BassmanBruce Loc: Middle of the Mitten

I have the above lens and use it with a 1.4x tc on a A7r iii with very good results. Any image degradation is to small for me to even notice and AF still works like a champ.
I am thinking of adding the 2x tc but wondering how much of a hit IQ will take and how much another stop of lost light will affect AF.
My question is for anyone who uses this combo, what has been your experience?
Any reviews I have found online were pretty worthless.
TIA!

Nalu Loc: Southern Arizona

I personally have not tried the lens with a 2X converter, probably because of loss of light and the implications of pretty high ISO’s to accommodate that, and the fact that I like to keep my shutter speed up because I shoot mainly birds. But, I can say that Arthur Morris (Birds as Art), although I don’t recall specifically, has posted images taken with this lens/extender combination attached to his A1, that demonstrate that it can be done with good to excellent results. For the most part, I used Sony’s excellent converters on my prime lenses (faster) and to me (compared to previous use of such on Canon DSLRs) provide excellent results. But I should also say that I have used the 2X quite a bit on the second version of Sony’s 70-200. Shooting at 400mm with such a small light lens is a treat. So, considering we know the 200-600 has excellent optics and the 2X converter is extremely sharp as well, the combination has the potential to put out some really good images but with very good operator techniques. I’d go for it and good luck.

CHG_CANON Loc: the Windy City

Doubling the f/6.3 widest aperture at 600mm for this lens is greater than f/11 due to the loss of light reaching the sensor through still more distance and glass. Does the manual for the Sony a7RIII speak to the minimum (effective) aperture needed for the AF to function? Do the specs for the lens and / or 2x TC speak to cameras were AF is retained at smaller than f/11?

Mirrorless bodies are not bound by the older limitations of DSLRs, where typically f/8 was the limit. But, out on the bleeding edge of mirrorless technology, these things still need to be investigated and confirmed for each specific body and lens combination.

imagemeister Loc: mid east Florida

IMO, AF will take a speed hit and you will loose a stop of ISO. Can your body afford the ISO hit ?? ISO impacts sharpness in addition to physical optical TC sharpness loss. OTOH, you could crop and use pixel enlargement saving ISO, weight, and $$$ .......

You could also use Sony's CIZ to get to 1200mm by shooting JPEG - here is a link to my posting of this with RX10m4 - https://www.uglyhedgehog.com/t-749907-1.html Do the download

With any crop / pixel enlargement scenario, optimization of native IQ will be critical ...for best results
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CHG_CANON Loc: the Windy City

At 42MP in the Sony A7Riii, the suggestions to get closer and / or crop might be more effective than using the 2x TC.

UTMike Loc: South Jordan, UT

I have and use the 1.4 and 2.0 tc with the lens you mention. You need great light and a steady perch. I would stay with your 1.4 unless you have a good tripod and light.

gwilliams6

PDAF focus on the A7RIII is down to f8, but the camera will still do CDAF below that f-stop so you can still use AF.

Later models do PDAF all the way down to f22. CDAF has always been at all f-stops.

Here a couple of A9 shots with the Sony 200-600mm f5.6-6.3 lens. both shot on Brookings Lake, Manistee National Forest, Michigan, USA.

1) A9, 1.4X TC, 840mm, kids pulled behind a fast speedboat, handheld shot

2) A9, 2X TC, 1200mm Jetskier on same lake, shot from shore, handheld shot.

I would say you may lose about 10-15% image quality with the 2X TC on this lens, still acceptable IMHO.

FYI, I have owned Sony A6500, A7RII, A7RIII, A7III, A9, and currently own Sony A7RIV, A1, A7SIII. My Sony 1.4X and 2X TCs have been used with my Sony 70-200mm f2.8 GM lens and my Sony 200-600mm lens with very good results, sometimes requiring higher ISO for fast shutter speeds.

Cheers and best to you.

(Download)


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billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

I highly NOT recommend that. You loose light to a point that effects your focusing speed. You also suffer image quality.

Canisdirus

No idea what lens you are using...but a 2x is the last accessory you should be looking at.

Reach is needed but not the end all...and if you are going to use native body and native glass....you better invest in the native tele...not some knock off...which means Sony...which means 500 bucks.

The last accessory you should be considering. You are better off cropping most of the time anyway.

BassmanBruce Loc: Middle of the Mitten

A Big thanks to all who chimed in! As much as the lure of xtra reach sings to me I have decided to stay with my current 1.4x tc.
Again thanks!

bwana Loc: Bergen, Alberta, Canada

I use a 1.4x TC with the FE200-600 on both an A7 III and A7R III (and soon an A7R V) with good success. 840mm focal length is probably the most I will ever need. I considered the 2x TC but decided against it.

Just my thoughts on the subject.

bwa

Karl's Bird Photography Loc: Oregon

I have a Sony a7r4, 200-600, and 1.4 TC. I believe the 61mp are a little too much for the 1.4 to work perfectly so I usually end up not using the 1.4 unless the light is really good. I can see a very slightly less sharp image using the 1.4 TC. Best thing is to test it out to see for yourself how you like the results.

SuperflyTNT Loc: Manassas VA

Yeah, the reason DSLR’s can’t focus at higher f-stops isn’t about light but about those apertures limiting the angle at which light is directed to those phase detect focus sensors. With mirrorless as long as there’s enough light it’ll focus but the speed will probably suffer.