Messages

16

General / Re: What cameras/lenses are preferable for photoscan?

« on: October 12, 2013, 06:19:32 PM »

... you're such a source of information!

I'm not so sure, just trying to help. Please also treat any thing I say with healthy skepticism [none of it is based in practice].

Surely many things count - including MPix. Those A3300's that Chad uses are 16Mpix.

E.g, this from 'Infinite' [Lee] for DSLR's http://www.agisoft.ru/forum/index.php?topic=942.msg4645#msg4645

"...anything below 18MP really isn't great. You get OK results with 12MP but it's not ideal."

Re aperture, this from chdk guru 'reyalp' [in answer to, yet another, newbie query by me] http://chdk.setepontos.com/index.php?topic=8769.msg106057#msg106057

"Some have adjustable aperture, some don't. Most of the ixus and recent A series do not."

I'm currently 'battling' through this topic from the German CHDK site - chrome tries well at the translation but it misses some stuff. More generally, the thread does show that chdk multi-cam implementations are far from straightforward http://forum.chdk-treff.de/viewtopic.php?f=20&t=2037   

Finally,

Some further excellent advice on that aforementioned post from Lee:

"...The key is sharp, focused, contrasted images. As much detail as possible, for good reconstruction.

Ideally you want access to USB, trigger and continuous power for your devices. Once they are running it's best not to have to physically touch them again, until you shut down. This way you can re-use camera alignments (very effective)."

I remember looking at 'dummy' batteries for some Canon P&S that don't have external power available - but can't find the link [just one more important point to consider]

Looking forward to more of your progress 

PS: I haven't read [much] about ptpcamgui and don't plan to.

17

General / Re: What cameras/lenses are preferable for photoscan?

« on: October 12, 2013, 02:24:55 PM »

I'll leave SDM and additional hardware for the future, I think i'll go the usbremote way for the moment and if things don't go as expected I'll have to call the SDM chivalry. Thx for your help!

Hi ikercito - the RC receiver / proSDM solution is [probably] only useful if a totally wireless triggering / tethering solution becomes possible / is required. Even then, I don't think the 'synch' would be as good as using any better than a simple 'button switch', as Chad first described here http://www.agisoft.ru/forum/index.php?topic=1378.msg7164#msg7164.

The caveat is -

It was then 'EMULAT3D' who suggested switching via the powered hub here http://www.agisoft.ru/forum/index.php?topic=1378.msg7179#msg7179- however, i'm not sure if the added circuitry within the powered hub [above that of the simple 'button switch'] results in voltage decay timing variances between each hub outlet.

There is also this to consider [for both hub / simple 'button switch' solution] http://chdk.setepontos.com/index.php?topic=8769.msg105454#msg105454:

"5/ However you have to be aware of a another potential problem, that in a "Standard" Sync USB cable there is no "Discharge" path, except for the camera's internal non linear circuits. This has been a subject in several previous posts and dosn't appear to be a problem with twined cameras but could be major problem with your rig that has a combination of long USB cables and 50 cameras."

Anyway, I hope the hub solution results in adequate results for you - it definitely has the benefit(s):

• simplicity
• allowing image transfer [non-trivial, admittedly] as described by EMULAT3D [link as above]..."Then to pull the images off (still a pain and not ideal) we would just disable remote trigger on the cameras, then connect the hub to the PC to retrieve images (via Windows Picture Import). This is nice because you can then tag the images to a specific camera number."

After the actions at point 2 above the camera is back in a state that you could 'program' image transfer by client chdkptp lua script - but, initially, learning this will be time consuming [for me also] and not particularly productive - unless you get round to implementation of the hack I described at reply #20 in this thread.

What camera model are you using ? [hope i'm not asking for info already posted  ]

18

General / Re: What cameras/lenses are preferable for photoscan?

« on: October 09, 2013, 10:01:30 PM »

Hi ikercito,

I hope the following does not confuse more [rather than less]...

I think the 40ms you're talking about was related to programatic 'chdkptp' based sync [not chdk 'usbremote' sync  - which is based on the voltage change on the +5V line, as Chad has been using].

To my understanding the chdk usbremote version synch should be much better tighter than the chdkptp figure  - but since Chad is not experiencing that i'm not yet sure what the problem is.

