[newarts]

I bought a Marumi +5 to test head-to-head vs the Raynox DCR 150. Here are the surprising results (about a 1:1 shot of my laptop screen):


The *Raynox 150 unquestionably wins*

I suppose it is flare from the Marumi that makes its contrast deplorable. The Raynox required 2 stops more exposure compared to the Marumi - I don't know why (edit - likely because the Marumi allowed an extra two stops of light to be flared into the photo.). The resolution of the Raynox is also substantially better than that of the Marumi.

Edge distortion is about the same & I don't know how much is due to the primary lens.

The poor contrast (or flare) from the Marumi results in only about 1/2 of the K-x sensor's dynamic range being used. The room was dark so there was no side lighting striking the lens (except from the laptop screen itself - which could be substantial but this flare is so bad it would take a LONG hood to kill the extra light.....I'll check it out.)

*My conclusion is the Marumi +5 performs poorly compared to the Raynox DCR 150*.

Dave

EDIT the terrible flare shown by the Marumi is defeated by running a hood all the way from the lens to the subject; in that case the Marumi might show poor transmission in the blue and lower resolution than the Raynox.

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Last edited by newarts; 05-13-2012 at 04:09 PM.

[audiobomber]

Wow, that is quite the difference in resolution. I didn't think there would be that much difference between achromatic diopters.

[newarts]

The Marumi's flare problem is still bad when the pop-up flash is used to illuminate a subject in a dark room. The resolution is also poor compared to the Raynox DCR 150 (both photos on a K-x, DA 55-300 at 300, ISO 500.. about 1.5:1 mag)


Maybe I have a bad copy? I'm surprised the Marumi's performance is so poor.

Dave in Iowa

[snostorm]

Hi Dave,

It could be the FL (300mm with this lens) used in combination with the Marumi +5 Acromat.

I have both of these, and just tried it. I get similar results at 300mm with this lens combo, but at shorter FLs with the same lens, the Marumi +5 shoots considerably sharper, so it's possibly not the Marumi's fault.

I'd previously used the Marumi on other lenses (mostly with 50-100mm lenses adapted to the Q) with no problem, so I was curious about your post. I don't recall getting any recommendations with this achromat, but in the past, these diopters commonly were optimized for specific lenses and/or FL ranges. I'm thinking that this one is not optimized for use at 300mm.

Here's a site that lists a lot of Achromatic diopters (but not the Marumis) and shows that the Raynox DCR 150 and 250 are optimized for use at 300mm.

Fuzzcraft.com | A list of achromatic close-up lenses | Photography, audio and light DIY projects

I've just confirmed this somewhat by trying it on my FA* 300/4.5 (so the lens is not at fault), and I got similar bad results. However, with my DA 50-200 at 200mm, the Marumi shot fine. It looks like this diopter is optimized for lenses up to @ 200mm.

Scott

[newarts]

Hi Dave,

It could be the FL (300mm with this lens) used in combination with the Marumi +5 Acromat.

I have both of these, and just tried it. I get similar results at 300mm with this lens combo, but at shorter FLs with the same lens, the Marumi +5 shoots considerably sharper, so it's possibly not the Marumi's fault.

I'd previously used the Marumi on other lenses (mostly with 50-100mm lenses adapted to the Q) with no problem, so I was curious about your post. I don't recall getting any recommendations with this achromat, but in the past, these diopters commonly were optimized for specific lenses and/or FL ranges. I'm thinking that this one is not optimized for use at 300mm.

Here's a site that lists a lot of Achromatic diopters (but not the Marumis) and shows that the Raynox DCR 150 and 250 are optimized for use at 300mm.

Fuzzcraft.com | A list of achromatic close-up lenses | Photography, audio and light DIY projects

I've just confirmed this somewhat by trying it on my FA* 300/4.5 (so the lens is not at fault), and I got similar bad results. However, with my DA 50-200 at 200mm, the Marumi shot fine. It looks like this diopter is optimized for lenses up to @ 200mm.

Scott

Scott,

I am pleased to read your response as it supports my results at 300mm and provides more info about suitability at other focal lengths. I had no idea that the focal length of the primary lens could have such a strong effect & will explore that using the Marumi at other focal lengths.

Thanks again,

Dave