My Roxsen Focal Reducer/ "Speedbooster" clone arrived today

[RnR]

That stinks.
Maybe someone can hack together one from a regular AR adapter and a cheep Speedbooster for something else.

Hmmm, there's an idea.

I think someone here on the forums printed one... and used the optics from a Metabones Canon FD/m43 Speedbooster.

 

[Minniesmum]

Depends on how you look at it. (This is my understanding.)

Let's take an example...

You're shooting a portrait of person, without a focal reducer.

If you add a focal reducer and retake the shot, without repositioning the camera or the subject, you would essentially see no change in the depth of field. You would have a wider field of view, and more light hitting the sensor, but the depth of field is unchanged. You could, in fact, create the same image you got without the focal reducer by cropping the image you got with the focal reducer. In this sense, no, you don't get more bokeh.

HOWEVER, because you get a wider field of view, you CAN reposition the camera closer to the subject to create the same framing as the original shot. And because now the distance between camera and subject is reduced, the depth of field decreases -- or put another way, there's more bokeh. So in this sense, a focal reducer can create more bokeh, or at least the opportunity to create more,

Totally agree and this is what I've found . You get an extra stop of light and a full-frame view but the perceived depth of field remains the same- the bokeh may change a bit as in more swirl tho. As someone pointed out, no miracles with them - but for me a bit of fun, which is why I've gone for the Camdiox ( Roxsen ) cheaper version

 

[RDM]

I think someone here on the forums printed one... and used the optics from a Metabones Canon FD/m43 Speedbooster.

That sounds cool.
I have access to several 3D printers.
I wonder if he would share the drawing file.
Guess I'll have to look for the post.

 

[Timur]

I could be wrong, but I think the speed boosters do not offer a "Full frame FOV", rather they offer a APSC one, which is still pretty cool. I'm currently waiting for my Helios 44-2 to arrive, and in the meantime looking at those speed boosters / focal reducers, because I want that swirly bokeh, and seems it doesn't not appear as clearly on MFT sensors. I've some very cool images from pentax forums though

So I read the entire thread here, and what I gathered is that Roxsen / RJ / Camdiox are all the same model, just rebranded? So there's no particular difference between those in performance?

I'm also looking at the newer Zhongyi (aka Mitakon) adapter, but I can't find any reviews for the newer MFT model yet.

However, this was an interesting read
Micro Four Thirds Focal Reducer Shootout: Micro Four Thirds Talk Forum: Digital Photography Review

Seems Zhongyi is a better (although slightly more expensive) option, and they've just released Ver II of the adapter few months ago, I'm hoping they fixed the optical issues that the Ver I sometimes displayed.
Anyway, I guess it'll be a leap of faith of sorts, and unless you're buying a Metabones one, all of the cheaper options have their issues.

 

[spatulaboy]

All the x 0.71 reducers give you an APS-C view on m4/3. They will give you a FF view on an APS-C camera.

Metabones has a Speed Booster XL that gets a 0.64 crop, which is not notable for stills photography, but important for video because it gives you an exact equivalent to Super 35 film.

 

[Timur]

All the x 0.71 reducers give you an APS-C view on m4/3. They will give you a FF view on an APS-C camera.

Metabones has a Speed Booster XL that gets a 0.64 crop, which is not notable for stills photography, but important for video because it gives you an exact equivalent to Super 35 film.

Yup, i meant on MFT. Why isn't 0.64 crop not notable for stills? Is it not sharp enough for stills?

 

[skellington]

Totally agree and this is what I've found . You get an extra stop of light and a full-frame view but the perceived depth of field remains the same- the bokeh may change a bit as in more swirl tho.

The depth of field IS the same, as is the bokeh.

Let's say you put a sensor down on your desk that is m4/3 sized, and then manually hold the lens above it, so it projects an image onto the desktop.

If it is a m4/3 lens, it would barely cover the sensor.

If it is a full-frame lens, you have a much bigger image, and most of that image shines on the desk around your sensor. But the sensor in the middle of the image takes the EXACT SAME picture as a full-frame camera would, but you only get the middle part. (Just like if you cropped a shot from a DSLR.) So the depth of field, bokeh, etc. is precisely identical. (Cropping does not change depth of field, bokeh, etc.)

A focal reducer narrows down that image from a large circle to a smaller circle on your desk. Still larger than what it takes to cover a m4/3 sensor, but more of the image is on the sensor. However, they're just designed to change the size of the circle (and in the process make it more concentrated/brighter.) They don't actually change any of the focusing or characteristics of the image (other than introducing some amount of additional blur/distortion/reduction in sharpness.)

So a focal reducer is just cropping a larger part of the image. Again, cropping doesn't change depth of field, bokeh, etc.

 

[RnR]

The depth of field IS the same, as is the bokeh.

Because the focal reducer 'widens' the view, you can now get closer to the subject and get the same shot... just with more subject isolation.

However, they're just designed to change the size of the circle (and in the process make it more concentrated/brighter.) They don't actually change any of the focusing or characteristics of the image (other than introducing some amount of additional blur/distortion/reduction in sharpness.)

