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Author Topic: Most reasonable DSLR for multi-cam face capture setup  (Read 70728 times)

Andrew

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Most reasonable DSLR for multi-cam face capture setup
« on: July 24, 2013, 01:39:01 PM »

Nikon D3200 seems to be the camera of choice these days, replacing Canon 600D, with main rationale behind it being price advantage over 600D, but also, to quote Lee on FB, "These things are as quick as gunslingers! Very fast and perfect sync compared to 600D's".

Now, I understand the price factor all too well, but speed? Can anyone (Lee? :)) explain what that means specifically with respect to 3D scanning?

With devices like Shutter Cell/Camera Axe/Multi Flash Plus, one can precisely synchronize cameras with flash units, no matter how big the shutter lag is (btw. D3200s shutter lag is larger than D600s), as long as shutter lag is consistent. To me both D3200 and 600D seem to have consistent shutter lags but I didn't have time/means to do very precise tests yet - I can only confirm they are both light years ahead of old Canon 550D.

So:

1) Is D3200's shutter lag much more consistent than 600Ds?

2) Are there any other important speed/synch factors I am missing?

3) Isn't D3200 a tad soft for precise 3D reconstruction? Does sharpening photos help?


Oh, just to be clear, this is all for internal indie studio use, I am not about to offer scanning services and poach anyone's business :) Also, I only do occasional scans so convenience (battery bay doors blocked by camera mount etc.) are of secondary importance, although it would be nice to hear all known pros and cons.

Thanks in advance!
Andrew

andy_s

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #1 on: July 24, 2013, 10:31:56 PM »
Hi Andrew,

unfortunately no answers - just exactly the same questions.

Read this somewhere:

...The results from the D800e are about as good as one can expect from the process, or so I thought until a brand-new Canon SL1 fell into the mix. The results from this 18MP dwarf SLR with kit lens are nothing short of amazing. Small size, hair, eyes, clean data, and an easy to control standard remote control port, we’ve found our camera, I believe, for the new portable human body scanning unit...


Infinite

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #2 on: July 25, 2013, 02:13:20 PM »
I can confirm from my own tests, the D3200's are not as useful as I had hoped. Testing with 8 cameras looked good but then scaling to 24x I saw inconsistencies with syncing at fast speeds.

The problem I have found overall with Nikon image output is, they are damn soft. No matter the settings or lighting. With this type of photogrammetry you are stuck with camera exposure settings and lighting style and this can really show off the differences between camera types. I've only tested with Canon 550D and 600D but they are far superior in image quality compared to the Nikon D3200's D7100's and D800's, even the D800E (this nonsense about moire filter removal and sharper images is utter crud, marketing ploy) the same with the D7100. The same softness appears.

At this stage I would recommend 600D but the best thing always is... find out on your own and not trust some nut on the internets :)

Also:

The D3200 trigger leads are tricky to find, power easy but the supplied data leads are useless at about 24cm long. Trying to source longer USB leads is hard as they have a special connector to interface with the body, not a simple USB2 mini jack like Canon. Any leads over 5m and you will have drop outs so, 2m-3m is recommended, same with Canon's.

It's about damn time camera manufactures utilized USB3 to cover this distance limitation. D800's being the only I know of so far.
« Last Edit: July 25, 2013, 02:18:19 PM by Infinite »
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meshmaster

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #3 on: July 25, 2013, 02:41:03 PM »
Sad but true... I've learned this the hard way as well.  I was also pretty pleased at first with the Nikon D3200 until that is I started to realize just how poor the image quality is when compared to the Canon's.  I agree, don't be taken in by high mega-pixel numbers and marking spin.  The focus on the Nikon D3200 is shockingly soft... which is very disappointing indeed.

Cheers,

J

Infinite

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #4 on: July 25, 2013, 02:47:44 PM »
Sad but true... I've learned this the hard way as well.  I was also pretty pleased at first with the Nikon D3200 until that is I started to realize just how poor the image quality is when compared to the Canon's.  I agree, don't be taken in by high mega-pixel numbers and marking spin.  The focus on the Nikon D3200 is shockingly soft... which is very disappointing indeed.

Cheers,

J

How many do you have to sell on Joe? Sorry if my previous hype egged your choice on but as you know, personal research and testing is the only way to find out for sure. Same with projectors  ???

