RF 24-70 2.8 vs RF 24-105 F4

[BobU]

I have both I seriously believe I get better images with the 24-105. Crisper. Less noise or less apparent noise at high ISO. I never have to think about the quality. my best say "wow, that's a good shot". While with the 24-70 I sometimes have to think about it.

I had thought might be shutter speed so set to 200 so that should elimniate that issue at any focal lenght. Not it. I do not think it contrast, but could be. Lightroom adjustments do not compensate for what I see and have trouble describing.

Cannot send to Canon and say I don't think its working as well as my 24-105 What would you do? Don't get me wrong, its not bad and better than the 24-240 I recently tried. But it is just not as good.

Here's a recent 24-105 and a recent 24-70. Not the same place or time, but a quickly grabbed example. Might show what I am trying to describe.

Anyway, appreciate thoughts.

 

[RedCobra]

If we are comparing the RF 24-105 f/2.8 L IS Z to the 24-105 f/4 L (not the 24-70). I sold both the F/4 and the f/2.8 24-70 and bought the 24-105 f/2.8.
Sharp.
Long (had to get a new bag)
Heavy (same weight as the RF 100-500)
Did I say Sharp? to me it is sharper than both the F/4 and the 24-70 f/2.8

 

[BobU]

No no no no no.

RF 24-105 F4 and RF 24-70 F2.8

 

[RedCobra]

No no no no no.

RF 24-105 F4 and RF 24-70 F2.8

Sorry, read the header wrong.

 

[BobU]

Just sent the 24-70 in for calibration. Will see if that helps. I hope so.

 

[BobU]

Lens back. The large piece of something inside the lens gone, but still a little dust. Nothing much, but....

They did not says what or even if they calibrated the lens. They say next to nothing in their work summary. BUT, it is MUCH sharper and more contrasty. As I would have expected all along.

Unfortunately, something new in the lens. Unnaceptable to miss this. Looks like aluminum though the pic does not show that clearly. It does shine. It is not in the image path most likely. But bothers the hell out of me and I would think might affect resale value. So torn as to whether to send it back for this to be removed and even risk the image quality I gained to be lost. Yet hard to know its there

What would you do? Its right by the "82" in the image.

 

[BobU]

I sent it back in...

 

[BobU]

Long story not so short.

I sent it back. They removed the object. Never said what it was, where it came from or why they missed it after cleaning the other object. Or if I should be concerned about more, maybe even near the helicoils. But the box was crushed.

It was not as sharp as when it came back the last time. And, you might recall, I still thought my RF 24-105 F4.0 Much crisper and taking better images. Same with RF 70-200 F2.8. So never happy with this lens and less so now.

Talked Canon into yet another call tag but they wanted JPGs. And truth be told, the rep could not see what I was seeing. Or not seeing. But it went in with a 6 page letter . Service replied "lens damaged, does not focus". But if there was damage not visible and it did focus, just not up to its reputation.

Well, it came back today. It is finally what I expected it to be. Might even be my new favorite lens!

I wrote to Canon as to why they could not do this the first time? And why they will neither tell me what was wrong or what they fixed. Why the mystery. And how did they miss the "new object" inside the lens after they removed another?

Reminded them this was the time of 3 techs and they paid 5 of the 6 legs of shipping. How much happier we all would have been if they did this the first time. And how much more confidence I would have in the service.

But, I also learned to trust myself. If I feel a piece of gear is under performing. I am usually right.

 

[BobU]

A few more. My test spot. Very quick shoot today.

 

[Archibald]

Bob, you are basically talking to yourself in this thread. From what you posted, I can't see the problem, and have no idea whether you were hallucinating or not. That's OK, though, you don't need to convince us. You just needed to get satisfaction. For now, you appear to have that.

I once had a problem with a Canon lens. The AF was inconsistent at greater distances. Sent it in under warranty. They did some stuff to it but it didn't change anything. Sent it in again, and again no change. Gave up and worked around the problem. Then a few years later I got a new better body, and figured maybe NOW that lens will perform. And it didn't. Sent it in, this time to Canon US, and at my own expense. After 3 more iterations of this, with them changing parts that were not relevant to the complaint and no improvement, tensions were getting high.

Then I got a phone call from a Canon tech. He acknowledged the issue (first time they did that) and then explained that it was normal behavior for that lens. He called it a "feature". Ha ha. What a feature. From what he told me and my own observations, I deduced that the mechanism moving the AF module inside the lens was not precise enough and often landed a bit off the goal. Not always, but often.

So that problem was unfixable.

One of my happiest days was selling that lens. The buyer never complained. Anyway, the lens was performing to spec.

I've had other problems too, and it can get very confusing. Sometimes you don't really know if it is a problem or not. Is it sharp? Kind of... but it should be sharper! Am I expecting too much? I had that problem lens on a body that also had an issue. It takes hours of testing to find out what is going on.

My RF days have been much better. Phew. Very few problems.

 

[BobU]

I might be talking to myself, Archibald. You're right. But then someone might find this thread on a search and it could be helpful.

Its near impossible to see the subtle details in 1200 dpi images after uploading to who knows what engine to convert nd display. But the differences ARE there. Ask most people, the 24-105 shpould not be significantly sharper wide open (even though a stop difference) then the 24-70. And it was. 100% crops clearly showed this. And the 70-200 much sharper as well wide open. Mine was off and it took the THIRD tech to agree and align the internal lenses properly.

I was going to sell this lens as well. But now one of my favorites and may replace the 24-105 in my go to bag. Trust yourslef if you think a lens is underprerformaning. And be persistant.

 

[DaveTX]

If you are chasing a problem such as what is described in this thread simplify your experiments and control the conditions. Get a resolution chart and shoot images of it under the same lighting, shutter speed, aperture, focal lengths, distances, and processing. Use a tripod to help keep things fair, too. Then compare the images with an eye towards lines per millimeter numbers and contrast. You will get solid answers much faster than by eyeballing images of different scenes taken under radically different lighting conditions. Edmund Optics is a good source of resolution charts. There are charts that you can download an print that might help you with an answer if you have a good printer.

I bought this chart when I was initially climbing the R5 learning curve and it helped me with some lens and extender choices. https://www.edmundoptics.com/f/resolving-power-chart/11903/
I mounted it on foam board so that it is flat and easy to hang vertically.

 

[BobU]

That's a great tool. However, in my case, it was obvious to me there was a difference and the 24-70 not performing as expected. Took three tries at Canon, for them to "get it" but now one of my favorite lenses. The tool would likely only frustrated me more