AR Farm Gal Loc: Piggott, AR (NE AR)

Has anyone used a Viltrox or Canon speed booster on the Canon R7? I see it mentioned in several YouTube videos.

Also, will my Canon 100-400 Mk II be terribly heavy for my new R7? I have a shipping notification, so my R7 will be here in just a few days.

I have some good EF L glass, so my plan is to use that for awhile. From what I'm seeing, the speed booster can give about a 1.1 vs 1.6 crop factor. I want to use longer lens with just an adapter, but I would like to try using the speed buster with some of my wider lenses. Thoughts?

User ID

While it will be functional, you should consider that it is essentially a video specialty accessory such that you can encounter some frustrations for stills.

Architect1776 Loc: In my mind

Your 100-400mm will not be heavy for the R7. It can handle the 800mm and 1,200mm lenses just fine so the 100-400mm MII would be no problem. The R mount also appears to be even more robust than the EF mount if that counts.
Obviously it would not be recommended to swing any large lens around by just holding the camera but if you were to just hold the camera the lens will not bend or break at the mount, it is not advisable though for many reasons.
Speed booster, I do not know.

AR Farm Gal Loc: Piggott, AR (NE AR)

Thanks!

User ID

Speed Booster is a quite different animal.

amfoto1 Loc: San Jose, Calif. USA

A speed booster (also called an "accelerator" or a "turbo") is essentially the opposite of a teleconverter.

A teleconverter has optical elements that increase a lens' focal length. For example if you put a 1.4X teleconverter on your 100-400mm lens it will "become" a 140-560mm combo. It also will "lose" one stop of brightness. Where your lens is f/4.5-5.6 on its own, with the 1.4X added it will "become" an f/6.3-8. This makes sense when you think about it, because f-stops are the relationship between the focal length and the size of the lens aperture. When a 1.4X teleconverter is added to a lens, the focal length is increased, but the aperture within the lens remains the same size. (A 2X teleconverter "loses" two stops of light. A 3X loses three stops. A 1.7X loses 1.5 stops.)

A speed booster uses optical elements to decrease a lens' focal length. Most speed boosters are 0.7X, which would make a 50mm lens into a 35mm. It also "adds" a stop of brightness, in a sense. So if that 50mm were an f/1.4, with the booster added it will behave as a 35mm f/1.0. This can be proven with a little math. The "f" in f/1.4 stands for "focal length" and the "/" means "divided by" or makes this a fraction. So if the focal length is 50mm and you divide 50 by 1.4, the result is approx. 35. In other words, the actual diameter of that lens aperture is 35mm (actually slightly more, but close enough). Now when the 0.7X booster is added the lens focal length changes to 35mm while the diameter of the aperture remains the same... 35mm focal length with a 35mm lens aperture is f/1.0 or "35 divided by 1 = 35".

Speed boosters are primarily used for video and less often used for still photography. The reason is image quality. Both teleconverters and speed boosters use optics to modify the lens focal length. This can effect image quality. Very good but expensive teleconverters and boosters will have minimal effect on IQ... but more "affordable" ones that use lower quality optics will show more effect on IQ... possibly softening images, reducing fine detail and having other negative effects. With video the losses are not particularly noticeable or are worth the benefit of a speed booster's wider angle views and shallower depth of field effects may be worth the losses. But with still photography the losses in IQ may be too great and the benefits just too little.

I would recommend a plain EF to RF adapter instead, if your primary use will be still photos. The types of still photos done with short focal length, wide angle lenses are usually full of detail and stopped down for deep depth of field... neither of which is helped by a speed booster.

Canon themselves make several different EF to RF adapters:

- a plain adapter
- an adapter with a user programmable control ring
- a couple different versions with drop in filters.

Only the last of those have any optics in them, and in the case of drop-in filters it's a plain, flat piece of glass (still needs to be good quality, of course).

All these types of EF to RF adapters are now being offered by various 3rd party manufacturers such as Fotodiox, Vello, Commlite, Viltrox, Meike and others. Because they are mostly just spacers and the electronics are simple pass-throughs, it is probably pretty safe to use these. Do be a little careful though... the bayonet mount and latching mechanism might not be as robust as on Canon. Of those brands, I've got Viltrox and Commlite adapters that appear equal to Canon's own in this respect and work fine (mine are not EF to RF, but other types of adapters).

Looking at B&H website, I see three 0.7X speed boosters selling for $268, $479 and $529!

Plain EF to RF adapters sell for between $59 and $99. Control ring adapters cost $88 to $199. And drop-in filter adapters cost $149 to $399.

Wide angle lenses can be expensive, but there also are some that are more affordable than a speed booster. Some examples:

- TT Artisan 11mm f/2.8... $215 (full frame, manual focus, manual aperture).
- Canon RF 16mm f/2.8... $299 (full frame capable, autofocus).
- Venus Laowa 10mm f/4 "Cookie"... $299 (APS-C, manual focus/aperture, coming soon).
- NiSi 15mm f/4 Sunstar ASPH... $399 (full frame, manual focus/aperture).
- Venus Laowa 14mm f/4... $489 (full frame, manual focus/aperture).
- Canon RF 15-30mm f/4.5-6.3 IS STM... $549 (full frame, autofocus, coming soon).

There are more all the time and there are also some fisheye lenses. Many of the above are manual focus & aperture, which may be a concern. I use a 12mm manual focus/aperture lens on another system and find it no problem with a wide angle lens where depth of field is very deep and precise focusing just isn't all that necessary. If wanted it also is still possible to have auto exposure, even with a manual aperture. Just select that aperture and set the shutter speed while using Auto ISO.... Or use Aperture Priority AE (don't use Shutter Priority or Program AE).

Barbonbrown

Having used Viltrox speedboosters for a number of years, albeit on M4/3 cameras, with some excellent vintage glass from Canon, Nikon, Olympus, Pentax, etc, I cannot necessarily agree with the suggestion of a material effect upon image quality. It very much depends upon the make. Compared to the images obtained using dumb adaptors with the Viltrox there is little or no reduction in quality. The advantages of increased speed and reduction in focal length make them a very good addition to the kit bag. I print up to 2 feet x 3 feet so any effect would be easily noticeable.

For the price, around £110 in the UK, the Viltrox is excellent. The Metabones is far more expensive, having seen how good the Viltrox performs I'm unconvinced the extra money would be worth it, but it is certainly a quality product.

I've tried other brands too, they have degraded the IQ.

I have to agree about teleconvertors though. Some have been very disappointing, though some few, the Olympus ones designed specifically for particular lenses, are excellent and simply do the job with no IQ drawbacks. (Doubtless Canon, Nikon etc versions would perform as well too).