Converting RS-485 to RS-422 using optical extender with SDI Video transmission

Hello, I am currently using a Questtel SDI-over-fiber extender with RS-485 data for serial control. I have recently switched to a Canon CR-N300 camera, which provides an RS-422 interface for control. Given the differences between RS-485 (2-wire, half-duplex) and RS-422 (4-wire, full-duplex), I would like to confirm whether it is feasible to implement an RS-485 to RS-422 conversion within the signal path and maintain reliable communication over the existing fiber extender.
Specifically, can a protocol-transparent hardware converter be used in this scenario?
Any recommendations on compatible solutions for integrating RS-422 control over the current infrastructure would be greatly appreciated.

Buyer's Guide v1.0

I have been working on bringing back the Buyer's Guide and it has been quite the endevour. Version 1.0 will go live at some point in the coming days. Not all of the planned features will be implemented initially.

I don't have a team of testers, so we'll see how it goes once it gets traffic. I also want to get some feedback, there's no point in going down a path with features if it's the wrong path. I also can't think of everything end users would want to see.

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Canon Says it’s up to Sigma to Make Full-Frame RF Lenses

In a recent published interview with French publication Phototrend.fr, a pretty big bit of information came from Canon themselves. It doesn't sound like the lack of third-party autofocus lenses for the RF mount has anything to do with Canon. Full Frame Sigma RF Lenses While I touched on it in the interview, I think the […]

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Weird problem with 6D+100-400L II + 1.4x III=no AF

For some reason, only "MF" appears on my 6D top LCD, no AF activation on shutter. No attempt to focus. Tried mounting TC on lens, THEN on camera. Also tried mounting on BODY first, then lens. Still same. Same exact 100-400L II + 1.4x III transferred over to my EOS R and suddenly everything works perfectly. All switches in the proper position. Tried another lens on the 1.4x III + 6D and AF is working. So it's just the particular combo of the 100-400L II + 1.4x III + 6D where AF doesn't work. And yes I dismounted each individual piece and re-mounted until firm click multiple times. Any ideas? Cycled 6D on and off etc. The 100-400L II works perfectly on my Fuji bodies as well w/ and w/o the 1.4x III. Strange quirk with the 6D.

Cover Cap for removed tripod collar mount on 24-105 Z / 70-200 Z ?

Isn’t there any solution offering a cover cap for the mounting point when the tripod foot is removed on 24–105 Z or 70–200 Z? :unsure:

I was already quite surprised when I got my new 70–200 Z, back then I expected at least some kind of cap or alternative end piece to be included in the box. Something like the neat little short replacement foot you sometimes get with the white longer telephoto lenses.

Honestly, it’s a bit disappointing that no one at Canon seemed to put any thought into this. (n)

A few months later, when I also got the 24–105 Z, I thought: Alright, let’s check online, surely by now there must be some third-party manufacturers making something for this. Brands like JJC are usually pretty quick with accessories, and there are plenty of other chinese manufacturers as well. But to my surprise, I couldn’t find anything there either. :oops:

Of course, that doesn’t necessarily mean it doesn’t exist. I definitely don’t know every small manufacturer out there. And especially on social media and in forums, there are always clever people who design and produce niche solutions like this, whether via 3D printing or CNC machining in small batches, like those lens caps with AirTag slots, for example or hot shoe caps.

So, does this really not exist, or am I the only one bothered by this unfinished, sharp-edged mounting point? :unsure:

F00 conundrum

A camera body will show F00 and manual focus (MF) when it cannot communicate with a lens, which could be because there is no lens attached, because the lens is fully manual, or because there's a problem with the lens itself.

I went out birding over the weekend, mounted my usual combination of 600/4 II, 1.4xIII and the vanilla EF-EOS R Mount Adapter to my R1 and headed out. When I turned on the camera, it showed F00 and MF. I thought, "Oh, sh!t," and swapped on the 2xIII. That worked...but then it also changed to F00 and MF. So I mounted just the bare lens...and that was perfectly fine so I spent the day shooting like that.

When I got home, I cleaned all the contacts and tested various combinations again, including changing out the vanilla mount adapter for the drop-in version and my 3rd party adapter modified for an RF extender to fit behind it.

The upshot was this, and the situation is seemingly stable (through many trials over a couple of days, no changes). Happens on both the R1 and the R8, and with all three of the mount adapters.
  • Bare 600/4 II – functions normally
  • 600/4 II + 1.4xIII – F00 and MF
  • 600/4 II + 2xIII – varies between:
    • Normal function
    • Showing an aperture value that can be adjusted, but still only MF
    • F00 and MF
    • The variation is caused by physical manipulation – twisting the lens in the mount or moving the lens, e.g., lifting it from pointing down into shooting position, affects the functionality
  • 600/4 II + RF 1.4x (with Commlite adapter) – functions normally
The fact that I see this behavior with two bodies and three adapters suggests the problem is the TCs or the lens.

