Efke R50 response to contrast filters

[valdas]

If I am not mistake Efke 50 (35/120- KB and R) has somewhat reduced spectral sensitivity to red. So, I was wondering if I can use orange filter with this film. Any real life experience (what exposure compensation is needed?)?

 

[charjohncarter]

I have only used Efke r25 (also Efke 820 IR but that is a different story). And I didn't use any filters. These were my results:


https://www.flickr.com/search/?user_id=8178676@N04&sort=date-taken-desc&text=efker25&view_all=1

The people below on Photonet have some help for your problem:

https://www.photo.net/discuss/threads/efke-iso-25-film-spectral-sensitivity-change.18795/

 

[Skiff]

If I am not mistake Efke 50 (35/120- KB and R) has somewhat reduced spectral sensitivity to red. So, I was wondering if I can use orange filter with this film.

Of course you can use an orange filter.

Any real life experience (what exposure compensation is needed?)?

The exposure compensation is dependent on the filter factor. Look what filter factor your orange filter has. Or use a SLR, the through-the-lens metering is considering / including the filter factor.

 

[valdas]

Of course you can use an orange filter.



The exposure compensation is dependent on the filter factor. Look what filter factor your orange filter has. Or use a SLR, the through-the-lens metering is considering / including the filter factor.

The reason I asked is that, I understand, fully ortho film (with no red sensitivity) makes red and orange filters impossible or compensation should be much more than normally (e.g for panchromatic film).

 

[valdas]

The people below on Photonet have some help for your problem:

https://www.photo.net/discuss/threads/efke-iso-25-film-spectral-sensitivity-change.18795/

yes, I have read this, and this triggered my hesitation- I guess red could be too much of the risk (or need to experiment with the exposure), but not sure about orange... yellow is safe, I assume...

 

[Skiff]

The reason I asked is that, I understand, fully ortho film (with no red sensitivity) makes red and orange filters impossible or compensation should be much more than normally (e.g for panchromatic film).

R25 is not a fully ortho film. Therefore you can use an orange filter.

 

[valdas]

R25 is not a fully ortho film. Therefore you can use an orange filter.

I realize it's not fully ortho, but still - reduced sensitivity to red specter and reported issues with red filter, so I was wondering in there is more adjustment needed with orange. I guess I'll need to test it...