More megapixels through stitching

I shoot with a Canon 50D (15 MPix - ~4700 X ~3100), and a client has asked for 12000 X 12000 px images for a poster for a trade show exhibit. She wants 300 DPI at 40" X 40" because customers will be seeing the posters up close. The pictures are of a product about the size of your finger, so we're looking at 40-60X life size.

I shoot with strobes in my studio, so renting an LF camera and scanning back is not practical.

What are my options for taking perhaps a 3 image X 4 image matrix and stitching? That would yield an image well over her 144 MPix requirement.

How do I index both vertically and horizontally when taking a high-rez matrix picture?

Or, how can I convince the client that she doesn't really need 144 MPix for a 40in X 40in image?

Thanks,

Charles L Webster said:

I shoot with a Canon 50D (15 MPix - ~4700 X ~3100), and a client has asked for 12000 X 12000 px images for a poster for a trade show exhibit. She wants 300 DPI at 40" X 40" because customers will be seeing the posters up close. The pictures are of a product about the size of your finger, so we're looking at 40-60X life size.

I shoot with strobes in my studio, so renting an LF camera and scanning back is not practical.

What are my options for taking perhaps a 3 image X 4 image matrix and stitching? That would yield an image well over her 144 MPix requirement.

How do I index both vertically and horizontally when taking a high-rez matrix picture?

Or, how can I convince the client that she doesn't really need 144 MPix for a 40in X 40in image?

Thanks,

Click to expand...

1. Jim Collum and Mike Spinak are in your area. Both among one of the smartest and most talented guys I know and Jim happens to own a scanning back! Send them each a PM! If they are free, at least one of them is likely to help you.

2. Borrow/rent a 5DII and a 50 2.4 macro lens with a lifesize multiplier. The camera will give you a 1600x1600 image of your object which can be upressed x7.5 to get 12,000. I just checked it with a picture taken at random from my collection. With just one image, I could go to 12,00x12,000 even in PS 7 with simple bicubic option! Better 2x2, ie 4 stitched images you only have to upres by ~ 2. Set up the camera to swing rotate through the entrance pupil and check for parallax with two pencils one in front of the other in the position of the front and back of the object. As the lens is rotated from side to side, the pencils should stay lined up one in front of the other.

Do you have a stage for that? If not you can rent one near you. Manfrotto or RRS.

Let is know what your timetable is.

Asher

Charles L Webster said:

I shoot with a Canon 50D (15 MPix - ~4700 X ~3100), and a client has asked for 12000 X 12000 px images for a poster for a trade show exhibit. She wants 300 DPI at 40" X 40" because customers will be seeing the posters up close. The pictures are of a product about the size of your finger, so we're looking at 40-60X life size.

I shoot with strobes in my studio, so renting an LF camera and scanning back is not practical.

What are my options for taking perhaps a 3 image X 4 image matrix and stitching? That would yield an image well over her 144 MPix requirement.

How do I index both vertically and horizontally when taking a high-rez matrix picture?

Or, how can I convince the client that she doesn't really need 144 MPix for a 40in X 40in image?

Thanks,

Click to expand...

Your best bet is to ask Nicolas how he does it. He was able to get a +/- 4m x 2.5m print of a boat from a single frame which was very much detailed upon close inspection (I saw it with my own eyes at the Boot Messe in Dusseldorf). See this thread for the pictures of that and also this one for some others.

Charles L Webster said:

I shoot with a Canon 50D (15 MPix - ~4700 X ~3100), and a client has asked for 12000 X 12000 px images for a poster for a trade show exhibit. She wants 300 DPI at 40" X 40" because customers will be seeing the posters up close. The pictures are of a product about the size of your finger, so we're looking at 40-60X life size.

I shoot with strobes in my studio, so renting an LF camera and scanning back is not practical.

What are my options for taking perhaps a 3 image X 4 image matrix and stitching? That would yield an image well over her 144 MPix requirement.

Click to expand...

Hi Chas,

This is a project that's right up my alley. Stitching can definitively give you what's asked for, and more. However, there are a couple of pitfalls. Some more input is needed to compute the specifics.

1. One of the issues may be DOF. The exact size of the object, so including the visible depth from the presumed vantage point, would be helpful. Will there be space surrounding the subject then that will be the width/height to calculate with. Maybe focus stacking is needed for such a small object, because DOF will be shallow.

2. What kind of perspective is preferred? Close-up look, natural look, or seen from a distance. That will determine part of the calculation for focal length and number of tiles.

