MTF B4 to E-Mount adapters
 

I have a few questions and hopefully Chris Young will find this thread?

There are two MTF B4 to E-Mount adapters.

One here is simple and goes right to e-mount but does not talk about 2x extender on the B4 lens. Instead it says you have to go into center crop on the FS7. Seems like less options then the next one. Or am I missing something?
https://www.lensadaptor.com/b4-23-su...-mount-adaptor

This one says you need to use the 2x extender, so can you shoot 4K with the extender on? Since center crop above will only be 1080?
https://www.lensadaptor.com/b4-23-sony-e-mount-package

Re: MTF B4 to E-Mount adapters
 

Paul

MTF offer two different B4 units. The first one, which I used to own comprises of two pieces. The first piece is B4 to Canon EF which adjoins the second piece which is EF to E-Mount. This original unit has an optical group in the front B4 to EF segment. This lens group delivers a 0.5 magnification. Using this combo you have to use a B4 lens with a build in 2 x converter.

Remember an HD sensor in 16 x 9 mode has an image circle of 11mm. A B4 lens with its 2 x engaged delivers an image circle of 22mm. Add in the MTF adapters 0.5 magnification of 5.5mm and you end up with an image circle of 27.5. The Sony F5/FS7/FS5 sensors have an image circle of 27.1mm. Therefore you can use the two piece adapter on a 2 x B4 on the above cameras and shoot using the full sensor instead of the crop function or Clear Image zoom in the case of the FS5. Using this 2.5 x setup causes a 2.5 F stop light loss. 2.5 stops even on the FS7 in low light situations is a fair loss. Depending on the prime aperture of the BF being used you end up with a B4 with a prime aperture of between F4.0 and F5.6. The original two piece unit was conceived by Alistair Chapman in conjunction with Mike Tapa from MTF Services. See here:


For me this 2.5 stop light loss limited the HD shoots the FS7 could be used on so when the FS7 S16 center crop firmware came out I went for the S16 unit with its 0.8 eight light loss. With the full frame adapter you could actually shoot 4K if you wanted to but as yet I have not found a B4 that will deliver what I would call a really decent 4K image. In HD the full frame unit delivered a pretty decent picture but in my opinion not as good as the S16 unit. Any benefit of using the 4K to 2K down sampling of the FS7's full frame sensor seems to be lost after you push the image through so much glass. To expand an 11mm image to 27.1mm is a big stretch by any means. With the S16 adapter you have an image stretch of 32% in center crop. With the original two piece full frame adapter you have an image stretch of 250%. That is a very big difference.

After seeing the results I was getting a colleague of mine was able to pick up a used IBE HDx1.4 converter which also works very well. It's designated 1.4 because it does indeed magnify the image by 1.4. A 1.4 x magnification causes a 1 stop light loss. All the IBE units are really well made pieces of German kit.

https://www.ibe-optics.com/en/cine/o...verter/hdx1-4/
https://www.abelcine.com/buy/lenses-...ptical-adapter

Abakus in the UK also make a B4 to S16 1.32 x adapter called the Abakus132 Converter. Available as E-Mount. This was the unit I rented first off that got me interested in B4 solutions.

http://www.abakus.co.uk/B4toPL.htm
https://www.bhphotovideo.com/c/product/580779-REG/Abakus_120_132_Converter_Lens_B4.html/BI/2855/KBID/3801

Also worth a look is Doug Jensen's comprehensive video on the quality of the Sony center crop vs full frame:


Hope this helps!

Chris Young

Re: MTF B4 to E-Mount adapters
 

Chris,
Appreciate all the great information and your experience. I have checked out both videos, and have discussed it with Doug in the past. While shooting wildlife I have used the center crop on a Red PL 300 with great success. But for sports the MTF & B4 looks like a nice setup.

I will rent some gear and see what works best for me. First I will rent the 18-110 for a doc I am about to shoot, this could be great. Then I will rent the MTF mount and borrow a B4 lens and shoot some sports with it. Guess that is the only way I will know what is best for me.

Re: MTF B4 to E-Mount adapters
 

"Then I will rent the MTF mount and borrow a B4 lens and shoot some sports with it. Guess that is the only way I will know what is best for me."

