Stupid Question

Adrian Sierkowski · July 21, 2008

Hey All.

I have a tiffen 81EF N.3 Now, I know that normally the 81ef takes 2/3 of a stop, but this one's N.3 designation leads me to believe it takes a whole stop. That's right? It's not 1 whole stop over the 81ef's 2/3rd (e.g. I'd open up 1 and 2/3rd stop to compensate) but rather I open up 1 stop to compensate?

I ask because i'll be shooting '17 outside and want a slight blueish look. I haven't got the budget, sadly, to test, and It's been awhile since I reached for this filter. My brain's just not working today!

Mike Rizos · July 21, 2008

I think the filter is combonation 81EF and ND.3, so 1 2/3 total.

Max Jacoby · July 21, 2008

You have a 81 filter and an ND3 filter combined into a single filter, so you need to compensate for both, i.e. 1 2/3 stops.

If you're ever unsure about filter compensation, just take a reading with you light meter, then put the filter over it and take another reading, the difference is how much you need to compensate.

Adrian Sierkowski · July 21, 2008

Thanks to the both of you.

I had always wondered about doing that with my meter. Thanks for the "it's ok." Max.

I had checked on tiffen's site, but of course didn't mention anything about it. I'll give it a light meter whirl later on tonight.

Edited July 21, 2008 by Adrian Sierkowski

Adrian Sierkowski · July 23, 2008

Actually, after checking with my meter ,it seems to be just 1 stop. Guess Tiffen labels it so the 2/3 compensation and the level of ND they put into it give you exactly nd.3?

Reading off of a grey card was a 2.8(1) and a 2.0, so 1 and 1/10th difference. For shits and giggle I tried it again in my room, off of my white wall (different set up) and got, again 2.8(6) and 2.0(6)

All of these were of course in Spot mode on my Sekonic. for anyone else who has such a brain fart as I.

Mike Panczenko · July 23, 2008

When you have a filter thats a combination of multiple filters, you need to compensate for all of the contained characteristics. So if you have an 85N3- it would be 1 2/3 stops (85= 2/3 + N3= 1 stop.) If you have an 85pola, it would be 2 1/3 stops (85= 2/3 + pola = 1 2/3.) If you have an 85N9- it would be 3 and 2/3 stops (85= 2/3 + N9= 3 stops.) Whatever filters are there, break it down into the individual filters and add from there. If you're meter is reading it as one stop, it can be due to slight differentiations from the theoretical to the actual, your individual meter's response, any number of things. But if it is 85N3, Tiffen won't label it with the N3 to show an overall loss of 1 stop. The fact that it is a loss of one stop vs 1 2/3 is just a matter of the actual, physical manufactured piece of glass vs. the theoretical. Hope this helps!

Adrian Sierkowski · July 23, 2008

Thanks Mike. Maybe ought have the meter checked out too before I shoot.

I'll compensate for the 1 and 2/3rd stop as suggested, and probably right.

I'll see if I can test just to make sure, though.

Mike Panczenko · July 23, 2008

Thanks Mike. Maybe ought have the meter checked out too before I shoot.
I'll compensate for the 1 and 2/3rd stop as suggested, and probably right.

I'll see if I can test just to make sure, though.

Well, I'd actually go by the meter reading. Get your meter checked, but I'd trust the meter. Sometimes the same filters from different manufacturers meter differently. Color neg can handle it, so you'd be fine either way. But, I don't think you can go wrong going by the actual spot reading. Get the meter checked, but I wouldn't be surprised if it turned out to be accurate.

Tim Terner · July 23, 2008

Hi Adrian, Quick test would be just to put it in front of a digital SLR on manual and take a pic then one without

Adrian Sierkowski · July 23, 2008

Sadly no DSLR, yet. I'll throw it in front of my F4 when I get home just to double check. I also shot Tiffen an e mail to double check with them. Infuriating really, the minor inconsistency. I had read recently about the 18% grey myth of spot meters from a link on CML. I know I'm fine on the V2 stocks for 2/3rd of a stop either way; just might need all the "play around" room possible for post on this project. Given the tiny budget for lights and the like, I have a feeling I'll need all the toe/shoulder room I can get!

All the best,

~Adrian

John Sprung · July 23, 2008

Given the tiny budget for lights and the like, I have a feeling I'll need all the toe/shoulder room I can get!

In that case, maybe put this filter aside, and go with a straight 81 EF.

-- J.S.

Adrian Sierkowski · July 23, 2008

Lol problem is I came to own this filter, yet no straight 81EF. Came with my camera when I bought it as part of the package, including an straight 85 which is what I'd normally use exposing 7217 in daylight.

In any case, I just checked again off of my F4 and a friends Minolta spot, and they all read 1 stop difference with w/o the filter. I'll just go with that. and see

Edited July 23, 2008 by Adrian Sierkowski