topic Re: RF100-500 soft at 500. did I get a bad one? in EF & RF Lenses

RF100-500 soft at 500. did I get a bad one?

doug86 — Mon, 18 Mar 2024 12:47:49 GMT

I Purchased a new RF100-500mm last month, and took it out in the field for a month. But out of the box, it wasn't producing sharp images with my R6 body. When shooting some birds in flight, I was next to a friend who had the same lens on his R3, so we swapped lenses and did a test. He shot both his lens, then mine, shooting in manual so the settings remained the same. Same light, same bird about one minute apart.

Here are the two, side by side. The one on the left is my lens (which I think is soft) and the picture on the right is his lens. What do you think? (Zoomed in with Lightroom)

Re: RF100-500 soft at 500. did I get a bad one?

ebiggs1 — Mon, 18 Mar 2024 15:17:42 GMT

Got to say this so just hold on, but almost all OOF or soft images are user caused and not camera or lens issues. Now that is not to say there can't be a camera/les problem but keep in mind the chances are small.

However you can't use the samples you displayed as proof. You need to set up a real static test where everything is essentially exactly the same. A good tripod and a good test subject are best. Exact settings and camera. You know all the same. Same, same completely. So, don't discount your lens yet.

Re: RF100-500 soft at 500. did I get a bad one?

doug86 — Mon, 18 Mar 2024 16:31:21 GMT

@ebiggs1 wrote:
Got to say this so just hold on, but almost all OOF or soft images are user caused and not camera or lens issues. Now that is not to say there can't be a camera/les problem but keep in mind the chances are small.
However you can't use the samples you displayed as proof. You need to set up a real static test where everything is essentially exactly the same. A good tripod and a good test subject are best. Exact settings and camera. You know all the same. Same, same completely. So, don't discount your lens yet.

sure, that I understand. the problem is, I don't have 2 identical lenses, so this was simply an opportunity to do some testing. I understand that is is usually settings and user caused, but I have 30 years shooting canon lenses and bodies, and I feel that I have a realistic expectation of their capabilities. This particular lens was new, but I'm pretty sure its a grey market lens (from Abe's of Maine), as they are not an authorized Canon dealer.

The question remains: do you think those two photos show equal sharpness? The settings are clearly shown in my post.

Re: RF100-500 soft at 500. did I get a bad one?

March411 — Mon, 18 Mar 2024 17:33:34 GMT

You can still achieve your goal with your lens by controlling the environment.

Set up the camera on a tripod with good lighting, outside will be fine if you have good skies.
Place an item with some detail on a surface, a statue, animal figurine, toy or something with text. I use a shovel handle with a textured grip that has screws and a logo on it. B&H or Amazon has Back focus Chart and White Cards that work well if you want to drop a couple bucks.
Setup at a max distance where the item fills a good portion of your viewfinder and take some test images.
Use a remote or two second timer to take the picture, it will give you more clues to the real issue. You may be moving when you shutter the lens. Eliminate potential challenges and variables with hard controls.

This will give you a good indication on how to evaluate if it's you or possibly an issue with the equipment.

Re: RF100-500 soft at 500. did I get a bad one?

jrhoffman75 — Mon, 18 Mar 2024 17:35:05 GMT

Assuming all the post processing settings were the same I would agree that the image of the bird on the left is not acceptably sharp.

But, it looks like the water on the left is sharper than the water on the right, so perhaps there is a focus issue? Was one camera AI Servo and the other One Shot AF? Can you post a link to the RAW files?

Re: RF100-500 soft at 500. did I get a bad one?

doug86 — Mon, 18 Mar 2024 17:45:35 GMT

both photos are with the same camera, swapping lenses. The shutter speed is 1/5000 on both, so camera shake would be eliminated in that case, even with NO IS in play. I'll try to post the raw somewhere.

Re: RF100-500 soft at 500. did I get a bad one?