My philosophy exactly Paul. Good luck.

Chris Young

Re: MTF B4 to E-Mount adapters
 

Appreciate your help Chris,

Will let you know how it goes.

Re: MTF B4 to E-Mount adapters
 

or use a decent zoom possibly with native AF and buy a Tilta Nucleus (and use the grip/handle with the control on the finger) which is wireless smooth and can be used on any lens. The marketing people (ALL of them) decided this already: no affordable servo zooms wide to tele and the few ones are WAY too expensive and yet with limitations (in purpose) : from manual only to jerky zoom. So it's not gonna happen. Better look at the tilta (ridiculously cheap for outstanding stuff in my opinion)

Re: MTF B4 to E-Mount adapters
 

Chris,
Have you tried to add an optical stabilizer in the system? I use to use the Fujinon all the time with B4 glass and at times use the Canon B4 lens with the gyro built in. They were huge help when I was shooting fast boats from chase boats. Couple of shots attached of the setups I used. Used with PMW-500 and F800.

Re: MTF B4 to E-Mount adapters
 

Yes Paul I have but not with the FS7. I used them plenty of times because for some twenty years or so I shot an enormous amount of material at sea for the Aussie Navy. First on SP then Digi and then on the PDW 700 and 800's. We used all of the Canon stabilization varients over the years. The unit that goes on the front, the B4 stabilized lenses and the unit you are showing. I don't go to sea for the navy now so don't shoot much material that requires that kind of stabilization. If I need stabilized shots for my corporate work I find the Z90 with the active stabilization engaged and a zoom thru wide angle adapter covers most requirements. Thinking about it Paul I see no reason why Canon's stabilized options shouldn't work on a B4'ed FS7. After all a B4 lens is a B4 regardless of what it is on. It should be just a matter of supplying power to the stabilizer units.

Chris Young

Re: MTF B4 to E-Mount adapters
 

Thanks Chris,
They do work very well. I found the Canon lens in my picture worked by far the best. Will hunt for the Canon as a rental, since years ago they would lend it to me for demo footage, but not the case now.

The Z90 is a great little cam. I have used mine for all my In and Out of the Boat Shop show the past year. Also looking at adding the Z280 as B-Cam which looks great. Lots of options.

Re: MTF B4 to E-Mount adapters
 

Yes the Z280 has got me thinking as well. Just have to justify it... as always :)

Chris Young

Re: MTF B4 to E-Mount adapters
 

Missing overcranking is the only thing that held me back right away. But an EX1 that does 4K at 10bit, 422 is hard to pass up. Hopefully Sony will add 120fps at 1080. It is still on my list for early 2019.

Re: MTF B4 to E-Mount adapters
 

Yes understood Paul, 4K 422 10-bit 50/60p. That's why I'm tempted by the spec of the 280. Funny you mention the EX1. Shot an industry awards presentation last night primarily for the big screens at the venue. Dug out the old EX3 with an ACM-21 and a 2/3" 22x lens as it was a long haul from the back of the venue to the podium stage area. Clients were very happy with the images out of the old beast. The EX3 is running my own personal settings to get the best out of the camera's dynamic range and tame the EX's tendency to want to blow highlights. Old now but it can still produce pretty decent images. A ten years old design for sure but the EX's were one of those designs that were pretty ground breaking in their time and well ahead of the rest of the game.

It's times like this that makes me think of the Z280 though I'm holding off for the moment. Secretly I'm hoping for a "Z300" or similar. Something with a proper side viewfinder and interchangeable lens but with the guts of the Z280. It could be based on the PMW-300 style or even the traditional ENG style of the PMW-320 / 500 style. If that gets announced at NAB I'm in.

Chris Young

Re: MTF B4 to E-Mount adapters
 

Chris, great memories of my EX1 and EX3 with the same setup as you mentioned. They were great cameras and I feel the FS7 is in the same great league.

Z280 with proper VF, overcrank, removable lens, would be a winner.

Re: MTF B4 to E-Mount adapters
 

Bring it on Sony! :))

Chris Young