I haven't used the 2xIII TC quite some time, not since Comet C:2023 A3 Tsuchinshan-ATLAS in October 2024. So maybe the 2xIII failed sometime over the past 18 months (while sitting mostly undisturbed in a Pelican case with a dehumidifier unit), and the 1.4xIII failed sometime in the past 3.5 weeks since I last used it.

If it's the lens and not the TCs, the problem is specific to use with EF TCs and yet the problem exhibits different symptoms with the two TCs, and I don't know why that would be the case. Admittedly, I would prefer it to not be the lens, because the service life for the 600/4 II ended last year, so sending it to Canon is not an option. I could replace it with the RF 600/4, but I suspect we'll see a version of that lens with the 1.4x TC and hopefully fairly soon. I would love to have the latter and would not love buying twice.

One other idea occurred to me, literally as I was typing this post. I started to write that I don't have any other TC-compatible EF lenses with which to test the extenders...and realized that while that is true, I do have three other EF mount lenses that are physically compatible with the extenders, but don't report them to the camera body (TS-E 17, TS-E 24 and MP-E 65). So I tried the 1.4xIII and the 2xIII with the TS-E 24, and I found that the 1.4xIII shows F00, and the 2xIII shows an aperture value that can be adjusted.

It seems rather unlikely that both TCs independently failed, but I am thinking that's exactly what has happened. Sort of a Sherlock Holmes, "When you have eliminated the impossible, whatever remains, however improbable, must be the truth," sort of thing.

From a practical standpoint, assuming that I'm correct and both extenders have failed, I see no need to replace the 2xIII. One option would be to replace the 1.4xIII ($480 new or $280 used), but I can also just use the RF 1.4x behind my modified Commlite mount adapter, and just remember that I'm doing that since it's not reported in the EXIF. The downside to the latter is that I would not benefit from the DxO lens profile for the combo (though I could batch edit the EXIF and I suspect that DxO would use the 600 II + EF 1.4xIII profile, it still won't be the right profile).

Thoughts, suggestions, and sharing prior experience welcome!

Edit: the RF 1.4x itself does show up in the EXIF, but the exposure information doesn't reflect it, remaining 600mm f/4.
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Sony Suspending Orders of Memory Cards Due to Shortages

We all know about the current market conditions for various storage solutions. The AI datacenter demand that won't subside for years has already taken Micron out of the consumer market, and now Sony is suspending sales of their CFexpress Type A, Type B and SDXC/SDHC memory cards. Statement from Sony (Translated) Due to the global […]

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Canon Will Continue to Expand the RF Lens Lineup at 6 to 8 Lenses a Year

French publication phototrend had their annual interview with Canon executives at CP+ 2026 and came away with some good information about the current EOS R lineup and their future plans, but in true Canon fashion, they didn't let too much out of the bag. The Canon EOS R6 Mark III The Canon EOS R6 Mark […]

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canon r7 keep or sell...

Hi I am new here, but need some advice! I have a r5m11 and also a r7. I bought the r7 for bird photography and the crop sensor. I haven't used the r7 really at all.....
So I am trying not to become a hoarder but then something inside me says keep the r7 but the other side is technological obsolescence and the new r711 coming out soon.
I have an offer from an online platform to buy the camera for 800 which is 1/2 of what I paid and again, the camera has been used maybe 4 x. so trepidation in selling at such a discount. I also have the rf 100 macro lens (used rarely) - they are offering me 1/2 price on that as well. What would you do. I don't want to be stuck with an obsolete camera but I don't really want to sell at 800 that seems way off the mark. thank you Bianca

R5 Mark II vs BMPCC 6K G2 - dynamic range, aspect ratios etc

I've got the R5 for a few months now, and have been loving it despite a few shortcomings. In my first review I compared it with my previous body, the 5D Mark III, just to have a crystal clear vision of the differences. I decided to keep the 5D, since two bodies are always useful, but I also had another piece of equipment to compare it with: a proper video camera. I had bought the 6K G2 from Blackmagic to have better low light performances when shooting video than with the 5D. I had some video project in mind, but still didn't use it much. While I am still interested in video, I don't like to keep things on a shelf if i don't use them, and now that I have an R5, which promises great video stuff, I wanted to compare the two and make a final choice about keeping or not the 6K G2.

Disclaimer: this review is very partial. I focus only on the things that I care about, which are still significant in my opinion since I could not find a similar review on youtube or google. I didn't do proper recovery tests, didn't pixel peep, didn't match the framing perfectly etc etc I am dividing this review in sections I care about.

- Settings and gear
I was interested in comparing RAW videos only. On the R52 I did 4K sRAW and 8K cRAW. On the 6KG2 I did 1/8 and 1/3 compression. This gives roughly similar bitrates. On the R52 I was using the EF 28mm opened at f8, 800 ISO. On the 6KG2 the Sigma 18-35 at 18mm f5.6 400 ISO. Which gives me the same DOF, same exposure. On both I had a breakthrough ND filter X3, slightly higher model for the R52, but I doubt that it matters. On interiors I switched to 4000 ISO vs 3200 ISO and tried to match the exposure. For sound, on top of the R52, I used a Sennheiser MKE 440. On the 6KG2, the AT 875R.

