Advice requested re Canon 1.4 extender

[Wandalynn]

I already had a Canon 1.4x mark I extender when I recently bought a Canon 100-400 L II lens. The mark I extender seems to work fine with it but should I spring for a mark III extender for this lens? I had been using the mark 1 extender with the similar-vintage Canon 300mm f4 L. Cameras are EOS R and 90D and I shoot mostly butterflies, bees, and smaller nature--not many birds. Thanks.

[ebiggs1]

"The 100-400mm II is razor sharp, even wide open."

That is what I have heard.  However, not interested. Two reasons and they both begin with Sigma.

[PLC3]

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@Waddizzle wrote:

Sounds like a good reason to simply remove the filter, and go without one.  If your images were still not to your liking, then the problem was the lens, not the filters.

I could not get sharp images with the 100-400mm II until I removed the UV filter, and set Image Priority to FOCUS.

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Newbie question:  What do you mean by "...set Image Priority to FOCUS."?

[Waddizzle]

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@PLC3 wrote:

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@Waddizzle wrote:

Sounds like a good reason to simply remove the filter, and go without one.  If your images were still not to your liking, then the problem was the lens, not the filters.

I could not get sharp images with the 100-400mm II until I removed the UV filter, and set Image Priority to FOCUS.

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Newbie question:  What do you mean by "...set Image Priority to FOCUS."?

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What camera are you using? I do not think Rebels make that setting available.

[ebiggs1]

"What do you mean by "...set Image Priority to FOCUS."?'

It is not necessary. Setting and using just the center focus point and 'One shot' for most of your photos will work best.

[wq9nsc]

Optically, I really don't think you are going to be able to tell a difference with most combinations between your original and the latest version.  If you didn't have an extender and wanted one, then getting the newest one makes sense but I wouldn't move to the newer version from what you current are using.

An extender is always going to reduce the image quality of the native lens, with a really good lens that can be acceptable.  But with the current high pixel count sensors, in many cases cropping is going to work as well or better.  If the lost f stop from the extender forces you to an exposure triangle where the ISO is set more than a stop or two from native then the quality may be lower from the combination than cropped.  The other option with the extender is dropping shutter speed to compensate but again the loss due to motion blur may exceed any gain from the extra 40% increase in image "fill" of the sensor.

I have taken a lot of test images with my EF 300 and 400 f2.8 lens with a 1.4X in place and I shot one soccer game with the EF 300 1.4X combo while my EF 400 was in for a checkup.  The images are very nice because the bare glass is so good but even with these the loss between bare glass and using an extender is obvious.  If you consistently need an extender on a lens, then you really need longer glass instead of a newer extender.

Rodger

[Wandalynn]

Thank you everyone for your input and sample photos. It gives me some good points to look further into. And to see if I know someone who has a mark III that I can try out.

[wq9nsc · Accepted solution]

Doing a test with the version iii extender would be the best way for you to decide if the upgrade is worth it for you.

With current sensors, you really have to decide whether you are better off cropping versus using an extender.  I am going to be shooting some outside stuff later today and for fun shot the same subject from the same distance using an EF 400 f2.8 IS II with and without the version II 1.4X extender.  Here are a couple of comparison shots below with the bare lens cropped to basically the same subject size for both conditions.

The EF 400 f2.8 is one of optically sharpest lenses Canon makes so even with the degradation via the extender it is still sharp but the results are noticeable.  This was using my 1DX III, the same setup with my 5DS R would likely bias the results even more towards cropping.

Just a little more data to help you decide whether it is worthwhile to upgrade from an early to later version of an extender.  The better high ISO performance of newer bodies helps offset the old problem of losing a stop with the 1.4X but with the denser/higher MP sensor it makes cropping a much more viable option also.

First image is bare EF 400 f2.8 IS II, the second with the 1.4X and both were shot from exactly the same location.  The last image shows why the loss of depth of field is a drawback to the use of the extender, only about a 3" loss for this combination at the distance I was shooting but if I had used the extender with the last image it would have been an issue.

Rodger

[Wandalynn]

Rodger,

Thank you so much!! Excellent points and fabulous images to illustrate them. Wanda

[wq9nsc]

You are welcome Wanda and I hope it helps you with your decision making.

My first digital was an EOS 1D Mark II with an 8.2 MP sensor and I found the 1.4X extender to be very useful.  With my 1DX II and III and 5DS R bodies I find that the difference in final quality between heavier cropping with a bare lens and using an extender is far closer and this is with very sharp primes, generally the drop in sharpness is going to be more significant when pairing a zoom lens with an extender making a 1.4X vs cropping an even closer decision.

There are certainly cases where a 1.4X will work quite well, particularly if the loss of one stop and the slowing of AF speed is acceptable.  In really good lighting, a converter can produce very nice results but under less optimal conditions the 1.4X makes them even less optimal. 

With a high pixel count sensor, cropping works very well if you can keep the ISO in the lower range.  The slight increase in depth of field can save you at times because if shooting sports or wildlife the AF point isn't always exactly where you would have liked it and a little extra DoF gives you a sometimes image saving fudge factor.  With landscapes and portraiture you can take the time to get the shot perfectly set up but trying to do that in other environments often means you missed a killer shot by 100 milliseconds which means you completely missed the opportunity.

I believe any image quality improvement between your current 1.4X and the new one would require extreme pixel peeping to see.  I would put these to the same test as those who try to sell expensive audio patch cables, if the difference isn't readily apparent then your money is probably better spent towards another useful lens or other item that will give you greater benefits for the work that you do.

Rodger

[PhotoGerry]

I'm wondering were the forcus points might be in the first photo.  Could you use AF with the 1.4X in the lens stack?   

Thanks in advance,

G