producing an image 12x27meters @120dpi

[klausesser]

producing an image 12x27meters @120dpi

by klausesser » Mon Oct 09, 2017 5:20 pm

Hi!

In my series of extremely high resolution for artists i produced the data for an image of 12 meters x 27meters to be printed @120DPI - which is absolutely unusual (usually those big prints get printed with 15-20 DPI because of the usually very long viewing-distance with images of this kind of size.

But in this case - for some resaons - the resolution needed to achieving perfectly sharpness and high resolution to make it possible to view it close to ONE meter in perfect sharpness without ANY digital artifact like Pixels or noise.

Here´s the image mounted on the house-front of an embassy in Berlin, next to the Holocaust Memorial:
http://www.klausesser.de/TerrAdl.jpg

I used THIS setup -
Head: Panoneed,
Controller: T & C Touch-Control
Camera: Nikon D800
Lens: Nikon AF-S 300mm 1:2,8 II G VR
Tripod: Gitzo

The zoomable version of the print-data:
http://klausesser.de/Awe_interaktiv/index.html
(zoom in deep)

Print-/Datafile RGB: 24 Gigabyte.

Klaus

[Destiny]

Re: producing an image 12x27meters @120dpi

by Destiny » Mon Oct 09, 2017 11:34 pm

Are you sure about this.. "prints get printed with 15-20 DPI" Have you ever printed anything at 20dpi..?? You would be able to see the pixels..

Image attached is 20dpi. Printed it would be worse and unusable.. I would like to learn more about this.. You are the expert in this area....

Destiny...

Attachments

[signmaster]

Re: producing an image 12x27meters @120dpi

by signmaster » Tue Oct 10, 2017 12:11 am

I have a Sign Writing business and very large prints are often printed using 20 DPI files but the actual printer will print at 360 DPI, the file is up-rezed by a RIP program. All depends on the viewing distance and the size of the sign. We have 2 large format printers that print up 1600mm wide (We do much larger signs in panels.) The lowest resolution that it will print at is 540 x 360 dpi. Normally the lowest resolution file I send to it would be about 70 dpi but normally 100 dpi and above, very hard to tell the difference between 150 dpi and 300 dpi. The 20 dpi files would be sent to much larger printers than mine and for very large signs viewed at a distance, this is more to do with keeping the file size controllable than any thing else. Most of our work is with vector files so the resolution will depend on what I set the printer to print at. The highest I can print at is 720 x 1440 dpi.

Klaus, an excellent job on that artwork. I have done a few artwork jobs and normally photograph the original art in my studio using Color Checker Passport and lIghtroom/Photoshop for processing. Completed a job a little time back of 6 original art pices at 700mm x 700mm and printed at about 2400 x 2400mm. Used a 5D Mk III, the artist was very happy with the final result.

Steve

[Destiny]

Re: producing an image 12x27meters @120dpi

by Destiny » Tue Oct 10, 2017 12:23 am

Hi Steve. Thank you for clarifying that. I do not do print commercially, only at home from my home printer at 20 dpi, or ppi, the quality would be terrible.. But, if I printed a Vector image the quality is excellent.. Pixels do not count when it comes to Vector since there are none in reality, only bitmaps have actual pixels in their makeup... My printer will print up to 300dpi... I do understand that software can print smaller dpi at higher res.. But I did not know that they could produce a high res from just 15 or 20 dpi image... I guess the file size would be heaps smaller... and you could send via the web...

Destiny...

[signmaster]

Re: producing an image 12x27meters @120dpi

by signmaster » Tue Oct 10, 2017 12:37 am

Not High rez at 20 dpi but still looks good at a distance. Only talking about very large prints and the up-rezing of the RIP and printer helps things a lot, still will look bad at a meter or so away.

Steve

[Destiny]

Re: producing an image 12x27meters @120dpi

by Destiny » Tue Oct 10, 2017 12:46 am

I thought it might.. Last year we wanted to print some A1 sheets of paper to make up a large backdrop scene for the students Christmas play.. I created most of the graphics using Vector and saved the images as a EPS, to keep the Vector format for print.. It worked out very well.. But a Photo, you cannot use Vector, so it has to be a Bitmap, probably a TIF or perhaps a PDF, not sure, in order to get the better quality.. I am not really a print person but this is very interesting..

However, in saying you cannot print a photo in Vector is not quite true since there is software that can convert a Bitmap to a Vector.. This means you can stretch the images out to a huge image without it pixelising. Not perfectly accurate but the software is getting better..

Destiny..

[signmaster]

Re: producing an image 12x27meters @120dpi

by signmaster » Tue Oct 10, 2017 12:53 am

Converting complex files to vector is very hard and often produces files that are quite large with lots of nodes. We use Corel Draw, Signlab and Adobe Illustrator and they all crash and have trouble with complex vector files. Also our laser engravers and RIP have problems with complex vector files. Technology in that area has a long way to go.

Steve

[Destiny]

Re: producing an image 12x27meters @120dpi

by Destiny » Tue Oct 10, 2017 1:30 am

True...

D...

Technology in that area has a long way to go.

Steve

[klausesser]

Re: producing an image 12x27meters @120dpi

by klausesser » Tue Oct 10, 2017 11:54 am

Are you sure about this.. "prints get printed with 15-20 DPI" Have you ever printed anything at 20dpi..?? You would be able to see the pixels..

Image attached is 20dpi. Printed it would be worse and unusable.. I would like to learn more about this.. You are the expert in this area....