Might it be:

• CHDK releases seem to be referred to as 'stable' and 'experimental' - I know there are sometimes big differences. The stable [old] stuff was, on many occasions a spaghetti of code - the more recent 'gurus' have tried to straighten that out, maybe improving performance as well ? So maybe Chad's version is the stable [old] version ?
• I also think I remember reading that newer digic processors have poorer usbremote sync than older versions [but I can't find that link and I have a bad memory so could have got that logic reversed  ]

Gee, I just read this so far, it is a bit of a muddle  , maybe I should stop now...

Edit:
To be aware of http://chdk.setepontos.com/index.php?PHPSESSID=60d7bd280df3b229f8773b19f6ae5992&topic=6972.msg90560#msg90560

Quote
I have a current setup with an old Canon camera with CHDK, and chdkptp running, that's not a problem.

The A3300 was ported by somebody with no programming background.  The current notes.txt file says that the USB functions have not been tested.   It seems to be fine but it is probably not the most complete CHDK port.


Other 

If the chdkptp [e.g. multicam.lua] is currently too much to take in and you just want to use chdk usbremote sync [but without any wires between cameras] you can [for each camera] connect an RC receiver to one of these:

http://www.gentles.ltd.uk/gentstereo/sdm.htm [gentSTEREO-proSDM]

so,

• connect the RC receiver to the 'Trigger input (3.5mm mono jack)' and then
• connect the gentSTEREO-proSDM usb output to the camera usb input.

The designer of this little unit says:

"There is no problem getting a synch of a fraction of a millisecond with dozens of cameras fired wirelessly. You use a single receiver whose output is plugged into the jack socket of the gentLes switch. That is what it is for, I designed it.".

Of course you'll need to also purchase a single RC transmitter to trigger all your cameras with this setup.

An interesting thing about each 'gentSTEREO-proSDM' unit is that it also has a:

'TRIAC flash output (2.5mm mono jack) variable between 2 and 50mS after the shutter release. Will trigger virtually any stand-alone flash unit.'   

An uninteresting thing about each 'gentSTEREO-proSDM' unit is that it is, relatively, expensive.

Of course [because this is unrelated to chdkptp] none of this helps with Chad's problem:

"...the trouble of having to switch each camera in and out of USB remote mode"

Neither does it allow chdkptp programmatic image retrieval [either instantly - directly over usb or from the SD card over usb]

Finally

IF chdk guru 'reyalp' get his wifi version of chdkptp going - it frees up the usb camera input for the RC receiver / 'gentSTEREO-proSDM' chdk usbremote, described above.

Since we now know the chdk gurus have already figured out co-existence of chdk usbremote and chdkptp that holds out the possibility of a totally wireless P&S triggering / tethering system. All you need now is to have external power supplies [or hack connection to external external power supplies] and the entire system might go mobile. 

Place your bets - but I [Edit] know think i'll be buying a couple of wifi enabled Canon P&S to start [Edit: or maybe not, if I can't find one with a usb connector onboard as well suitably 'ported'  ].

19

General / Re: 3D printing - Mcor

« on: October 08, 2013, 10:37:33 PM »

It's a pity Wishgranter.

Mcor is just down the road from me a 'wee' bit - i'll try and remember to phone Conor or Fintan soon and make them hurry along.

I hope they gave you bed & breakfast during the 60 hour wait 

Looking forward to seeing the prints...

20

General / Re: What cameras/lenses are preferable for photoscan?

« on: October 08, 2013, 11:10:10 AM »

Hi Chad, if neither flash nor precise synch is are required then 'pioneering' may be optional - chdkptp [with just a powered usb hub network] might be able to do it all as things currently stand [no need to toggle the 5V on the usb line] - see this post:

http://chdk.setepontos.com/index.php?topic=8769.msg105281#msg105281



"This is quite exciting for me, but now I wonder how to make the cameras shoot at once. Is there a way to bring the camera into a "ready-to-shoot"-mode, like the one I have when applying 5 Volt to the Y-cable I use together with CHDKs USB remote function. And then fire them all at once or with a very short delay?

Do you have any suggestions how to achieve a multi-camera-shooting with chdkptp?

You can do this using the multicam.lua module included with chdkptp (it's not really finished, some coding may be required), but the synchronization will be not be very good compared to a properly functioning USB remote trigger, several tens of ms at best.

I've never tried it with more than two cameras. See http://chdk.setepontos.com/index.php?topic=6231.msg81330#msg81330 and comments in the source."



I previously posted the link to the multicam.lua code here http://www.agisoft.ru/forum/index.php?topic=1559.msg8182#msg8182

21

General / Re: What cameras/lenses are preferable for photoscan?

