Jump to content

Why are +0.4, +0.5 diopters more desired than +1 diopters?


Recommended Posts

Can some explain to me why +0.4 and +0.5 diopters are more desirable than +1 diopters? Are +1 diopters terrible? I would assume using +1 would grant the user the the option of being able to shoot at the distance a +0.5 allows and closer since its +1. Maybe someone can enlighten me on the pros and cons of each diopter strength.

Link to comment
Share on other sites

EOSHD Pro Color 5 for Sony cameras EOSHD Z LOG for Nikon CamerasEOSHD C-LOG and Film Profiles for All Canon DSLRs

if you can find a +1 achromat it'll still be a great addition to any lens collection.  a +0.5 non achromat isnt really that special since it doesnt correct for CA and using on anything more than a small sensor/aperture it'll degrade the optical quality.  But the reasons a +0.4 achromat is more desirable than a +1 achromat is this:-


a +0.4 achromat will reduce the minimum focus distance of your lens to almost half it;s original minimum focus (if you have a 1m minimum, the +0.4 achromat will change minimum to 0.6m.  However due to the weak diopter value it will still allow focus to all the way to 2.2mtrs.  this is a really good focus range for racking indoors.


a +1 achromat will reduce a 1m minimum to 0.2m so can get closer, but maximum distance when the lens is set to infinity will be 1 meter.

As a result, your focus pull range is drastically reduced.


So to answer your question, the reason is that a weaker diopter value lends itself well for users requiring focus pulling between 0.6m - 2.2m - still a rather useful range for medium/close shots, or powerful closeups from fast 85mm lenses which tend to have a minimum focus of 1m or longer.

Link to comment
Share on other sites

  • 2 months later...

I'm yet to be convinced that the difference between an achromat and a good single-element close up filter is terribly substantial (I would be happy to be proved otherwise, if anyone wants to pit a Tokina 0.4 against a Tokina 0.5 I'd love to see the results!), but the 0.4/0.5 strength gives you a really useful focusing range with an Iscorama, whereas no filter gives you infinity to 6 feet (too far to too far) and a +1 gives you too close to too close.

I don't get it, though. Most lenses aren't apochromatic and a 0.5 filter won't ruin your optics much. I don't think a decent 0.5 single-element filter will ruin the party tremendously, though I guess if you're spending $4k on an Iscorama, why not drop a few hundred extra on the best CU filter you can find.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • EOSHD Pro Color 5 for All Sony cameras
    EOSHD C-LOG and Film Profiles for All Canon DSLRs
    EOSHD Dynamic Range Enhancer for H.264/H.265
  • Create New...