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Author Topic: Most reasonable DSLR for multi-cam face capture setup  (Read 110902 times)

Magnus

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #75 on: August 01, 2013, 03:52:24 PM »
Hello all!

Thanks to all of you for the great info!

Andrew, I was just wondering regarding this point about the 600D:

- syncs slower than Nikon, occasional lag inconsistencies

I thought from your testing with the Camera Axe/Multi Flash Plus that the 550D was inconsistent but the 600D was not (when pre-focus command was taken into account)?

Best, Magnus.

Magnus

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #76 on: August 01, 2013, 04:24:45 PM »
Hello again!

I don't know if you guys have run into this or not, but it seems that the D3200 offloads are somewhat slow?
We noticed this yesterday when we only had the Canons in the rig that the transfers with Smart Shooter were much quicker than in the mixed situation. Could be some issue on our end but just wanted to know if anyone else had noticed this? Might be filesize, but the difference seemed quite large for it just being that.

Best, Magnus.

Andrew

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #77 on: August 01, 2013, 04:46:13 PM »
Andrew, I was just wondering regarding this point about the 600D:
- syncs slower than Nikon, occasional lag inconsistencies

I thought from your testing with the Camera Axe/Multi Flash Plus that the 550D was inconsistent but the 600D was not (when pre-focus command was taken into account)?


My tests were not very accurate (I measured against incredibly slow cheap studio flash), so I could only confirm that they are much more reliable than 550D, but I would have to get much faster speedlight and do extensive tests to get more confidence in my findings. In contrast, Lee has been testing and using 600d's in real work scenarios for a good while now and I have a lot of confidence in his claims, so I based what I wrote on his findings (big thanks, Lee!).

Oh, I haven't noticed particularly slow Smart Shooter transfers from D3200, no. Photos take a tiny bit longer (perhaps 20-30% longer) to land on my HDD but files are larger so thats understandable.

-Andrew

Magnus

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #78 on: August 01, 2013, 05:04:38 PM »
Hello Andrew!

Ah, I just thought that the 43ms random lag you observed before pre-focus command was sent seems to go well with the 1/20th limit on the 600D I think Lee mentioned.
Anyways not really an issue for me at all, hehe. I just thought I had misread your post.

Yeah, I am guessing the transfers are due to the old laptop computer we used (we saw like 5-10sec difference, hehe).

Best, Magnus.

scanlab.ca

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #79 on: August 02, 2013, 06:38:26 PM »
Hey all,

I've been following this thread and looked at some sample images coming out of D3200. They do look pretty soft. But don't really represent the quality i'm getting.

I'm attaching another sample image that was taken with d3200, with the following settings: ISO100, f8, 1/25th, Sharpening OFF, Prime lens.

About sharpening. As far as I understand SIFT algorithm does its own sharpening, and a whole array of other post processing manipulations in order to find proper neighbouring edges/pixels. So, leaving this job to camera or other software may actually reduce build quality.

https://dl.dropboxusercontent.com/u/19149582/D3200%20%28000005010712%29_00169.JPG

Now, I do need more light in there, but this should only make things better.


Cheers,
Ruslan Vasylev
Best regards,

Ruslan Vasylev | Scanlab Photogrammetry
S: https://scanlab.ca | E: ruslan@scanlab.ca | T: 1 (778) 991-5157

meshmaster

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #80 on: August 02, 2013, 06:45:09 PM »
Hey all,

I've been following this thread and looked at some sample images coming out of D3200. They do look pretty soft. But don't really represent the quality i'm getting.

I'm attaching another sample image that was taken with d3200, with the following settings: ISO100, f8, 1/25th, Sharpening OFF, Prime lens.

About sharpening. As far as I understand SIFT algorithm does its own sharpening, and a whole array of other post processing manipulations in order to find proper neighbouring edges/pixels. So, leaving this job to camera or other software may actually reduce build quality.

https://dl.dropboxusercontent.com/u/19149582/D3200%20%28000005010712%29_00169.JPG

Now, I do need more light in there, but this should only make things better.


Cheers,
Ruslan Vasylev

Thanks for sharing your results!

A few questions, exactly what lens are you using?

How far is the subject from the lens?

Cheers,

Joe

scanlab.ca

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #81 on: August 02, 2013, 07:01:53 PM »
The subject is approximately 1.3m from the sensor.

I can't really tell which lens it is exactly(we have a few of them, all manual btw), since me and my partner have rearranged the setup, but we're getting pretty consistent results, well maybe except for the slight color tint cause of older lenses and weather conditions they've been kept in.

Also, we're using constant fluorescent light source, no flashing... also notice that crazy long exposure time. :)

I'm not sure how valid the sharpness argument is for Photogrammetry, since the more cheaper cameras you have the closer you can move them in and get that "missing" sharpness-detail back, as well as, capture more parallax angles while at it. Unless the minimum focus distance starts getting in your way.

Best regards,

Ruslan Vasylev | Scanlab Photogrammetry
S: https://scanlab.ca | E: ruslan@scanlab.ca | T: 1 (778) 991-5157

Infinite

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #82 on: August 02, 2013, 07:15:56 PM »
The subject is approximately 1.3m from the sensor.

I can't really tell which lens it is exactly(we have a few of them, all manual btw), since me and my partner have rearranged the setup, but we're getting pretty consistent results, well maybe except for the slight color tint cause of older lenses and weather conditions they've been kept in.

