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Pascal Garnier

RJ jinfinance Focal Reducer

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Can someone clarify something about aperture equivalence for me. The focal reducer will increase light gathering by one stop, but how will it affect the DOF shallowness? So 35 f2 lens on mft would become 25mm f1.4, and then multiply again by the mft crop factor, it becomes a 50mm f2.8?

yep. You are correct. Dof of 50mm 2.8 fullframe with the light gathering capability of 1.4.

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

if i want to use canon and nikon lenses.... what is the right adapter ?

Can i get for example canon eos focal reducer for my canon lenses, and then  a simple adapter from nikon to canon and then the focal reducer ?

Which is the most "universal" version ? (so I can use most of my lenses - M42, nikon , canon etc)

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Had these conversion charts BM'd for a while, just in case you need help with conversions:

 

http://forum.blackmagicdesign.com/viewtopic.php?f=2&t=14039

 

 

The only attempt so far, that I can find, of a comprehensive look at these adapters relative to the more expensive MB offerings:

 

http://www.dpreview.com/forums/thread/3627547#forum-post-53156458

 

...of course, charts don't tell the whole story.  Just ask the Helios 44.

I'm still a bit dubious about that test, but as you said charts don't always tell you the whole story!

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Yeah, real world shooting will be more forgiving.

 

The Mitakon looks pretty good relative to the Metabones.  Being softer isn't necessarily a bad thing in some cases.  It's like a focal reducer, stop booster and OLPF all in one!

The sports car test that i posted was pretty much the same sharpness with & without.

& there have been people saying that with the Metabones SB moire etc... rears its ugly head a lot more than without - so sharper doesn't mean better.

As far as the other FRs, i think they are much of a muchness & getting anal about which is better isn't really worth it.

I'll just be happy to use my Russain & Super Takumar lenses again, with the added bonus of them being that little bit wider & faster!

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I'm a bit late coming to the Party ,

 

but today I got a Mitakon Lens Turbo speed booster Nikon AI- Micro 4/3

I got this specifically to use with the Angenieux designed Tokina AT-X Pro Series 1 28-70mm f2.6-2.8.

This is a legendary classic Angenieux lens design and has a very very cinematic look to it ,

I like using it with a Tiffen ND16 so I can shoot f2.6 outside , stunning narrow dof bokeh heaven with this lens.

 

So the Lens Turbo on this lens makes it an f2 ish 20mm-50mm ish lens

 

First impressions are wow !! the Lens turbo increases sharpness alot on this lens , it was good before but now Im getting peaking blue lines all over the place on object edges on my G6 - alot more than before

at at 28mm (which is now 20mm) it is very sharp

 

so by using this Lens Turbo it has given me a 20mm f2 sharp lens which is very useful.

 

The Lens turbo does a superb job , I like the look it produces , wider, faster, brighter and sharper!!

 

Also if you put a +0.5 Diopter on the front of your lens that also increases sharpness alot on these speedboosters

you loose a degree or two of field of view , BUT for objects 10 feet or nearer it has a big effect increasing sharpness.

 

This trick will be useful on the cheaper Chinese RJ Jinfianance speedboosters as they are a bit softer than the Mitakon Lens Turbo

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I'm a bit late coming to the Party ,

 

but today I got a Mitakon Lens Turbo speed booster Nikon AI- Micro 4/3

I got this specifically to use with the Angenieux designed Tokina AT-X Pro Series 1 28-70mm f2.6-2.8.

This is a legendary classic Angenieux lens design and has a very very cinematic look to it ,

I like using it with a Tiffen ND16 so I can shoot f2.6 outside , stunning narrow dof bokeh heaven with this lens.

 

So the Lens Turbo on this lens makes it an f2 ish 20mm-50mm ish lens

 

First impressions are wow !! the Lens turbo increases sharpness alot on this lens , it was good before but now Im getting peaking blue lines all over the place on object edges on my G6 - alot more than before

at at 28mm (which is now 20mm) it is very sharp

 

so by using this Lens Turbo it has given me a 20mm f2 sharp lens which is very useful.

 

The Lens turbo does a superb job , I like the look it produces , wider, faster, brighter and sharper!!

 

Also if you put a +0.5 Diopter on the front of your lens that also increases sharpness alot on these speedboosters

you loose a degree or two of field of view , BUT for objects 10 feet or nearer it has a big effect increasing sharpness.

 

This trick will be useful on the cheaper Chinese RJ Jinfianance speedboosters as they are a bit softer than the Mitakon Lens Turbo

Hi, could you post some sample photos/videos so I can see how this lens performs? Also could you tell me how its ergonomics are?

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yes

 

if you point it direct at the sun , as in over exposed by 3+ stops under certain conditions it does produce a blue/purple spot relative to your apperture size......wide open apperture = big spot !

 

but I cant see it being a massive problem as I have to open up fully and over expose to a degree the shot is unusable at that exposure to make it happen

 

but yes it does occur!!!

 

 

 

edit:  Ive only been able to get the Blue spot once , despite just trying now in bright sunlight , I cant get it to do it again....so dont worry about it , its a freak occurance under certain conditions

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Hi, could you post some sample photos/videos so I can see how this lens performs? Also could you tell me how its ergonomics are?

 

Angenieux and Tokina are identical lenses optically

Tokina is all metal , internal focus and internal zoom  like propper lenses should be, , nothing extends out so your Matte Box fits on the end all OK

its big and heavy and needs a rig all the time , do not hand hold this lens with no rig.

