Manual Focus on SX620HS not working

LeTomas

Manual Focus on SX620HS not working

« on: 17 / September / 2021, 21:16:17 »

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Hello, so I got CHDK today because I wanted to gain access to focusing manually, but ironically it's the only thing that doesn't seem to work, I've seen videos of people using it on other models and I can tell it doesn't work for me because when I change the subject distance (displayed as SD) I can't hear the servo moving neither see the focus changing when moving the zoom dial thingy, also when trying to take a photo with CHDK manual focus turned on, the camera still focuses automatically.
Is there any solution for this?

I launched the script MFTEST.LUA but the camera crashed.
I also tried installing build 100c alpha (As someone did here https://chdk.setepontos.com/index.php?topic=13426.msg144517#msg144517), but my camera wouldn't even turn on with it installed, STICK always installs 100b when I analyze a photo taken with it.

Also, this model (SX620HS) doesn't feature a DISP. button which is required for some CHDK inputs including setting focus to Infinity, does anyone know if some other button acts as DISP. on this model? There's a wi-fi button where normally that DISP. one would be on most models (bottom left), but doesn't do anything.

IMG_20210917_215601.png (58.1 kB, 168x168 - viewed 3 times.)

« Last Edit: 20 / September / 2021, 13:28:02 by LeTomas »

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reyalp

13386

Re: Manual Focus on SX620HS not working

« Reply #1 on: 17 / September / 2021, 23:41:09 »

Quote from: LeTomas on 17 / September / 2021, 21:16:17

I also tried installing build 100c alpha (As someone did here https://chdk.setepontos.com/index.php?topic=13426.msg144517#msg144517), but my camera wouldn't even turn on with it installed, STICK always installs 100b when I analyze a photo taken with it.

The version (like 100b) needs to match the Canon firmware version of your camera, so this is correct, expected behavior, assuming your camera is 100b.

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I launched the script MFTEST.LUA but the camera crashed.

This is also expected, if you had all tests enabled and "Bypass interlocks" checked.

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I've seen videos of people using it on other models and I can tell it doesn't work for me because when I change the subject distance (displayed as SD) I can't hear the servo moving neither see the focus changing when moving the zoom dial thingy, also when trying to take a photo with CHDK manual focus turned on, the camera still focuses automatically.
Is there any solution for this?

From previous reports CHDK is only able to override focus in MF or AF Lock mode. However, neither of these are available in the canon UI, so you will need to use script to activate one before using SD override (see this discussion in the porting thread https://chdk.setepontos.com/index.php?topic=13426.msg143890#msg143890)

Short version: If you select setfmode.lua from the script directory and run it, you should be able to use SD override after that. If you change canon shooting modes, or switch to playback, it will probably need to be re-run. You can also use the script to switch back to AF.

Unfortunately, none of this is very convenient for real world shooting.

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Also, this model (SX620HS) doesn't feature a DISP. button which is required for some CHDK inputs including setting focus to Infinity, does anyone know if some other button acts as DISP. on this model? There's a wi-fi button where normally that DISP. one would be on most models (bottom left), but doesn't do anything.

The wifi button doesn't appear to be used for normal CHDK shortcuts on this can. It can only be assigned as the alt key.

It looks like UP should the SD override toggle on this cam, and "infinity" will have no usable key assigned.

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LeTomas

Re: Manual Focus on SX620HS not working

« Reply #2 on: 18 / September / 2021, 03:09:36 »

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The version (like 100b) needs to match the Canon firmware version of your camera, so this is correct, expected behavior, assuming your camera is 100b.

Oh okay so I should only stick (pun intended) to 100b then, good.

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Short version: If you select setfmode.lua from the script directory and run it, you should be able to use SD override after that. If you change canon shooting modes, or switch to playback, it will probably need to be re-run. You can also use the script to switch back to AF.

