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RF800mm F11 IS STM Images do not seem sharp...ringing around image

dcomora
Occasional Contributor

I am new to Canon products and recently purchased an R5 with the the RF 800 fixed f11 lens.  I have been shooting birds over the past few months.   I have been comparing my shots to those I see posted on line and it seems I am not able to get the sharp focus that I see others getting.  I am using the animal eye focus setting, I am shooting at  shutter speeds of  between 1000 and 2000, my ISO is usually never above 2000.   I have the image stabilization engaged and I most recently used a tripod.   When I zoom into my images, I see a little "ringing" around the outside of the birds and birds eyes.   Someone said I should use Topaz AI sharpen to get sharper images, but I am thinking that should not be necessary.  Is it possible that the lens is out of calibration or am I still doing something wrong?  I also have an R 25 - 105 lens and photos are super sharp. Any advice would be appreciated. 

40 REPLIES 40

rs-eos
Reputable Contributor

On a tripod, first try focusing on some non-moving object (ensure it has high detail in it) that would be around the same distance as the birds.   Are you able to capture sharp photos?

 

Also, what focusing mode are you using when capturing the birds?

--
Ricky

EOS 5D IV, EF 50mm f/1.2L, EF 135mm f/2L, 600EX-RT (x6), ST-E3-RT
EOS C70, RF 24-70 f/2.8L IS

dcomora
Occasional Contributor

Hi, Thanks for your input.  I am using the Animal Eye focus, which I have set up for back focus on the AF-ON button.  I also have spot focus on the "*" button which I use if I can't get the animal eye focus to catch or if it is stuck on the wrong subject.  Here is shot taken on a tripod of a very stil Jackalope. the specs are 8192 x 5464 (before crop).. size is 7.63MB, F11, exposure time 1/1250, iso 1250 also,  Used the animal eye focus.   In a post below I took same shot with R 24 to 105 lens and detail is great.  7B8A7554.jpg

kvbarkley
Honored Contributor

It could be heat shimmer.

https://www.kenrockwell.com/canon/eos-r/lenses/800mm.htm

 

Personally, I would not use eye detect. It really doesn't matter when you are 100 yards away!

 

dcomora
Occasional Contributor

I have tried manual focus, but I still dont seem to get very sharp detail. 

dcomora
Occasional Contributor

Just took a similar shot with the 800mm lens using manual focus and lining up the diamonds...on tripod.  still seems unclear. 7B8A7615  800mm manual focus.jpg


@dcomora wrote:

Just took a similar shot with the 800mm lens using manual focus and lining up the diamonds...on tripod.  still seems unclear.


I do not know why you switched to manual focus.  You've introduced human error into the equation.

 

But, how far away was your subject.  Your DoF should be narrow.  Take a look at the DoF in the f/11 column at various distance to the subject.  It is pretty narrow.

 

2AE5C39C-0210-4790-9ED6-A466252642E9.jpeg

------------------------------------------------------------------------------------------------

"Doctor told me to get out and walk, so I bought a Canon."

dcomora
Occasional Contributor

Hi, Thanks for this great information.  The reason I went to manual was a couple of the posts I received said they wouldn't use the animal eye focus, and suggested manual, which I think was worse than the animal eye.   I appreciate the chart and I have to say that I have been shooting for 2 months with this lens and I don't think I"ve gotten one shot that I am happy with, in terms of focus.  Many of my subjects were still or barely moving, lately all on a tripod.  I'm thinking about going to Unique Photo and renting the same 800mm lens and seeing if the result is better. .My only other lens at this point is the 24 to 105 and I am not seeing any of the ringing or ghosting around the images when I blow those images up....but I realize the depth of field is much greater. 

wq9nsc
Respected Contributor

I didn't see the answer to KV's question about how far you were from the subject but even at f11, the depth of field of an 800mm is very shallow unless you are a long distance away. 

 

The attached photo was shot with an EF 800 f5.6 and EOS 1DX III at about 40 feet with a usable depth of field of around 2" and it shows.  Even at f11, the DoF would be under 5" at that distance.

 

Rodger

 

AS0I3353.jpg

EOS 1DX M3, 1DX M2, 1DX, 5DS R, 1D M2, EOS 650 (film), many lenses, XF400 video

kvbarkley
Honored Contributor

It is always possible you got a bad one:

[Mod note: Removed link per Community Guidelines - Third Party Sales (on that site). Sorry.]

 

Link Referenced: Bob Atkins Site: Lens Testing. A guide to testing camera lenses

 

(On this lens you have to be far away - the MFD is about 20 feet!)