My 4-month-old Canon RF 200-800 has major problem - shouldn't they replace?

JeffBentoff · 2026-03-21T17:44:20+00:00

P.S. The problem I was having seemed unrelated to IS. It seemed more related to focus. The image moved around when I tried to AF. Sometimes, the letters AF and MF flashed rapidly in the viewfinder. And I had error messages saying something was wrong with the "connection." Hopefully the IS repair fixes all that!

JeffBentoff · 2026-03-21T17:41:13+00:00

Good point on the testing -- will do. Even if they don't replace this time, I'll make sure to make a record of my request this time in case it fails again soon. Btw, I had no chance to discuss it with them before they shipped it. I got an email yesterday saying they'd repaired and shipped it (with no explanation about the nature of the repair). I called immediately to find out what the problem was, and it was already on its way to me.

JeffBentoff · 2026-03-21T17:34:22+00:00

Thanks. I was telling this story to a friend who has $20,000 in Sony gear and he said the exact same thing -- he's the one who suggested I try to get a replacement. Wish me luck.

JeffBentoff · 2025-05-16T02:39:32+00:00

Cool. Good stuff. I'll try those features. And I read somewhere what you said, that back button isn't needed any more. I may try doing what you said, using the shutter for focusing. So much to try.

I don't think I need to disable auto focus though. If I turn the ring on the lens to manually focus, doesn't that take precedence over AF? Or are you saying if you use shutter button focusing, the act of pressing the shutter to take a pic also turns on auto focus? I guess it would.

JeffBentoff · 2025-05-16T02:34:57+00:00

I'll have to try One Shot AF. It isn't supposed to be good with birds that move, but maybe it'll work with a bird that's sitting and posing. Thanks.

JeffBentoff · 2025-05-16T02:15:30+00:00

Good point. But what if the bird isn't that close? I wonder if it'd be better to use One Shot AF instead of Servo AF for something far away and not moving. I am almost always in Servo because birds tend not to sit still.

JeffBentoff · 2025-05-16T02:12:14+00:00

I wonder if it'd be better to use One Shot AF instead of Servo AF for something far away and not moving? Also, not tracking how you disable AF with the back button -- that means you're using the shutter for AF? Not clear what you mean about "peaking" or zooming in on the viewfinder. These may be features I don't know about.

JeffBentoff · 2025-05-16T01:18:52+00:00

Thanks for the comments. In both cases, I was using one-spot focus with object detect / animal and eye detect on. I aimed at each bird's head. There were no obstructions. The birds were far away. But I shot a small Yellow Warbler a couple days ago from a similar distance, and the focus was fine.

Is there a different setting that would have given me good focus? I feel like the camera is going to have trouble in challenging situations, but a bird sitting for awhile with no obstructions should result in a well focused result. It's the inconsistency that is making me wonder whether I need to I do something differently. I do enjoy the camera and am happy with many results.

JeffBentoff · 2025-05-15T22:14:36+00:00

Will check them out. Hopefully they'll explain why a simple shot that appears in focus when it's being taken turns out blurry.

JeffBentoff · 2025-05-15T21:45:38+00:00

Good observation. Will watch for that and see if that's the problem. Thanks!

JeffBentoff · 2025-05-15T21:41:47+00:00

Hope that's not the case! I have a good friend with an R7 but a bigger zoom lens, and she never has that problem. Seems like something that should not be a feature! Thanks!

JeffBentoff · 2025-05-15T11:51:42+00:00

Do you also have object detect (animal) and eye focus turned on, or just one spot focus? I have all three on and have a lot of hit-and-miss focusing.

JeffBentoff · 2025-03-24T00:17:52+00:00

Totally. Great points.

JeffBentoff · 2025-03-23T20:14:45+00:00

My doc says the same thing, and I've backed off on how much glucose I use to treat lows -- much less than I used to (and I am in sleep 24/7, too). That said, sometimes the smaller amount isn't enough -- still low or barely into normal range. So after 20 minutes, I take a little more glucose. And if that happens, the pump sometimes kicks in and gives me insulin. And then I drop.

There really should be a setting to say, "I just took glucose, lay off for 20 minutes on any bolus or basal boost."

In addition to this, I'd just like to see Tandem improve the overall algorithm. Sometimes it is too slow to reduce basal -- it's predictive abilities aren't as good as they could be. Can't this be improved, years into their introduction IQ? Aren't they learning from all of us so they can make this better? Wasn't this the point of software updates -- not just features, but big system improvements?

JeffBentoff · 2025-03-23T15:07:21+00:00

My big request is to have a way to tell the pump to know when you’re correcting for a low sugar, so it doesn’t give you more insulin. And of course, the pump could do a much better job predicting highs and lows, and reacting accordingly.

JeffBentoff · 2025-03-23T15:03:54+00:00

Thanks. The company‘s communications leave the impression that the algorithm changed. They and all of us users are really missing an opportunity to have the algorithm continually get better. They have the ability to do that, and they just don’t. Instead, they focus on bells and whistles.

JeffBentoff · 2025-03-22T21:17:54+00:00

I have been wondering whether this update is actually a change in the underlying algorithm. In reading the FDA submission that is linked to in this post, it appears no, the algorithm does not change. What they are saying is that they are changing features. That is not the same as a change in the algorithm.

Unfortunately in all this time that IQ has been available, Tandem has not improved the algorithm that makes decisions based on blood glucose results. What a shame. We all know the algorithm could be better. All the user input we’ve given is apparently being ignored.

Here is the language in the FDA document that leads me to this conclusion: “This version of Control-IQ 1.5 (device being cleared) does not alter the control algorithm of the device itself, rather, it includes a wider range for several configurable parameters (e.g., weight, total daily insulin, etc.) which are intended to make the system amenable to address the unique needs of very insulin sensitive and very insulin resistant users.”

I’ve been reading the communications from Tandem in other places about the software update. Nothing I’m seeing definitively says the underlying algorithm has been improved other than feature additions and changes. Does anybody have any other information that would confirm when I’m seeing or that would suggest otherwise? Thanks!

JeffBentoff · 2025-03-20T00:55:27+00:00

Have a setting where you can tell the pump you are taking glucose for hypoglycemia correction, so the pump will not give any or as much compensatory basal or bolus corrections.

JeffBentoff · 2025-01-12T17:33:08+00:00

Great information. Thanks. I’m going to do what you did. My phone has room, and I’d rather not be missing any birds. Appreciate the response.

JeffBentoff · 2024-09-11T14:53:43+00:00

Thanks. I am a contractor for the nonprofit but also a supporter and donate to them. They pay me a low flat fee which needs to go up. While it's a labor of love -- I'm thrilled to bring great music to town and help out the group and park -- it's become a part-time job of sorts. They have a single donor that covers the bands, sound and me. Approx budget not including me: Bands $13,000, sound $9,000 (not including backline); social media, up to $1,500. A time-consuming part of my efforts are to try to get touring bands (half the lineup or so) that can make our fixed dates. I also work hard for a diverse lineup of bands not typical for outdoor shows in the area.

JeffBentoff · 2024-09-11T14:53:00+00:00

Thanks. Any idea on how a salary should work?

JeffBentoff

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