ND filters

[Donald]

This interesting thread has covered a number of different aspects of ND use.

By way of a small contribution to the colour cast debate. There is often criticism of the problem of the cheaper products in terms of colour cast. What I have found with Cokin is that the GNDs are fine, it is the ND (I have a 3-stop) that really creates significant and problematic colour cast. So much so, that I consider my purchase of that 3-stop ND to have been a bad buy.

[Bobobird]

That is why 5was necessary to see for myself.

People who used welder's glass have said about the same but green and also hard to remove so b&w was the only option.

Mind you - for less then $5 a piece, it may just be useful for to cut out light and get b&w's instead of doing too much software conversion to tonal ranges.

[Donald]

There's one other thing I'd like to contribute to this discussion. It relates to that point just made about a bad colour cast meaning that you really have no option but to produce a B & W image (I hope I'm correct in understanding that this is the suggestion).

That's not a view I'd agree with.

If you want to make a good B & W, I think you have got to start from the right place. And that includes the colour data in the file that's going to be worked with. Why? Because if you are going to be applying filter effects or working with colour sliders (e.g. red or yellow to darken skies) as part of your B & W conversion workflow, then you need to have the correct colour data in the file as your starting point.

That's why, although, as folks on here know, I shoot knowing I'm going to make a B & W image, I use a WhiBal card so that I can correct colour on the RAW file before I commence the conversion.

[Bobobird]

Now I know why my b&ws suck as much as my landscapes.

I have never felt comfortable with adjusting WB in ACR and a white balance card was in the shopping list, just never got round to it. Tomorrow will certainly get one.

Thanks Donald.

[Manfred M]

Now I know why my b&ws suck as much as my landscapes.

I have never felt comfortable with adjusting WB in ACR and a white balance card was in the shopping list, just never got round to it. Tomorrow will certainly get one.

Thanks Donald.

That red colour cast you are complaining will also be in the B&W image, but you will have converted it to monochrome. I suspect you are not looking at a pure red either, and expect that there would be some yellow component as well. The welder's glass is primarily designed to filter out the UV component in the welding arc, so all the short wavelengths (blue end of the spectrum) are going to be filtered out and the long wavelengths (red end of the spectrum) are going to be able to pass through.

The red (or potentially red / yellow) cast means that anything containing your cyan or to some extent blue wavelengths are going to be impacted; sky, water, leaves and grass are likely going to look off after the b&w conversion.

[Colin Southern]

Now I know why my b&ws suck as much as my landscapes.

I have never felt comfortable with adjusting WB in ACR and a white balance card was in the shopping list, just never got round to it. Tomorrow will certainly get one.

The "golden rule" is "don't white balance from eye"; unfortunately the brain is highly influenced by many things when it comes to colour. We can adjust things until it looks perfect - then adjust it using a grey card - and find that we've been significantly off.

With grayscale images though - although WB still affects the image - nothings says that a technically correct WB will be the one that makes the image looks best (in fact I would suggest that rarely does a greyscale image look it's best with a technically correct WB). Just use a visually correct one.

[Donald]

(in fact I would suggest that rarely does a greyscale image look it's best with a technically correct WB). Just use a visually correct one.

I acknowledge the point, but would suggest that with the tools available in various pieces of software nowadays, the argument only stands up if we qualify it with, 'dependent on the software you are using to do the conversion'.

When we had no filter effects etc in B & W conversion software, then it is quite right that we had to 'work' the colours in the file before we made the greyscale conversion. But, I'm not sure that this is case with tools such as Silver Efex Pro 2 and the like.

[Ollokot]

I have been reading this thread with great interest as a thought about the purchase of a GND Filter has rambled around in my mind for some time now. The Singh Ray filters are noted for their quality and the price reflects this, what other brands would you good Folks recommend for their quality.
Best Wishes, Pat

[Donald]

I have been reading this thread with great interest as a thought about the purchase of a GND Filter has rambled around in my mind for some time now. The Singh Ray filters are noted for their quality and the price reflects this, what other brands would you good Folks recommend for their quality.
Best Wishes, Pat

Pat

I've always thought of it being in terms of a hierarchy. At the top of the tree you have Singh Ray. The you have Lee. And then Cokin. Perhaps the manufacturers wouldn't think this was fair and there are others makes, but this is how I think about it.

[Colin Southern]

I acknowledge the point, but would suggest that with the tools available in various pieces of software nowadays, the argument only stands up if we qualify it with, 'dependent on the software you are using to do the conversion'.

When we had no filter effects etc in B & W conversion software, then it is quite right that we had to 'work' the colours in the file before we made the greyscale conversion. But, I'm not sure that this is case with tools such as Silver Efex Pro 2 and the like.

Hi Donald,

Not sure if you mis-read what I wrote or not, but I'm struggling to follow you on this one. When I'm doing a greyscale conversion ("B&W") I'll usually simply start by setting the saturation to zero, and then having a play with white balance and a few other controls until it looks it's best. Unlike a colour shot, I don't strive to get the white balance technically correct at any point in the workflow - it's just all done by eye.

[Colin Southern]

I have been reading this thread with great interest as a thought about the purchase of a GND Filter has rambled around in my mind for some time now. The Singh Ray filters are noted for their quality and the price reflects this, what other brands would you good Folks recommend for their quality.

None. I just don't trust the performance of the cheaper ones.

[lillidiver]

Hello people!!

I've been following this thread with interest !!

I have an opportunity to acquire this filters and I believe GND serve me better. Lee filters and Singh-Ray Filters seem to be better options, but for my reality a bit expensive, someone here has experience with Tiffen filters?

I thought about them because there is no need for adapters like other squares filters.

A filter like ND 0.9 (3 stops) can make the picture pink / red? Change colors ?

My goal is to slightly decrease the brightness of the sky in a sunset or a waterfall long exposure for example.

Anyway thanks for your help !

Sorry for my english....it's difficult trying learn photography in a other language !!!

[Ken MT]

I am very happy with Marumi ND 2-400. Below is comparison at f9, 100 ISO, manual focus. I do not notice any significant colour cast. The change in shutter speed is shown in each from 1/50 sec to 0.4

[lillidiver]

Ken, thanks for your help! I will look for more information about the Marumi's filters !!!!

[Colin Southern]

I have an opportunity to acquire this filters and I believe GND serve me better. Lee filters and Singh-Ray Filters seem to be better options, but for my reality a bit expensive, someone here has experience with Tiffen filters?

I thought about them because there is no need for adapters like other squares filters.

Hi Lillian,

If you're talking about GND filters - and not ND filters - then you definately - positively - 100% need to avoid the round types as the transition zone is fixed, and in real world photography, you'll need to move that transition zone all the time, making them pretty much a total waste of money.

[lillidiver]

Hi Lillian,

If you're talking about GND filters - and not ND filters - then you definately - positively - 100% need to avoid the round types as the transition zone is fixed, and in real world photography, you'll need to move that transition zone all the time, making them pretty much a total waste of money.

thank you Colin
I thought that it is possible to turn these GND filters left / right such as the polarizers ...where I want decrease the brightness

[Colin Southern]

thank you Colin
I thought that it is possible to turn these GND filters left / right such as the polarizers ...where I want decrease the brightness

Hi Lillian,

You'll normally have the brightest part of the scene at the top, but the problem is that the transition on those filters always occurs through the middle of the lens whereas in the scene your shooting, sometimes you'll want it - say - 1/3 down from the top whereas in another - say - 2/3 down from the top.

Circular GND filters are to photography kinda like string and cans were to telephone communications (perhaps a little harsh, but you get the idea!).