The image circle is compressed, or said in another way, the signal is packed into a smaller area. This is why a decent focal reducer will show a nice increase in sharpness. Not a reduction in sharpness.

 

[TNcasual]

Reviving an old thread.

I was wondering if anyone has any additional comments on the Roxen/RJ focal reducers. Is Ebay from China still the only way to purchase these? And what about the Zongyi ones any experiences with those?

@Minniesmum ; @kevinparis

I am considering getting a m42 focal reducer. I like my Super-Takumar 50 1.4, but being a nifty 50 it overlaps with my Nikon and Leica 50s. I was thinking making it a 36 1.0 might be a nice way to give it life.

 

[Machi]

I was wondering if anyone has any additional comments on the Roxen/RJ focal reducers. Is Ebay from China still the only way to purchase these?

I have Camdiox Canon FD focal reducer from the UK (Ebay) and I think that it's the same as Roxen. It even has "Roxsen" written on some parts of packaging.

 

[TNcasual]

I have Camdiox Canon FD focal reducer from the UK (Ebay) and I think that it's the same as Roxen. It even has "Roxsen" written on some parts of packaging.

Any comments on it? Examples from it?

 

[ijm5012]

I have an RJ / Roxsen focal reducer for FD to m43. It did make a difference in the exposure, delivering the promised extra stop of light. However, I didn't notice any real improvement in terms of sharpness. I only paid something like $50 or $75 for it, so it's not a big loss.

I no longer have any FD glass as I've sold it all and instead moved to using the f/0.95 Noktons. IMO, the Noktons perform better at wider apertures than the FD glass on the 3rd party speedboosters. From what I can tell, the optical performance is indeed better when using an actual Metabones instead of a 3rd party one, but that comes at a much greater cost as well.

 

[Machi]

Any comments on it? Examples from it?

I didn't properly test it but my experiences are similar to @ijm5012's. I'm using it with Canon FD 50mm f/1.4 and it works nicely.
Here are two examples which I already posted here, first one is at or close to full open aperture, second one is at f/5.6 (4 with reducer).

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[ijm5012]

Yep, like @Machi I used it with an FD 50/1.4, as well as a 24/2 & 100/2.

Sharpness didn't really improve with any of the lenses. The 50 & 100 were already incredibly sharp. The 24 was pretty darn good, but not up to the same level as the other two. The 3rd party "speed boosters" allowed for higher shutter speeds and did alter the focal length, making them wider. However, I didn't see a sharpness improvement.

If you're happy with the sharpness of the lens, then I'd say go for a 3rd party one, because it does allow the lens to be shot with a faster shutter speed, and it does make the FoV wider. But, if you have a lens that's pretty good sharpness wise, and you think it'll be better with anything other than the speedbooster (the one by Metabones), I think you may end up disappointed.

 

[Machi]

There is one flaw which I forget to mention and it is also inherent to 1.gen Zhongyi focal reducer.
It's blue spot caused by internal reflections in case of bright light. But even in bright light it could be treated by proper framing
so it's not big problem.

 

[retiredfromlife]

Are there any recommendations for speed boosters or focal reducers for Minolta MD to Mu43 ?
I would like to try on of these

Regards

 

[Machi]

Are there any recommendations for speed boosters or focal reducers for Minolta MD to Mu43 ?

I don't know if there is a Zhongyi focal reducer for Minolta MD->M43 but there is one from Metabones and from Camdiox/Roxsen.
What I saw it's generally accepted that those from Metabones are the best (and most expensive) and Camdiox/Roxsen are the worst (and cheapest) from those three.
But as you can see on this page, even the worst are still pretty usable.

 

[Klorenzo]

Any comments on it? Examples from it?

I have the Roxsen, got it from ebay UK. I can post a few samples but obviously it changes a lot depending on the adapted lens. All the lenses I used (Nikon Ai-S, series E) wide open are soft and with little contrast. With the FR this does not improve.

Anyway, in this album there are a few formal test shots with the Nikon Ai-S 50/1.4:

https://www.flickr.com/gp/133025950@N04/F0NQ51

and wide open...it's terrible (at 100% crop).

At the same time in the real world it's not bad at all (especially stopped down but then...what's the point?), I've used it in a dark church ceremony with good results.

Full size on flickr, some of these are wide open:

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What focal lengths do you have in mind? Somewhere I have a few samples with a 200/4 and was not bad, just useless.

BTW, I'd love to see a Nikon 105/2.5 with a focal reducer...

 

[retiredfromlife]

I don't know if there is a Zhongyi focal reducer for Minolta MD->M43 but there is one from Metabones and from Camdiox/Roxsen.
What I saw it's generally accepted that those from Metabones are the best (and most expensive) and Camdiox/Roxsen are the worst (and cheapest) from those three.
But as you can see on this page, even the worst are still pretty usable.

Thanks for the reply. I notice the Metabones in Australian stores but they are $600.00 plus.
I will check out the out the two online

 

[TNcasual]

My idea was to use it for my m42 Super-Takumar 50 1.4.