Destiny...

Destiny - i see you´re not into this, so please let me explain.

Viewing a print relates to the distance, from which you look at it. Viewing a print from nearby means to need a
print-resolution (DPI) which lets you see the print without showing any artifacts like pixels or dots for example.

The 300DPI standard comes from the viewing-distance on arm´s lenghts (as a rule of thumb).
So ideally your print should have this reolution - and so should the image data.

Big prints - like advertising posters in the streets - usually get printed with 90 or 120DPI.

VERY big prints - like the one i showed on the front of the embassy - usually are viewed on distances of some
dozens to some hundred meters.

For THIS distances a print-resolution of around 20-40 DPI is WAYS enough: our eyes can not differenciate the single dots but see a fine picture.

The closer you come to this print, the more "dots" ("DPI" - "Dots Per Inch") you will see.

In the cases i´m working on these very big prints get mounted on a way the viewers can come close to 1 or 2 meters to the print - like in THIS situation: http://www.klausesser.de/En_Vie/index.html

Because of the sharpness of the artist´s work he demanded to realize, to "feel" his intention on a far distance as well as from rather close.

So we decided to shoot extremely highres to be sure both ways to view the works can be done in an almost perfect presentation.

This way to work is absolutely unusable - and to produce the data for this prints also needs to happen in an absolutely
unusable way . . . which also means very high costs.

The image you see on the building later was used on street level and the viewing distances were from about 50meters to
about 2 meters.

Seen from 2 meters´s dístance it looked perfectly the same as seen from 50 or 100 meters - not artifacts, tack-sharp.

http://www.northlight-images.co.uk/what ... -distance/

best, Klaus

[klausesser]

Re: producing an image 12x27meters @120dpi

by klausesser » Tue Oct 10, 2017 11:58 am

Pixels do not count when it comes to Vector since there are none in reality, only bitmaps have actual pixels in their makeup...

Right - but when you bring them on paper the DOTS count. ;-)

It´s alwas relevant to regard the duality of "pixels" and "dots".

Klaus

[klausesser]

Re: producing an image 12x27meters @120dpi

by klausesser » Tue Oct 10, 2017 12:03 pm

But I did not know that they could produce a high res from just 15 or 20 dpi image... I guess the file size would be heaps smaller... and you could send via the web...

They CAN NOT "produce a "high res" from just 15 or 20 dpi image - the SIZE of the print is what counts here.

I mean, 12 x 27meters and 6 x 32 meters means something, does is . . . .

Klaus

[klausesser]

Re: producing an image 12x27meters @120dpi

by klausesser » Tue Oct 10, 2017 12:09 pm

Converting complex files to vector is very hard

It´s impossible with fine image-data.

and often produces files that are quite large with lots of nodes. We use Corel Draw, Signlab and Adobe Illustrator and they all crash and have trouble with complex vector files. Also our laser engravers and RIP have problems with complex vector files. Technology in that area has a long way to go.
Steve

Vectors basically were not invented for conversion into photographic image data

Klaus

[klausesser]

Re: producing an image 12x27meters @120dpi

by klausesser » Tue Oct 10, 2017 12:23 pm

probably a TIF or perhaps a PDF, not sure, in order to get the better quality..

PDF might contain JPG or TIFF images - depends on the way you save it.

However, in saying you cannot print a photo in Vector is not quite true since there is software that can convert a Bitmap to a Vector..

No. You can convert BITMAP - but that doesn´t necessarily mean a photograph! Graphical data can also come
as bitmap - and THIS you can convert to vectors. But no photographs - aside from wish to having them heavily distorted.

This means you can stretch the images out to a huge image without it pixelising. Not perfectly accurate but the software is getting better..

If you mean "Perfect Resize" or other image-resizers - that´s a ver different cup of tea! ;-)

Klaus

[Destiny]

Re: producing an image 12x27meters @120dpi

by Destiny » Tue Oct 10, 2017 12:43 pm

I am only interested in this post since last year we tried to get a large scene printed for the kids Christmas play.. It was hard to get done and expensive. We split the image up into A1 pages which was the larges the print shop could print for us on a budget.. We stuck the images on a large plywood board.. From a distance it looked Ok, but close up it was not so good.. Its always nice to gain some more knowledge in this for my own use... I am not really into print much...

Thank you for explaining it...

Destiny..

[klausesser]

Re: producing an image 12x27meters @120dpi

by klausesser » Tue Oct 10, 2017 1:20 pm

From a distance it looked Ok, but close up it was not so good..

Bingo!! That´s exactly what it´s all about with printing

Thank you for explaining it...
Destiny..

You´re welcome!

best, Klaus

[klausesser]

Re: producing an image 12x27meters @120dpi

by klausesser » Tue Oct 10, 2017 1:26 pm

You are the expert in this area....

Oh no - i´m an expert in shooting hires and producing the data. But i have assistance from
some prepress-experts. They´re the real cracks when it comes to highend-printig.

best, Klaus

[klausesser]

Re: producing an image 12x27meters @120dpi

by klausesser » Tue Oct 10, 2017 1:50 pm

We split the image up into A1 pages which was the larges the print shop could print for us on a budget.. We stuck the images on a large plywood board..

I failed to mention in my other reply:
The same happens when extremely large prints are made: the image-data file gets stripped into colums in a width
the printers can print on.

Each row gets printed with the maximal resolution the RIPS can handle. In the end all the rows are mounted to ONE giant print.

Klaus