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H4D-200MS

fotografz

Well-known member
The samples are mind blowing. Like nothing I've ever seen ... truly a world class studio machine that can be used for everyday shooting when desired.

The camera operates as a 50 meg single shot, 50 meg 4 shot and 200 meg 6 shot. :eek:

Having used a multi-shot before, I can say this has to be the highest IQ "usable" studio camera I've ever seen.

Multi-Shots are a blast to use BTW ... my puny 39 meg MS was spot on for color accuracy and virtually eliminated retouching issues and moire' ... so I can't imagine what this pup will do.

-Marc
 
The samples are mind blowing. Like nothing I've ever seen ... truly a world class studio machine that can be used for everyday shooting when desired.

The camera operates as a 50 meg single shot, 50 meg 4 shot and 200 meg 6 shot. :eek:

Having used a multi-shot before, I can say this has to be the highest IQ "usable" studio camera I've ever seen.

Multi-Shots are a blast to use BTW ... my puny 39 meg MS was spot on for color accuracy and virtually eliminated retouching issues and moire' ... so I can't imagine what this pup will do.

-Marc
Glad you like Marc! :thumbup:

We love the products capabilities and it was received very well at the test sites.

David
 

bensonga

Well-known member
I am really impressed with the products Hasselblad has been coming out with recently. If I could afford a new high end MFDB system....it would be an H4D-xx, for sure. This one is amazing.

Gary
 

BradleyGibson

New member
The 200MS looks amazing.

I'm trying to figure out if the 6-shot uses any interpolation. I've read the PDF on how it exposes and I'm still a bit confused.

First, I'm assuming a bayer pattern:
GRGR...
BGBG...
...

Shot #1: Unshifted, looking at the upper left corner pixel, we'd get the green channel.
Shot #2: Shift up one pixel and now you'd have the blue channel at the upper left corner.
Shot #3: Shift one pixel to the left from the original position and now you'd get the red channel as well. Now we have full color for (almost) every pixel position for a 50MP shot.
Repeat the above process 1/2 a pixel to the right, 1/2 a pixel down, and 1/2 a pixel right and down. That gives me a minimum of 12 shots (16, if we want 2x oversampling on the green channel which can be useful). How is it possible to get double the horizontal and double the vertical resolution without interpolation in only 6 shots?

David, can you help?

Thanks,
-Brad
 

Arjuna

Member
from the press release, e.g. dpreview: "The H4D-200MS uses an extension of the company's sensor-shift, multi-shot (MS) technology to create a 200 megapixel file from six images taken at slight offsets. It can also use the four-shot mode used by the H4D-50MS that shifts the sensor by one pixel in each direction to capture all colors at each position. The latest approach adds 1/2pixel offsets to increase the captured resolution to 200MP."

The four one pixel shifts gives you a non-Bayer 50 MB: each image pixel get sampled by red, green, blue, and green sensor pixels. The same four shifts at 1/2 pixel offsets would give you the 200 MB of resolution, but each image pixel has one sample direct from a (red, green or blue) sensor sample, and three samples that are each from half way between two sensors. If you kept just the direct samples, you would have a 200 MB Bayer image. My guess is that the three intermediate samples would give you better than Bayer colour, but not quite the true colour of the standard (50 MB) MultiShot, hence the two extra shots/samples in order to be able to calculate a true colour, i.e. non-Bayer, 200 MB image. Just a guess.
 
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BradleyGibson

New member
I think I just figured it out.

Shot 4: shift sensor to the right of original position by 1/2 pixel. This gives green value of second pixel in the first row of the final image.
Shot 5: shift sensor up by 1 pixel from previous position. This gives blue value of same pixel.
Shot 6: shift sensor 1 pixel left from shot 4 position. This gives red.

These last three shots were all offset from the first three by half a pixel, so almost all pixels will have all three colors sampled (two edges at the edge if the sensor will be incomplete, but they could be easily discarded).

Not sure if that makes sense in text, but it seems to work, to my mind, at least. Clever!

Best regards,
Brad
 

etrigan63

Active member
I have seen demos of the multi-shot system and it is all controlled by Phocus. This is a tethered camera setup. Phocus calls the shots and combines the images automagically.
 
I think I just figured it out.

Shot 4: shift sensor to the right of original position by 1/2 pixel. This gives green value of second pixel in the first row of the final image.
Shot 5: shift sensor up by 1 pixel from previous position. This gives blue value of same pixel.
Shot 6: shift sensor 1 pixel left from shot 4 position. This gives red.

These last three shots were all offset from the first three by half a pixel, so almost all pixels will have all three colors sampled (two edges at the edge if the sensor will be incomplete, but they could be easily discarded).

Not sure if that makes sense in text, but it seems to work, to my mind, at least. Clever!

Best regards,
Brad
Hi Brad,

Basically the 6 shot does the same 4 shots as the Multi shot (RGBG) and then a half pixel movement in both directions.

Product Management are writing up a clearer tech explanation and I will post it here when ready.

David
 
How long does the process of taking the six shots that make up one image take? Is it all automatic?

Quentin
Hi Quentin,

It is indeed all automatic and the 6 shots are covered pretty quickly. If you have decent flash equipment that recharges fast enough then there is only a second or so between each captures.

Older flashes that need longer to recharge or reach a better stability can be helped out by adding a flash delay to slow the capture rate down.

Assembly of the six shot is wholly dependant on how powerful your machine is.

David
 

fotografz

Well-known member
Basically, Multi-Shot doesn't add much time to your capture process but saves huge amounts of time in post work ... especially if you are outlining anything, or if shooting items where color accuracy is critical ... plus no moiré issues with intricate patterns.

The tethered work flow is exactly the same as with a single shot ... all test shots to adjust lighting and composition, or discussion with clients /art directors are done single shot, then when ready to shoot the final image you just click the MS icon in Phocus and the software takes command. You do not even have to adjust the lighting, it is all figured out and exposed correctly.

As David said, there is a section in Phocus that allows you to set the flash delay to accommodate your specific strobe gear's capability, or the level which you have set the lighting as it relates to recycle times. I had my CF/39MS set to a 4 or 5 second delay between each shot because I often max'ed out my strobe system shooting stopped down for DOF. With other applications I could set it to shoot faster.

-Marc
 

Quentin_Bargate

Well-known member
Sounds impressive! Not sure I need it as my H4D-50 does what I need already, but that is not to say I don't want it :D

Quentin
 
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