Also, we're using constant fluorescent light source, no flashing... also notice that crazy long exposure time. :)

I'm not sure how valid the sharpness argument is for Photogrammetry, since the more cheaper cameras you have the closer you can move them in and get that "missing" sharpness-detail back, as well as, capture more parallax angles while at it. Unless the minimum focus distance starts getting in your way.

Hi Ruslan,

The photo is nice but it's are still very soft compared to a Canon output.

http://www.ir-ltd.net/uploads/01_Camera-901.JPG

Sharpness and contrast is critical with Photogrammetry if you want to get consistent highly detailed scans. Any kind of blurring or softness will ruin the scan output. Unless you only require a medium resolution scan.

Continuous lighting is very hard to capture with, unless you have super bright (Lightstage dark contact less bright!) output.

I've run many tests with the D3200 and they just fail in comparison to the 600D.

Have you tested with Canons?
« Last Edit: August 02, 2013, 07:17:33 PM by Infinite »
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meshmaster

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #83 on: August 02, 2013, 07:23:46 PM »

It's also interesting that your lens details are omitted from the EXIF data.

Mind you, I'm not trying to imply anything by saying this...rather, I'm trying to point out that it is near impossible to draw any conclusions regarding the viability of the D3200 unless all the variables are known.

After all, if you are using a prime lens that cost $1000 to achieve these results it pretty much makes the point of even using this camera in the first place moot.   ;)

Cheers,

Joe

meshmaster

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #84 on: August 02, 2013, 07:54:27 PM »
Some interesting image comparisons between the Nikon D3200 and some other cameras can be found here.

http://www.imaging-resource.com/PRODS/nikon-d3200/nikon-d3200A.HTM

Scroll down the the "Image Quality" Section in particular.

Cheers,

Joe
« Last Edit: August 02, 2013, 07:56:00 PM by meshmaster »

scanlab.ca

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #85 on: August 02, 2013, 07:59:37 PM »
Hey Lee,

Your image does look super crisp.
We'll be testing d3200 at f13 soon with Flash and see how it performs.

But, my main point was that there are multiple ways of capturing sharpness. It no longer is a factor of one single camera, but of all cameras working in conjunction to produce the best result.

I look at it as a balancing act.
The problems we're solving are sort of different it seems.

For those who are at 40 cams or less the main issue is the number of angles we can capture. Cause what good is a sharp camera when you have to rotate the subject and it moves accidently. The geometry build screws up and all the sharpness of a few cameras will be smudged by this one flop.

Best regards,

Ruslan Vasylev | Scanlab Photogrammetry
S: https://scanlab.ca | E: ruslan@scanlab.ca | T: 1 (778) 991-5157

scanlab.ca

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #86 on: August 02, 2013, 08:05:23 PM »

It's also interesting that your lens details are omitted from the EXIF data.

Mind you, I'm not trying to imply anything by saying this...rather, I'm trying to point out that it is near impossible to draw any conclusions regarding the viability of the D3200 unless all the variables are known.

After all, if you are using a prime lens that cost $1000 to achieve these results it pretty much makes the point of even using this camera in the first place moot.   ;)

Cheers,

Joe

Oh wow, I'll take that as a compliment!

The image was most likely taken with a regular manual  f/2.8, 50mm Nikkor lens which goes for around $50-$70. It is a manual lens hence no EXIF data, so we do our own calibration on these lenses.
Best regards,

Ruslan Vasylev | Scanlab Photogrammetry
S: https://scanlab.ca | E: ruslan@scanlab.ca | T: 1 (778) 991-5157

meshmaster

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #87 on: August 02, 2013, 08:13:10 PM »

It's also interesting that your lens details are omitted from the EXIF data.

Mind you, I'm not trying to imply anything by saying this...rather, I'm trying to point out that it is near impossible to draw any conclusions regarding the viability of the D3200 unless all the variables are known.

After all, if you are using a prime lens that cost $1000 to achieve these results it pretty much makes the point of even using this camera in the first place moot.   ;)

Cheers,

Joe

Oh wow, I'll take that as a compliment!

The image was most likely taken with a regular manual  f/2.8, 50mm Nikkor lens which goes for around $50-$70. It is a manual lens hence no EXIF data, so we do our own calibration on these lenses.

LOL!  You see, I knew that you might take my comment in the wrong way  :-[

But honestly, you should take my comment as a compliment because your image is quite an improvement over what I am seeing with the D3200 and the standard kit lens.   I'd be interested in seeing what sort of results you would get using a similar setup and the 18-55mm kit lens at a distance of 1 meter using the 18mm setting.

Thank you for providing some further details about the lens you are using... now that is a lot more helpful.

Again, I didn't mean to cause insult or offence.... just trying to compile all the facts  :)

Cheers,

Joe
« Last Edit: August 02, 2013, 08:14:58 PM by meshmaster »

meshmaster

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #88 on: August 02, 2013, 08:42:11 PM »

Ok,

I've have my 1960s' vintage Nikon F with a Nikkor-H 1:2 f=50mm prime lens.

I slapped it on my D3200 body and this is what I get:

https://dl.dropboxusercontent.com/u/38398338/D3200/DSC_0006_DxO_50mm_NikonF.jpg

Cheers,

Joe

bernie wempe

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Re: Most reasonable DSLR for multi-cam face capture setup
« Reply #89 on: August 02, 2013, 08:49:23 PM »
hi all,
i'm Ruslan's business partner and just wanted to add we're using the Nikon 50mm f/1.8 E pancake lens in that shot he posted.
thanks for sharing info and helping us get our heads around theses D3200's.