- Color
This is probably one of the most important aspect of the comparison. The core of any quality discussion. I graded both the images in Resolve, which gives a significant edge to the 6KG2 since Blackmagic does both the software and hardware in this case. The 6KG2 files are flawlessly interpreted. You just set the white balance, add the contrast that you desire, and you are all set. I didn't even touch nodes for it. On the R52 side, things are completely different. I had to work a bit to try to match the images. It's not too bad, but it is definetely work. Also a very different look to start with that what you get on the R52 camera itself. Eventually the images do match, except for the clothes which can look different. I could have spent more time to make them 99% equal, but I didn't bother. I am also sure that there are tons of LUTs available for the R52, but I prefer to grade myself. So, the 6KG2 is definetely preferable as a workflow if you are inside Davinci, but since you have RAW files with Canon you can do whatever you want with them.

- Dynamic range
That's another crucial element. My biggest complaint in the previous R52 review. As you can clearly see in the comparison screenshots the 6KG2 has two extra stops of dynamic range in the highlights. The R52 completely looses any detail. There is nothing to recover. This is unacceptable from a camera that costs almost double, and I wish that reviewers would start to point this out more often and stop saying that "all cameras are so good nowadays". They are not. The top of the line hybrid Canon still has horrid dynamic range that cannot keep in a normal sunshine day. If Blackmagic can do it, why Canon cannot? What also bothers me is that if you don't use the base ISO on the R52 the image completely implodes, in a way that I do not think happens on the 6KG2. I didn't test this properly, I had just tried to use ISO 100 on the Canon and was so disgusted that I let it go entirely. Again, issues with dynamic range.

- Noise and sharpness
On properly exposed base ISO low videos, I could not notice much noise in either camera. Moving on to base ISO high, the 6K is clearly cleaner, but there could be baked noise reduction going on, so it feels unfair to judge the Canon for this. The files clean up well in Resolve, and there is enough detail, so I don't think I care that much. Speaking of sharpness more broadly, I feel like both cameras do great and increase in detail when you increase resolution or decrease compression. I really didn't want to spend time to pixel peep the difference though. 4K sRAW on the R52 is enough for me. I also think that a softer image benefits narrative videos.

- Size
You gotta love how compact an hybrid camera is. I am also to blame, since I have fully rigged the 6KG2, so in comparison it is quite bulky while the Canon is so light, and I can feel like I can go around all day with it strapped on my neck. I guess that a 6K full frame would be better for a small profile for a variety of reasons: l mount being tighter, full tracking autofocus means you don't need a follow focus, brighter screen means you don't need a sun-hood, cfexpress means no external SSD. It all piles up. For me this is a deciding factor, since I want to go around by myself, but conversely a bigger profile looks more "professional" for a lot of people. So it all depends on your usage.

- Focus
The 6K2 doesn't have tracking. You can pick a spot and it will focus there, but that's it. The R52 has tracking and a good one. But the whole mechanic is super weird unless I've missed something. If AF servo is on it will keep the focus on your subject, but if that gets out of the screen it will try to focus on something else, and it will not come back to that subject if it comes back on screen. Looking at some videos on youtube, it looks like the 6KFF has a way smarter autofocus that you can actually set up to come back to the thing you pointed it out to, or a specific spot. But that's another camera. In this comparison the R52 is clearly easier to use if you are just shooting videos by yourself and are not in a controlled environment. Tracking autofocus is a must to actually focus on what you are shooting instead of having to squint at a screen.

continues...

Canon, please make this: RF 35mm pancake with weather sealing!

Hi all,

I’m a big fan of the RF 28mm f/2.8 pancake, and I ordered it as soon as it was (surprisingly) announced. To me, it signalled a refreshing new direction for Canon’s RF lineup.

While it has one of two minor shortcomings — that is the lack of weather sealing and somewhat imperfect flare control — it excels in so many areas (image quality, autofocus speed, size, and weight) that I often struggle to justify taking any of my RF L lenses out for street work. Even lenses like the RF 35mm f/1.4 VCM tend to stay at home when this remarkably capable little pancake is in my bag.

I’m curious to hear what others think: do you share a similar appreciation for this lens? And would you be interested in a comparable 35mm pancake — ideally with weather sealing?

Cheers,
Farhang

SanDisk Sounds the Alarm About Near Future Storage Price Hikes & Supply

If you're in our industry, you already know that storage prices are going through the roof due to AI datacenter needs. Not only storage, but RAM, DRAM Flash Memory and a lot more in the industry will see significant price increases through 2026. SanDisk is now sounding the alarm about what's coming as far as […]

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New DxO PhotoLab 9.6 Delivers Upgraded Image Quality with DeepPRIME XD3

The latest update extends DeepPRIME XD3 — now for both Bayer and X-Trans sensors — adds diffusion to its acclaimed AI Masks, and introduces High-Fidelity Compression to create DNG files up to four times smaller. DxO, an imaging leader has launched their new version of PhotoLab. With version 9.6, DxO brings us DeepPRIME XD3, which […]

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