How compensate for color filters?

[wrs1145]

I've got 2 cameras w/ meters, (an Olympus 35SP & a Yashica Lynx) but with non-TTL or non -thru the lens metering systems. My question is how do you meter for them with colored filters?

Many thanks,
Bill

 

[CMur12]

Hi Bill -

Where is the metering cell located on your cameras?

On all of the fixed-lens compact RFs that I have had, the metering cell is still behind the filter, so the meter should automatically compensate for it.

Otherwise, if the metering cell is located elsewhere, you could hold the filter over the cell and take a reading. You could then note the difference and dial that into the settings after that.

- Murray

 

[wrs1145]

The meters for both are NOT TTL. That's good solution I have thought about.

 

[CMur12]

Bill, on my cameras the metering is not TTL, but it is through the filter.

I just looked at pictures of your cameras online, and it looks like your metering cells aren't colocated with the lens, like mine are. So, I think my last suggestion of holding the filter over the metering cell to take a reading and noting the difference would be your best bet.

There are standard values for most colored filters, which you could dial into your settings, but sometimes they vary a little from manufacturer to manufacturer. If you have the original manufacturer's packaging for your filters, they should give the filter factors for their filters.

- Murray

 

[p.giannakis]

There are cameras that although the metering is not TTL, the cell is close to the front element so that when you screw a filter, the cell is behind the filter and compensates automatically.

This is not the case with your cameras. Both of these cameras have the cell on the top plate.

The only way is to know the filter factor of the filter you are using. The most common are a 2x, meaning you need to add a stop (ie. Instead of 400iso, set it to 200). You need to find the packaging of the filter, it should be stated there.

 

[p.giannakis]

Also, if you are not sure of the filter factor, put the filter on a camera and take two readings - one with the filter and one without. If without is (let's say) 1/250 and with the filter you get 1/125, then it is a 2x filter (one stop). Just make sure you meter of a smooth, evenly lit surface (I.e. a wall) so that you don't get wild variations.

 

[peterm1]

What you can do is first make a trial reading of the subject (or an 18% grey card or similar - more of that in a moment) and take a mental note of the reading. Then take the filter off your lens and take another reading of the scene (or grey card) while holding the filter in directly front of the meter. Again, make a mental note of the reading and check the difference between the first and second reading this will tell you how many stops to open up the aperture. I am assuming you ae shooting in full manual mode. For many filters it is probably going to be about 1 stop in my experience, but for a pale yellow or apple green one it may be a half of a stop and for a deep green or red maybe 1.5 or 2. Now all you need to do is to use the same adjustment factor whenever you are using that particular filter on the lens. As to a grey card, I had read somewhere that well used bitumen on a road surface was pretty close to an 18% grey and so I found it to be - it was a handy substitute for metering if the subject is backlit etc which would otherwise mess up the metering of the subject directly. Just take your reading off the road surface and set the camera lens accordingly. Then make the necessary adjustment to the exposure for the filteryou are using and you are good to go.

To be honest when I was shooting "old school" (but with a hand-held meter not an in camera / non TTL one - which never the less amounts to the same when you think about it) I would often prefer to use ambient metering (i.e. measure the ambient lighting). As long as the lighting did not change I could shoot at those settings all day. If cloud came over of the sun came out I would just stop down one more stop or open up one more stop. Of course you still need to make the allowance for the filter I described above as well.

 

[Joao]

For ISO 100 film I used 1/2 stop for yellow filter, 1 stop for orange filter and two stops for red filters

Joao

 

[Harry the K]

There are compensation tables for filters. The filter factors are written on the filters.

 

[wrs1145]

I finally got it! A combinion of light meter and the head guy here on a website gave me my guidance.

Many thanks,
Bill