« on: October 07, 2013, 08:40:34 PM »

I'm still in the middle of trying to figure out all the links Chad - but I think most everything is possible.

See this for example:
http://chdk.setepontos.com/index.php?topic=10220.msg101814#msg101814

Resulting in this:

http://chdk.setepontos.com/index.php?topic=10220.msg105268#msg105268

[as stated that needs some custom electronics and (perhaps) a custom CHDK build]

Until recently the 'simultaneous' use of chdk usbremote and chdkptp had not been understood however, it now seems that nut may have been cracked [even though I don't yet fully understand how to put this into 'operation'] - see this post:

http://chdk.setepontos.com/index.php?topic=8769.msg105488#msg105488

The last bit that [I think that] I need to understand is the integration of DSLR / studio flash by use of the camera-axe, see this post:

http://www.dreamingrobots.com/forums/viewtopic.php?f=8&t=44&start=10#p9032

- no responses yet, but it can't be that difficult 

I just really need to decide on a p&s camera model [& a copy of photoscan, finally !] and start some serious investigations - but then interesting [4D ?] discussions like this http://chdk.setepontos.com/index.php?topic=10256.msg103467#msg103467  come along and I start wondering how many HD video FPS the camera has  [or the one about chdkptp over wifi previouly mentioned] and the purchase decision resets 

At the minute my priority is understanding more fully chdk 'precision synch [e.g what builds / what cameras / digic processors etc].

The chdk forum is more like a computer science website - very interesting but also very frustrating [for me]. Still, I think [hope] a further time investment in it will eventually pay dividends. 

With Lee as inspiration - whatever the solution, [I believe] it needs to be super-slick / reliable to be taken seriously in a production environment...I hope it's possible. I hope there's more to follow 

22

General / Re: What cameras/lenses are preferable for photoscan?

« on: October 07, 2013, 02:00:28 PM »

Some people have also used PTP functionality to control their cameras, but once again, I'm not sure if there is a tool out there for solid multiple camera support:

http://chdk.wikia.com/wiki/PTP_Extension

Hi Chad,

early days, and many gremlins, but it looks like chdk guru 'reyalp' is on track to implement his ptp client over wifi. Technical - but very interesting http://chdk.setepontos.com/index.php?topic=6231.msg106005#msg106005 

23

Face and Body Scanning / Re: First Face Scan, need tips

« on: September 20, 2013, 01:38:07 PM »

Hi Manuel,

the Camera-Axe guys that take pictures of bursting balloons / bullets and the like all do it in dark rooms. The balloons don't mind the dark conditions but your subject might ?

I don't have any cams yet and haven't read about that funcionality - but, from a synch perspective it sounds fine.

From what I gather chdkptp client 'lua' code can be written to do just about anything - see this as an example that does not use the chdk usbremote previously referred to [but note in the listing "experimental code for shooting with multiple cameras not optimized for best sync, lots of loose ends"]   

http://trac.assembla.com/chdkptp/browser/trunk/lua/multicam.lua

24

Face and Body Scanning / Re: First Face Scan, need tips

« on: September 19, 2013, 04:31:45 PM »

Chdk usbremote seems to be very nice to sync point to shoot cameras 0,1 milisec (Thats if you have only point to shoot cameras in the rig)
- But how do you sync point&shoot and dslrs ? thats what must be investigated right ? 

Correct - integration needs further investigation

chdk usbremote [the program running on from each cameras SD card]:
As you know, all the cameras wait to 'open' the shutter(s) until after the usb line drops to zero, for some camera types the time to open the shutters [of many cameras] appears to be very synchronised.

Part of what I don't yet know is if the delay period [until all the shutters are synchronously 'open'] is consistent across sequential shots. I suspect it isn't and that would hobble my DSLR integration plan. 


Update http://chdk.setepontos.com/index.php?topic=10687.msg105197#msg105197

"The standard USB remote code is capable of very precise shutter release timing if you use the right sequence.  With the switch mode set to "One Press" and "Sync" enabled, have your Arduino assert the 5V line prior to when you need to release the shutter and hold it high.  When you want to shoot,  set the 5V line to 0V.  You should get a shot less than a few milliseconds later and that delay will be very consistent from shot to shot."