3. What kind of printing method will be used? On a Durst Lambda style of printer you may need 254 or 400 PPI, on an inkjet 300 or 360 will deliver super photoquality, but 600 or 720 PPI will be even better (unless the subject doesn't have a surface structure that needs it). Depending on the stitching method a certain additional downsampling factor might need to be factored in.

Maybe the PPI requirement can be relaxed a bit because, as Cem pointed out, jaw dropping images can be made from more modest pixel quantities. It depends on the subject matter, material surface, and also on the medium it's printed on. Canvas e.g. can get by with lower PPI, and high contrast subjects also need fewer PPIs because they look sharper already, and may be helped by the right kind of upsampling software.

How do I index both vertically and horizontally when taking a high-rez matrix picture?

Click to expand...

For stitching you need to shoot with some overlap between the image tiles. You'll need to get a good solid 3D panohead which allows to rotate through the entrance pupil of the specific lens for the specific focus distance. With a good panohead that's not too difficult to calibrate.

Or, how can I convince the client that she doesn't really need 144 MPix for a 40in X 40in image?

Click to expand...

By showing a smaller size (e.g. 8x10in) example of a comparable subject taken with a lower PPI. Maybe present a series of (unmarked) prints from the same image but with different PPI sources. Do make sure that the downsampled source images are properly downsampled, otherwise the test may be misleading.

For all images make sure that a good sharpening algorithm is used, something like Focus Magic, and good printer resampling when upsampling is required.

Cheers,
Bart

Hi Charles
Bart has set the right tech points…

A question: is 40"x40" @ 300dpi (roughly 1 square meter @ 300 dpi) the output size?
That is not much!

Some needs:
Best quality lens, prior to # of pixels
The print MUST be done on a Lambda printer (or Lightjet) on analog photographic paper.
Can you rent a 1DsIII?
I made numerous test with the Lambda, I can't beat the RIP forupsizing upper than 125 dpi!

There still exists techs in labs to require 300 dpi output. They just don't know what they're talking about.

So what you need to convince your client (and get yourself confident) print a portion of your file at real size…

Charles L Webster said:

I shoot with a Canon 50D (15 MPix - ~4700 X ~3100), and a client has asked for 12000 X 12000 px images for a poster for a trade show exhibit. She wants 300 DPI at 40" X 40" because customers will be seeing the posters up close. The pictures are of a product about the size of your finger, so we're looking at 40-60X life size.

I shoot with strobes in my studio, so renting an LF camera and scanning back is not practical.

What are my options for taking perhaps a 3 image X 4 image matrix and stitching? That would yield an image well over her 144 MPix requirement.

How do I index both vertically and horizontally when taking a high-rez matrix picture?

Or, how can I convince the client that she doesn't really need 144 MPix for a 40in X 40in image?

Thanks,

Click to expand...

Nicolas Claris said:

Hi Charles
Bart has set the right tech points…

A question: is 40"x40" @ 300dpi (roughly 1 square meter @ 300 dpi) the output size?
That is not much!

Some needs:
Best quality lens, prior to # of pixels
The print MUST be done on a Lambda printer (or Lightjet) on analog photographic paper.
Can you rent a 1DsIII?
I made numerous test with the Lambda, I can't beat the RIP forupsizing upper than 125 dpi!

There still exists techs in labs to require 300 dpi output. They just don't know what they're talking about.

So what you need to convince your client (and get yourself confident) print a portion of your file at real size…

Click to expand...

I think I'll have no control of the final output. My understanding is that the graphic artist prepares the files and hands them off to the exhibit maker, but...

I'm lucky that I can rent pretty much anything here in the Bay Area, so I'm not concerned about equipment availability. I am concerned about client expectations, I don't know that they have ever done this (made big photos) before, so I don't know exactly what quality they'll accept.

I'll look into renting an indexing pano head of some sort and see what can be done, but I fear there will be issues with the fact that the object to be photographed is about 1in (2.5cm) long and 1/2" (1.2cm) in diameter, so tiles will have to be 1/4" (7mm) by 1/4" (7mm).

Thanks Nic, I appreciate your advice and will update everybody as I learn more.

Hi Chas
You're welcome!-)

It is a pretty small object to shoot!

I don't think stitching would make it…

Then if renting is easy, I would go for a MF camera with a P65 back (http://www.phaseone.com/Content/p1digitalbacks/Pplusseries/Introduction/TechSpecs.aspx)
In one shot you should be quite close to what is asked by your client…

Charles L Webster said:

I'll look into renting an indexing pano head of some sort and see what can be done, but I fear there will be issues with the fact that the object to be photographed is about 1in (2.5cm) long and 1/2" (1.2cm) in diameter, so tiles will have to be 1/4" (7mm) by 1/4" (7mm).