Okay, so I just tried doing that and yeah, now AF is disabled, but still can't seem to do SD overdrive, though it's not the end of the world for me because I'm using this camera primarily to scan film negatives so I'm thinking that I can just let the AF focus close enough on the film, lock it and then move the camera up or down to manually do fine adjustments by taking advantage of the now locked Focus.
Thanks a lot for this! Do you have any clue why this is happening? Hope there's an update sometime to fix this, but for now this is way better than relying on the camera's AF, so again, thanks

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The wifi button doesn't appear to be used for normal CHDK shortcuts on this can. It can only be assigned as the alt key. It looks like UP should the SD override toggle on this cam, and "infinity" will have no usable key assigned.

You mean that this wifi key could be remapped to DISP. or something like that?

« Last Edit: 18 / September / 2021, 13:58:43 by LeTomas »

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reyalp

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Re: Manual Focus on SX620HS not working

« Reply #3 on: 18 / September / 2021, 15:26:59 »

Quote from: LeTomas on 18 / September / 2021, 03:09:36

Thanks a lot for this! Do you have any clue why this is happening? Hope there's an update sometime to fix this, but for now this is way better than relying on the camera's AF, so again, thanks

What shooting mode you have the camera in? I'd suggest using P (M, Av or Tv are also fine on cameras that support them, but AFAIK sx620 does not) Some settings mentioned below may not be available in other modes.

In the Canon menu, is are settings like "Serve AF" or "Continuous AF" enabled? If either are on, turn them off. I would also set "AF frame" to "Center", rather than any of the face detect or tracking options.

Another possibility is that the CHDK SD override UI is confusing. When SD override is activated and you are in alt mode, you should see (probably red) text in the upper left that says
SD : <number>
Adj: <something>

Adj is the amount that the zoom lever will change focus distance. If it's "off" then you need to press the right button on the dpad to set the increment before the zoom lever will have any effect.

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I'm using this camera primarily to scan film negatives

FWIW, you might find the PTP extension (https://chdk.fandom.com/wiki/PTP_Extension) useful for this kind of project. You can view the camera live view, control settings and shoot using the chdkptp application (https://app.assembla.com/spaces/chdkptp/wiki).

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You mean that this wifi key could be remapped to DISP. or something like that?

I was only describing how it's currently configured in the port.

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LeTomas

Re: Manual Focus on SX620HS not working

« Reply #4 on: 19 / September / 2021, 17:55:56 »

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What shooting mode you have the camera in? I'd suggest using P ... are settings like "Serve AF" or "Continuous AF" enabled? If either are on, turn them off. I would also set "AF frame" to "Center"

Yes, all of this I've already been doing (P mode and AF stuff turned off), I only have this focus zoom center frame thing turned on.

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Another possibility is that the CHDK SD override UI is confusing. When SD override is activated and you are in alt mode, you should see (probably red) text in the upper left that says
SD : <number>
Adj: <something>

When attempting to do manual focus I'm changing both SD and Adj values with their respective keys and nothing happens, though something weird happens when the value is close to 0 and I hold the Zoom dial to the left as if i were decreasing SD with a i.e +100 Adj value and not singular units, it sort of goes to either infinity or the closest possible focusing distance (can't tell which one of both) as long as I hold the dial to the left, then it goes back to the last SD it had when it last auto-focused, I see no application in this but it's kind of a quirk since I can't really take a shot while holding it down.

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FWIW, you might find the PTP extension useful for this kind of project. You can view the camera live view, control settings and shoot using the chdkptp application

Oh wow, this has a lot of potential in speeding up my workflow on what I'm using this camera for, I'll try it out, who knows, I even might be able to control SD via it. Thanks a lot!

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reyalp

13386

Re: Manual Focus on SX620HS not working

« Reply #5 on: 19 / September / 2021, 18:39:07 »

Quote from: LeTomas on 19 / September / 2021, 17:55:56

When attempting to do manual focus I'm changing both SD and Adj values with their respective keys and nothing happens, though something weird happens when the value is close to 0 and I hold the Zoom dial to the left as if i were decreasing SD with a i.e +100 Adj value and not singular units, it sort of goes to either infinity or the closest possible focusing distance (can't tell which one of both) as long as I hold the dial to the left, then it goes back to the last SD it had when it last auto-focused, I see no application in this but it's kind of a quirk since I can't really take a shot while holding it down.

