R7 & EF24-105f4L Mk II with Viltrox Speedbooster (27-118 equiv. FF FL)

RDM5546 wrote:

RDM5546 wrote:

In some recent real world shoots I have learned a limitation of the Viltrox speedbooster with the EF24-105f4L and R7. I was surprised by this discovery that the 24-105 FL of the lens only works properly up to approximately 15 feet of subject distance from the camera when use the 24-40mm FL segment of the lens. I seemed to work and focus fine up the15 feet and also it seems work fine in the 40-105mm FL segment of the zoom lens.

For 24-40mm the lens will not autofocus beyond 15 feet! I could think of no reason for this to happen so I repeated attempt to focus farther away several times outside as well as inside my lit kitchen. I repeated trying several times to be sure. Autofocus seems to work consistently and correctly below 40mm when the range is less than 15 feet.

Odd!!

These are shots with zoom at 70, 35, 24mm FL. The autofocus subject is less than 15 feet away and camera/lens appear to be working correctly.

For the zoom set for FL = 70mm

For the zoom set for FL = 35mm

For the zoom set for FL = 24mm

The image at 24mm doesn't quite right. Maybe I will not using the speed booster with this lens. The other choices I have in RF lenses include the RF-s17-150, RF 15-35F2.8 , RF 24-70F2.8 and RF70-200f2.8 cover this same range without speedbooster's weirdness exhibited by the EF 24-105f4L for less than 40mm FL.

I should also mention that with this same camera and lens using a standard EF-RF lens adapter everything thing works properly at all FL and subject distances. The R7 and the EF 24-105mmf4L Mk II are not the cause of the anomaly. The odd behavior occurs only when replace the standard lens adapter with the Viltrox Speedbooster. I have successfully used the Viltrox Speedbooster with other camera and lens combinations and have only seen the problem with this particular 24-105f4L zoom of interest. Thought it's size, weight and aperture might make it a good candidate for using with the Viltrox.

I have other EF f2.8L zoom lenses with short zoom ranges that are heavier that may beneficially work with the Viltrox when I get around to trying them. Maybe even the 50-105mm useful range of this 24-105 will be attractive for some shoot in the future.

The use of the speedbooster with the EF24-105L MkII discussed above was disappointing to me and I doubt I will use this configuration ever again. The issue was that for some reason autofocus with the R7/Speedbooster/EF24-105L did not work (blue focus square was replaced by a red square!!) for FL 24-40mm at subject distance of 15 feet or more.

Today I used my R7/Speedbooster with my EF70-300f4-5.6L IS USM lens. I like this lens because it is an L lens and very sharp corner to corner. With the Speedbooster on the R7 the light is concentrated on the image area from whole lens so it becomes a f2.8-4 lens which is nice when there is lower light. I used this combination to shoot the same objects as I did with the EF24-105 that had issues.

I checked out close and far focus through the 70-300mm FL range and all worked perfect with the speedbooster attached to this lens. The field of view on the R7 with the speedbooster is unchanged at the same F.O.V. as a FF camera with a 70-300mm.

Picture of same plant as above using zoom set to wide end (70mm)

I took many pictures close and far. The R7 autofocus worked correct (blue square displayed, not red) for all values of FL and subject range.

Far away palm tree subjects with lens set to widest angle (70mm on the lens and 49mm equivalent field of view from using .71X Viltrox speedbooster)

This shows that at least some my L zooms lenses can be properly adapted using the R7 and speedbooster. The L senses are weather sealed and my RF-S lenses are not. I think that may be interesting in some harsher shooting situations. The R7 is a cheaper body and smaller than the R5.

I am still trying figure out all of cases where I prefer to use my R7 vs my R5. The use of speedbooster allows FOV of R5 with FF lenses to be what you also get when using the speed booster/R7. I have a bunch of FF EF L lenses to evaluate for use with R7 and the speedbooster.