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Can anyone tell me whether or not I can use Nikon lenses which have aperture rings on lens turbos that have aperture control?

lens turbo does not have apperture control , its a lump of glass in an adapter , no iris

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This trick will be useful on the cheaper Chinese RJ Jinfianance speedboosters as they are a bit softer than the Mitakon Lens Turbo

 

Funny, if you search around the internet for those who've used both, the RJ lens turbo is generally said to be the more expensive and sharper version. The mitakon is a branded version of the no-name Chinese adapters that are all over ebay. I've been following this for a while, and trying to figure out if the extra sharpness on the RJ is worth a few extra bucks or if it is largely unnoticeable in video. You are under the assumption that the opposite is true, it seems.

Hey Andy, does the Mitakon still have the blue spot problem or have they cured it?

The new RJ versions have largely cured it unless you are going super wide. I had a conversation with RJ (he's super nice and very responsive, a great guy to talk tech with and knows his stuff), and he told me that with the latest batch, the blue dot only appears with super wides like the tokina 11-16. Some of the Mitakons may have repaired this as well, but it will depend on which batch you get (ebay is a mixed bag from different runs, according to tests in other forums).

 

lens turbo does not have apperture control , its a lump of glass in an adapter , no iris

 

Wrong again, unless the Mitakon is again inferior to the RJ version:
65a373f2d888d5458fcd27230db37d.jpg

 

The EOS version does not have aperture control (as any simple adapter wouldn't, it is electronically controlled). But the FD and Nikon version have that open/close blades switch for manual adjustment that are common on these adapters. 

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Dische

 

 

the Mitakon Zhongyi Lens turbo I just got today does NOT HAVE AN IRIS !

 

its a lump of glass in an adaptor no rings to turn or anything for Nikon apperture control

 

http://mxcamera.com/mitakon/en/index2.html

 

http://mxcamera.com/product_info.php?products_id=861&osCsid=ace1342e0320aab80c551104777b6bf4

 

its is not the generic speedbooster on ebay , it came direct from the manufacturer

 

and from the tests I saw before I bought it conducted by Brian Caldwell of Caldwell Photographic who invented the original Metabones Speedbooster it is clear to see the Mitakon Zhongyi Lens Turbo it is better than the RJ version in these tests

 

http://www.dpreview.com/forums/post/53156458

 

http://www.dpreview.com/forums/post/53156458?image=0

 

now to my eyes in the center tests the Mitakon Zhongyi Lens Turbo out performs the RJ version , and I happen to like my images to have a sharp center!!!

 

it also looks nothing like the RJ version its a completely different case casting and possibly glass too.

 

Lens Turbo is a trade name of Zhongyi which is associated in some way with Mitakon who are a Chinese lens manufacturer

 

 

any how all that is piffle , the Lens Turbo for me is very good and does the job superbly I will be using it alot from now on.....nuff said!

 

 

next on my list is the EF version

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Dische

 

 

the Mitakon Zhongyi Lens turbo I just got today does NOT HAVE AN IRIS !

 

its a lump of glass in an adaptor

 

http://mxcamera.com/mitakon/en/index2.html

 

http://mxcamera.com/product_info.php?products_id=861&osCsid=ace1342e0320aab80c551104777b6bf4

 

its is not the generic speedbooster on ebay , it came direct from the manufacturer

 

and from the tests I saw before I bought it conducted by Brian Caldwell of Caldwell Photographic who invented the original Metabones Speedbooster it is clear to see the Mitakon Zhongyi Lens Turbo it is better than the RJ version in these tests

 

http://www.dpreview.com/forums/post/53156458

 

http://www.dpreview.com/forums/post/53156458?image=0

 

now to my eyes in the center tests the Mitakon Zhongyi Lens Turbo out performs the RJ version , and I happen to like my images to have a sharp center!!!

 

it also looks nothing like the RJ version its a completely different case casting and possibly glass too.

 

Lens Turbo is a trade name of Zhongyi which is associated in some way with Mitakon who are a Chinese lens manufacturer

 

 

any how all that is piffle , the Lens Turbo for me is very good and does the job superbly I will be using it alot from now on.....nuff said!

 

Andy-

None of these adapters have an iris (as in, the fake aperture blades that some EOS adapters have adopted to let you change f-stop on a Canon lens). However some of them have a lever to control the len's iris where supported. 

You are correct, however: it appears that the Mitakon version does not. Which seems like a severe downside in my opinion! I love having stepless aperture changes and the ability to use modern adapted glass. The RJ FD and Nikon adapters do.

I've seen those tests from Mr. Caldwell, they have been discussed to death on other forums (lets just say that a certain Vitaliy has some pretty harsh opinions of Brian's test being biased). I do find it very interesting that Caldwell's test is one of the only ones that seem to suggest that the RJ adapter is inferior. Most of them report the RJ being of higher optical quality, especially regarding edge sharpness (where the Mitakon really falls apart on every test I've seen except for Caldwell's). 

Also understand that RJ's adapters had an update, as I understand it. Perhaps he was testing the initial batch which has since been fixed. Either way, I'm just reporting what I've researched and came to a totally different conclusion than you did. 

As far as the name is concerned- I've seen no less than three products referred to as a "Lens Turbo", including RJ's. Not sure if it is an officially registered name to anyone, but I could be wrong. :)

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anyhow the one I have is very good I do like it alot , it works nicely , faster, wider, sharper .....all good things to have

 

Ive just looked they do sell it on ebay too here

http://www.ebay.co.uk/itm/Mitakon-Lens-Turbo-Focal-Reducer-Adapter-Nikon-Ai-s-to-m43-MFT-Olympus-camera-/111334817179?pt=UK_Photography_CameraLenses_Lens_caps_hoods_adaptors_ET&hash=item19ec127d9b

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