If you have Adj set to say, 100, and click the zoom, what happens? Does the displayed SD value change, or not? Does it change when you are not clicking the zoom? (all assuming setfmode.lua has been run prior)

Also, by default (when the "Focus mode" option is set to "Ovr"), setfmode will pick either of AF Lock or MF, and print which was used. You can try the other one by changing the "Focus mode" option in the script menu.

You can also try setting the distance using the script. This isn't likely to be very practical for most real use, but if the override is working, you should see a clear difference between, say 100 and 10000.

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Oh wow, this has a lot of potential in speeding up my workflow on what I'm using this camera for, I'll try it out, who knows, I even might be able to control SD via it. Thanks a lot!

chdkptp uses the same underlying functions to control focus, but it might help with diagnosing the issue.

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LeTomas

Re: Manual Focus on SX620HS not working

« Reply #6 on: 19 / September / 2021, 22:44:55 »

I don't know what happened or what I did different, but it now seems to work (SD overdrive), this was after connecting it to the PTP extension, by using MF mode on script menu, which I had tried before, also yes, PTP will help a lot on what I'm doing, works like a charm

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reyalp

13386

Re: Manual Focus on SX620HS not working

« Reply #7 on: 20 / September / 2021, 00:21:34 »

Quote from: LeTomas on 19 / September / 2021, 22:44:55

I don't know what happened or what I did different, but it now seems to work (SD overdrive), this was after connecting it to the PTP extension, by using MF mode on script menu, which I had tried before, also yes, PTP will help a lot on what I'm doing, works like a charm

Glad to hear it worked.

FWIW, you can do enable MF / AF lock and set focus directly in the chdkptp console if you want. To set MF mode

Code: [Select]

=set_mf(1)

(or set_aflock(1) for AF lock)

To set focus distance to 1000mm (for example)

Code: [Select]

=set_focus(1000)

If MF or AF lock is enabled, the focus should update immediately in the live view when you call set_focus.

A list of CHDK script functions is available at https://chdk.fandom.com/wiki/CHDK_Scripting_Cross_Reference_Page - most of them can be called from chdkptp using =.

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LeTomas

Re: Manual Focus on SX620HS not working

« Reply #8 on: 20 / September / 2021, 13:19:25 »

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you can do enable MF / AF lock and set focus directly in the chdkptp console if you want. To set MF mode

Thanks, what's the difference between MF and AF lock?

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(or set_aflock(1) for AF lock)
To set focus distance to 1000mm (for example)

This looks very useful for consistent results

I've been testing PTP and yeah, it's an immensely useful tool, being able to directly save DNGs on my PC is next level indeed.

Just one last question: is it possible to scale up the Live View screen more than 1:1? for closer inspection on the image when focusing, etc

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reyalp

13386

Re: Manual Focus on SX620HS not working

« Reply #9 on: 20 / September / 2021, 16:19:54 »

Quote from: LeTomas on 20 / September / 2021, 13:19:25

Thanks, what's the difference between MF and AF lock?

The short answer is that they should be pretty equivalent from a CHDK POV, but they are different functions in the Canon firmware and SD overrides tend to have camera specific issues/quirks, so one may work better than the other on a given port.

On many cameras set_aflock does an AF scan before locking focus, while set_mf does not.

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I've been testing PTP and yeah, it's an immensely useful tool, being able to directly save DNGs on my PC is next level indeed.

Just one last question: is it possible to scale up the Live View screen more than 1:1? for closer inspection on the image when focusing, etc

Unfortunately, it is not currently possible. It would be a good feature to add, but the underlying resolution is quite low in any case. You could use lvdumpimg to grab the live view and scale it in another program.

It's possible the "digital teleconverter" setting will give you a magnified view, although it's likely to be digitally upscaled in the live view. This setting would also affect jpegs, but not CHDK raw.

You could shoot jpegs to fine tune focus, but it looks this port doesn't have jpeg remoteshoot support yet so you'd have to use shoot -dl. If you are interested and willing to test, I can probably come up with a test build with jpeg remoteshoot support.

Note that you can also use jpegs to fine-tune focus from code: All else being equal, better focus will produce larger files sizes.

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