Click to expand...

Hi Chas,

If the subject has no dept, you didn't mention, then you could use another technique. You could get an X/Y stage to mount the object on, and leave the camera stationary. The camera would need a serious specialist macro lens (larger than 1:1, e.g. Canon MP-E 65mm), or alternatively a bellows setup with a good (reversed) lens for such close-up work, preferably one that allows to shift the camera instead of the lens. The lens should offer a wide enough image circle for shifting though, so you may need a shorter focal length which might get in the way of lighting the subject.

Also, don't forget that unless the object is printed from edge to edge, the field of view is a bit wider than the subject alone.

Bart

Hi Chas

its doable, while not to easy and time consuming:

I made a while ago a poster for a art museum in the same size (and printed in 300 dpi) as you need from a small detail of a painting, and it worked in 25 x life size. Using a FF cam and the 100 mm macro, reaching 1:1 - the 50 mm macro will not allow to get close enough and make enough tiles for your needs. The panohead and its No Nodal Point - have to be set-up extremely precise to prevent failure when stitching.

In your case, I wouldn't go for native 300 dpi; for that poster I went to about 50 % native - or real pixels, made the RAWdevelopment carefully and uprezed to the meter size. It just looked perfect, even when inspecting it carefully: details than you don't see by eye became visible, like the paper's structure..scratches in the color, etc.

Off course: you will see only the things, the lens can resolve, therefore make sure to use the best one you can find.

I had done Lamda prints of rooms in meter size before with stitches of 3 images only and they worked well: even people will get close to the end image, nobody uses a loupe to test the resolution, a good light and perfect RAWdevelopement is more important than a few Megapixels more.

I'm aware that 30 x lifesize is making it more complex, therefore I' d try to make some tiles, but not to many, as DOF will become very small, when going to close.

BTW: How flat is that object? Maybe, I could suggest a different stiching strategy.

Watch out: make sure you really get a perfect object, as the minorst scratches, etc will be huge later and call for hours in retouching.

Even if you don't go for 300 dpi native, you'll require more than a day for testing, set-up & stitching, I think I had used 12 or 9 tiles for the poster, it took me some hours, even I know stitching since a good while.

If you aren't used to stitching, the apps, etc I suggest MF and a back or LF and a 4/5' -film. Easier, and more comfortable for a non stitcher.

Being from the old guard, I'd simply take as large a view camera as I could find, loaded with slow film, and produce an image with the best prime, (primo!), optic I could lay hand on. Ultra clean processing of the film and retouching any flaws should do the trick.

THEN scan or shoot the resultant image into digital, all the multiple panes you want, if you wish to DIY. I wonder about labs that could directly scan to a large file for you.

I've seen a lot of posters at trade shows, and when a small object is reproduced really huge, the visual impact overshadows a lot of the critical viewing tendencies, anyway. Upsampling a 20+ Mpixel image should really be all that's necessary.

As for the original image itself, I remember seeing a photo of several bellows coupled together for this type of small subject where the idea was to get more depth of field with a longer lens. (Remember the function of the change in reproduction ratio through the depth of your shot, as you ponder those circles of confusion...)

I wonder when there will be a 4" x 5" imaging sensor? Imagine the pixel count!

I will try to obtain details of the digitization of 4x5 transparencies, that a friend once made for a Hollywood project.

Bruce

Bruce
as you brought a old thread at the surface, I wonder what Chas finally did...

Michael Fontana said:

Bruce
as you brought a old thread at the surface, I wonder what Chas finally did...

Click to expand...

Being a newbie, I read the ones of interest, regardless of posting dates. This had no conclusion, so...

It had several solutions, one of which took me back to the days of my own commercial photograpgy company in the early 70's. Yes, some of us are still alive from those days!

Bruce

Results - not so many megapixels needed

They ended up using the magazine layout shot (15 Mpix) to make the poster. The subject, a cutting instrument for operating in the eyeball, ended up being about 20" long and 8-10" wide. The graphic artist responsible for the poster up-rezed the image at her end (I don't know what tools).

The client was pleased with the picture and had no complaints about the quality.

If I had to do this again, I would rent a 39Mpix camera at the local pro shop and be done with it. They require that you purchase a training session before you can rent the camera, so I would not be practicing on client time.

We've since done another poster direct from the 50D files and everyone is pleased with the outcome. The latest poster of a shoebox sized unit, looked good and was well received at the recent American Academy of Ophthalmology conference in San Francisco a couple of weeks ago.