Quick question: Filter correction on yashica electro 35

[pedro.m.reis]

Hi.
Today in my weekly visit to the lab i use, i bought a filter to use with my yashica electro 35. Its an "Hoya HMC Filter, multi-coated, Orange(G)". I beleive its necessary to compensate in exposure when using this. Any one can quickly say me how can i do it? I beleive that the only thing i can do is adjusting the ASA dial since the electro is aperture priority.
I shoot mainly AGFA APX and Tri-x.
Thanks.

 

[RichardS]

If you have an MG1 Electro you don't have to do anything because the meter will read the light coming through the filter. With all other models, I think, you'll have to change the film speed.

I don't know what the filter factor would be for your particular filter, but use that number to adjust the film speed.

Also, this site has a Yashica forum where you are likely to get more answers to questions about the Electros.

Dick

 

[beethamd]

Hi Pedro,
I worked out an equation to help me with my Bronica RF645.

If you call the Filter Factor ff, and n is the number of stops of compensation, I use -

Two to the power n = ff
So, for a ff of 2 we know that two to the power 1 = 2 - meaning one stop of compensation is required.
For a ff of 4 we know that two to the power 2 = 4 - meaning that two stops of compensation is required.

For Filter Factors of 1.2 etc, it's best to use logarithmic notation.

In general form - the exponent in the equation '2 to the power n = ff' is usually written as log(base 2) ff = n.

OK - if you use a filter with a ff of 1.2, we have a compensation requirement of log(base 2)1.2. That should give 0.26, meaning that 0.26 stops of compensation via the ASA dial are required.

Here's a table of other Filter Factors, with their corresponding compensation, in stops. -

ff,compensation
1.1, 0.14
1.2, 0.26
1.3, 0.38
1.4, 0.49
1.5, 0.58
1.6, 0.68
1.7, 0.77
1.8, 0.85
1.9, 0.93
2.0, 1
2.1, 1.07
2.2, 1.14
2.3, 1.2
2.4, 1.26
2.5, 1.32
2.6, 1.38
2.7, 1.43
2.8, 1.49
2.9, 1.54
3.0, 1.58

I hope this helps. If there are mistakes here, please let me know.

 

[Solinar]

Twenty years later, I still know this one. I used an old Electro GT through out the 1970's before succumbing to SLR's.

Anyway, for ISO 400 film with an orange filter, set the film speed dial to ASA 100 and the camera will provide a necessary shutter speed that is 2 stops longer.

For ISO 100 film, you need to set the film speed dial to ASA 25 when using an the Orange filter.

Don't forget to reset the film speed, once you remove the filter. I usually forgot to change it back.

 

[pedro.m.reis]

Thanks ppl!!

 

[whitecat]

What would I set the asa at for my yashica 35 using a deep yellow filter of 3.3 filter factor? I am using asa 400 film. 100+?
Thanks

 

[f16sunshine]

If ever in doubt about how many stops to compensate for a filter. Place the filter over a light meter diode and you will see how much light it absorbs. Same can be done using another camera that has ttl metering. 🙂

 

[whitecat]

Just found my answer.....

http://www.yashica-guy.com/document/qa.html