For argument, assume it is a consistent period [update: not necessarily a big assumption any longer].
[I think] A 'relay' controller will be needed to open the USB network +5V lines to all the [point&shoot] cameras [to initiate the chdk usbremote firing sequence] . At that same time [or even before it depending on the DSLR shutter lag ] the controller must also provide an input signal to the camera-axe. As you [again] probably know, the camera-axe has chainable & programable flash / DSLR remote shutter outputs. In theory, that's Job Done    

- Breeze software or Smartshooter / Phase one capture one is nice for tethered multi camera shooting but its only for DSLR's if im correct.

Yes - smartshooter for DSLR cameras [I just think Breeze is too pricey] and chdkptp client [for Windows] for point&shoot [free  ]. A bit of filenaming automation needed for the downloaded files.

- Not sure how you want to use the arduino relay could you explain this a little bit more ?

that's the controller referred to above.

I guess this is offtopic, but why would you prefer the eos100d over the 600d ? its like 50 euro more expensive i think.

see the last part of the link referred to here http://www.agisoft.ru/forum/index.php?topic=1411.msg7127#msg7127

germination process is slow,  but satisfying 

in my case very slow - interesting nevertheless 

25

Face and Body Scanning / Re: First Face Scan, need tips

« on: September 19, 2013, 02:19:35 PM »

Would it be possible to combine for example, cameras with higher resolution for the main facial features of the head, and that point-to-shoot camera rig for the rest of the head ? (or maybe less important features) That would save a lot of money
For smoother results i could subdivide the mesh afterwards in ZBrush. Maybe tweak something.

I don't see why not Manuel - please have a look at some of Magnus's posts - he's getting great results with mixed 1100D [12MPix] & D3200 [24Mpix]. I still can't quite get my head around how photoscan works [apparently] so well with 'mixtures'. 

I'm actually thinking of a total point&shoot solution to start with [head/body - the lot] with a built in migration plan leading to mixed point&shoot / DSLR leading to full DSLR [if required]. That needs a bit more google / development though to hang it all together - chdk usbremote / chdkptp / arduino relay controller / integration signal to camera-axe for studio flash / dslr remote shutter release / smartshooter tether [and maybe a few prayers too  ]. The EOS100D looks quite tasty for the head shots.

I just need to 'pull the finger out' and germinate some of those thought seeds into the real world.

26

Face and Body Scanning / Re: First Face Scan, need tips

« on: September 19, 2013, 09:52:03 AM »

1m distance and you work on approx 50micron precision/deviation per pixel ( 18Mpix image ) so even slightes movement is problematic as Meshmaster wrote even about the multicam setup.....

Yes, I should have also said a multi camera setup using bright enough lights (either from strobe or continuous sources) to provide for reduced lens aperture and high enough shutter speed to eliminate movement from photos. Rock solid camera mounts and stands are also most helpful in reducing any wobble and shake :-)

Cheers,

Joe

Hi Mfranquelo, Joe's [very correct] comment just reminded me [to remind you] that Chad is already getting pretty decent results using a small[ish] number of highly synchronised point&shoot here http://www.agisoft.ru/forum/index.php?topic=1378.0 and no flash [small sensor/large depth of field/larger aperture?], I can't remember if the exposure time was stated anywhere [on a related post] ?

I don't know the lighting for this http://www.martin-hoppe.com/indexMAIN.html - I believe it used 50 usb synchronised point&shoot.

[in my opinion] You shouldn't apologise for being 'persistent' - all this will only become easy when you 'know how' [and maybe not even then ]...I admire persistence [maybe above everything] but I still haven't [much of] a clue 

27

General / Re: Python Scripting Automation

« on: September 03, 2013, 12:49:33 AM »

[I hope] It'll be just a few more months Alexey - have to say, there's a few OOP concepts I never quite got my head around [got stuck a few years ago about half-way through a book 'PHP Objects, Patterns and Practice' - never did finish it  ] - so, I might just have to take you up on your kind offer  .

Maybe a bit of good old-fashioned procedural stuff might can do the bulk of it   

28

General / Re: Python Scripting Automation

« on: September 02, 2013, 11:48:27 PM »

Thanks 7eicher 

29

General / Python Scripting Automation

« on: September 02, 2013, 11:07:06 PM »

Apologies,

haven't got time to read the reference [or look at previous forum postings] at the minute.

Might anyone be so kind as to comment - after securing the images can most all processing steps be automated via python scripting ?

 

30

General / Re: Compact Canon CDHK RAW & Lens Distortion

« on: July 28, 2013, 06:00:59 PM »

Thanks for the info EMULAT3D !