March411 — Mon, 18 Mar 2024 19:26:56 GMT

I would agree with John, the one on the left the water is sharper and the one on the right it appears that the eye/head is sharper.

That was my rational for trying some controlled exposures with the tripod.

Re: RF100-500 soft at 500. did I get a bad one?

doug86 — Mon, 18 Mar 2024 19:35:24 GMT

https://photos.app.goo.gl/73b6nB3LqL2SjCJE6

first photo was with the suspect lens (my lens), other photo is with my friends lens. Both shot on HIS R3, with same settings. I think the background difference is due to the bird's distance from the waves. The photos were taken about one minute apart.

Re: RF100-500 soft at 500. did I get a bad one?

jrhoffman75 — Mon, 18 Mar 2024 20:09:22 GMT

It looks like the files are converted to small JPEGs when downloaded. Can you use Dropbox?

Re: RF100-500 soft at 500. did I get a bad one?

wq9nsc — Mon, 18 Mar 2024 20:12:56 GMT

I also agree with John that there isn't a clear sharpness difference but instead where the critical focus occurred. This was a BIF so you have the focus system predicting movement and predictions aren't perfect. It would be no difference than shooting a fast series where some of the images from the sequence are near perfect while others are less so.

Both appear to be cropped so severely that they are into the "pixel peeping" mode such that neither has acceptable image quality at that level of cropping.

Rodger

Re: RF100-500 soft at 500. did I get a bad one?

March411 — Mon, 18 Mar 2024 21:28:40 GMT

I believe Rodger has made a valid point after reviewing the images and believe that the challenges would remain the same regardless of RAW vs JPEG.

The results of the two different images could be a result of the focusing system being more accurate when you took the image using your friends lens. I believe that the second point Rodger made is more valid, the subject is less that 20% of of the full image. This will in most cases create softness. Several things can impact long range images and smaller in frame subjects such as atmospheric conditions (atmospheric haze), thin depth of field, vibration or movement is more impactful at greater distances and chromatic aberrations.

Bench test your lens and find out.

Re: RF100-500 soft at 500. did I get a bad one?

wq9nsc — Mon, 18 Mar 2024 22:14:39 GMT

Severe cropping becomes more of an issue as ISO is increased.

The attached is cropped from 17% of the sensor area of my 1DX III but conditions allowed for the capture to occur at ISO 320 with an EF 800 f5.6 @ 1/1250 f8 thus making severe cropping more viable. The second photo has about the same crop percentage (18%) but was captured at ISO 100 using a 1DX III with a EF 200-400 f4 extender lens @ 1/1600. The final shot is also a 17% crop with a 1DX III using an EF 800 f5.6 plus a 1.4X @ 1/1600 and ISO 500.

I suspect that the bird captures in the original post could have been captured at a slower shutter speed resulting in lower ISO and higher IQ given the cropping.

Rodger

Re: RF100-500 soft at 500. did I get a bad one?

Waddizzle — Mon, 18 Mar 2024 23:57:52 GMT

“ Here are the two, side by side. The one on the left is my lens (which I think is soft) and the picture on the right is his lens. What do you think? (Zoomed in with Lightroom) “

You are zoomed in to over 250%. Where is your locked AF point? You can use the Canon DPP4 to view where your locked AF is located, too.

A “one-off” shot like this is inconclusive, IMHO. You are making the assumption that you should have a 100% keeper rate.

I also suggest that you perform more controlled testing. You do not need a second lens or a different camera, either. Use your own gear, seeing how that is what you would be using.

Re: RF100-500 soft at 500. did I get a bad one?

ebiggs1 — Tue, 19 Mar 2024 14:25:52 GMT

"A “one-off” shot like this is inconclusive, IMHO. ... I also suggest that you perform more controlled testing."

No matter what troubleshooting guesses others have made or will make it is useless if you do not heed that advice and mine from above. You simply can not make a meaningful judgement from what your examples show from how you captured them.

This...

"I also suggest that you perform more controlled testing."