

Would a late night shot add a new perspective with few unwanted distractions and offer a slower shutter speed? Stacked shots?

Make lemonade?
01-06-2016, 04:48 PM   #10
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Even if you are able to achieve a 30sec shot with a tripod, the chance someone might want to linger around peering at the dashboard for some 5 seconds or so will be quite high, resulting in ghosting images. You are shooting at a popular public venue, trying to exclude all them "bozo" from your shots is simply unrealistic. You'd be better off to get a wider lens (eg. Sigma 10-20) so that you can get a lot closer to the car and still include all or most of the car in your shot.
01-07-2016, 05:50 AM   #11
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B&H has 10 stop ND filters starting at roughly $20. I'm not sure if that's enough to get you where you want to be, but it's a fairly inexpensive way to see if you're on the right path.
01-07-2016, 06:24 AM - 2 Likes   #12
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Hmmm, let me offer my view and get as close to what you actually want as possible. By all means, get an ND10 (or even ND11) filter but don't stack CPL's or use variable ND's. Linked with a wide viewing angle and the small apertures you need, you will run in to the dreaded cross-effect. (called like that because you end up with dark X-like shading all across the frame)

No w combine both suggestions given in this topic: take multiple exposures as well as extending the exposure times of each individual shot with an ND filter. Layer the exposures in Gimp (or Photoshop or any other layer-enabled software package) and proceed to use the eraser tool on each layer to erase people (or ghosted images of people), making sure each layer has transparency set.

If all is well this will create many layers with "holes" in them where (ghosts of) people used to be. Withe any luck a hole in one layer will be placed over a solid background in another. In the end, after collapsing all layers into one, you will have little imperfections left which can be cleaned up by using the clone tool or the "heal-selection" script.

End result should be an empty street. You may need as little as 4 or as many as 20 shots, depending on the situation.
01-27-2016, 03:59 AM   #13
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If you're still chasing an ND filter

Hi again,

Not sure if you're still considering an ND filter that will give you the long shutter speeds through the day or not, but I use a Singh Ray reverse ND filter and never thought to suggest them in my original post.

They indicate they have 15 and 20 stop ND filters that would likely fit your needs. I expect you will choke once you see the price, I did.

Anyhoo, have a look for yourself: Mor-Slo 5, 10, 15 and 20-Stop Solid Neutral Density Filters | Singh-Ray Filters

The prices are shown in the select size drop down menu. Make sure you're sitting down.

Tas
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