The problem with multi cameras as well is, you can test with 4 or 8, that's hard enough and teasing with results but you only really find out what happens when you go higher, like 40 or 80+. Unknown territory.
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meshmaster

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #5 on: July 25, 2013, 03:01:34 PM »
Hi Lee,

Luckily, I only have 8 D3200's.... so things could have been far worse  :-[

Cheers,

J

Infinite

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #6 on: July 25, 2013, 03:14:03 PM »
Hi Lee,

Luckily, I only have 8 D3200's.... so things could have been far worse  :-[

Cheers,

J

If it's any consolation I have 28x D3200's and 8x D800's!

Multi-Camera Photogrammetry is a big boys game and you have to gamble.
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meshmaster

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #7 on: July 25, 2013, 03:20:53 PM »
I totally understand!

The business of high-end scanning takes titanium bollocks... but nothing ventured, nothing gained  :)

One thing is for sure, I'll be returning to Canon for the next lot that I purchase... that is unless something major changes between now and then.

Cheers,

J

andy_s

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #8 on: July 25, 2013, 03:23:39 PM »
Appreciate the info Joe / Lee.

Anything you can share about the [to me] remaining mystery:

"These things are as quick as gunslingers! Very fast and perfect sync compared to 600D's;)
« Last Edit: July 25, 2013, 03:39:21 PM by andy_s »

Wishgranter

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #9 on: July 25, 2013, 03:27:17 PM »
My worlds about consultancy with Lee have been right  ;)....
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Infinite

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #10 on: July 25, 2013, 03:35:44 PM »
I totally understand!

The business of high-end scanning takes titanium bollocks... but nothing ventured, nothing gained  :)

One thing is for sure, I'll be returning to Canon for the next lot that I purchase... that is unless something major changes between now and then.

Or a straight jacket and padded cell :)

It pains me to say it but Canon are better with regards to image output, shoddy design though.

Appreciate the info Joe / Lee.

Anything you can share about the [to me] remaining mystery:

"These things are as quick as gunslingers! Very fast and perfect sync compared to 600D's;)

There's no mystery. These cameras are very fast! you can sync better than the 600D's but over a certain amount of cameras, so far 24x tested, syncing becomes harder. Meaning some black images. By syncing I mean syncing flashlight up to 1/250th speed. You can' t do this even with 600D's at such speeds. Anything above 1/20th becomes hard and you get black images. Fast syncing is useful for multi-lighting.

D800's have so far been the best but even then I would bet at 24x the same thing would happen. Slow sync is much easier at 1/4 in general. But this is slow.

My worlds about consultancy with Lee have been right  ;)....

There's so many little things to get right when building a system. So many quirks to control!
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meshmaster

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #11 on: July 25, 2013, 03:41:22 PM »
There's so many little things to get right when building a system. So many quirks to control!

This is the TRUTH!

Cheers,

Joe

andy_s

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #12 on: July 25, 2013, 04:52:16 PM »
Appreciate all the comments.

Andrew, my understanding of this:

"...so far 24x tested, syncing becomes harder. Meaning some black images. By syncing I mean syncing flashlight up to 1/250th speed. You can' t do this even with 600D's at such speeds."

Is that the variability of shutter lag [across 24 cams] is always greater than 4 millisecs i.e HIGH speed is being referred to as a low variability of shutter lag.

So, if you're not using multi-light then just use a long-exposure [from dark] together with a pack of 550D's ?
« Last Edit: August 12, 2013, 12:03:58 PM by andy_s »

Magnus

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #13 on: July 25, 2013, 05:06:17 PM »
Hello All!

Thanks so much to you all for sharing this information!

Lee, the trouble over 1/20th sync with 600D is that also with mirror lock-up?

Could it also be related to pre-focus?

Also I assume you guys mean the jpg quality of the D3200? The raw out of it is from my (limited) testing very good (which I actually don't use, hehe).

Best, Magnus.

meshmaster

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #14 on: July 25, 2013, 05:09:08 PM »


Also I assume you guys mean the jpg quality of the D3200? The raw out of it is from my (limited) testing very good (which I actually don't use, hehe).

Nope, in my case I am referring to the RAW quality which is vastly inferior to that of my Canon's.  Honestly, the image quality of D3200 is shockingly poor in comparison.

RAW or JPEG the focus is still very, very soft.

Cheers,

Joe
« Last Edit: July 25, 2013, 05:16:20 PM by meshmaster »