Why does my old HP 6L print images better than my newer HP laserjets?

[smeelah]

I have also been confused by the Ginkgo Test image. Copying and printing it from post #6 produces a 20mm x 20mm print, but opening the image in a new tab and copying it produces a 15 cm x 15 cm print, so the image in post #6 is a thumbnail I think.

A 300 dpi scan of the thumbnail print made by the HP Laserjet 1018 looks very similar to the right hand print of post #1:

View attachment 14229

Hi Peter,
I'm wondering if you ever got a good print with the 1018?
thanks!

 

[PeterBJ]

I have only had the results I have already posted. If the HP Laserjet produces a good print I will let you decide.

I wondered about the coarse raster produced by the Laserjet 1018 and the old inkjet printer HP Deskjet 930. I printed a test image containing a greyscale with the laser printer. I examined it with a USB microscope at 50 times magnification and compared it to a millimetre paper printed on the Canon MP980. Here is a 5mm x 5mm crop of the millimetre paper print, click to enlarge:



And here is a 5mm x 5mm crop of a field of the greyscale, click to enlarge:



Counting the dots you get 15 dots per 5mm or approximately 76 dots per inch??

But maybe resolution in dpi is not the same as counted dots per inch in the printed raster?

Maybe someone who knows more about this subject could explain?

 

[Printguy]

Hi!
I've always used an HP 6L to print small detailed images for my jewellery design business. I've been having new issues with the printer and so I've started trying to find a replacement. Both my HP 1018 and HP MFP M28w print fine except that with images, you can see the dots. The images are not smooth. Increasing the resolution has not helped. I've tested different drivers, different settings, different apps. I'm using Mac OS 10.12 at the moment.

I would appreciate any help or a point in the right direction.
Thanks,
Leila
View attachment 14194

Your HP 6L appears to be printing halftones using the Floyd-Steinberg dithering algorithm (https://en.wikipedia.org/wiki/Floyd–Steinberg_dithering), which is arguably the best one for the job. HP M28w, however, uses a generic dotted halftones pattern. The difference is caused by the printer drivers, actually, not the printers themselves.

It is worth noting that both printers are capable of printing the images identically, if you do the pre-processing yourself in Photoshop by following these steps:

1) Convert the image to grayscale
2) Resample the image to use the target image size and native printer resolution (such as 600 dpi)
3) Convert the image to black-and-white, using the appropriate dithering algorithm
4) Print without scaling, at 100%

 

[smeelah]

Your HP 6L prints halftones using so called Floyd dithering, which is, arguably, the best dithering algorithm. HP M28w, on the other hand uses generic dot-bases halftoning


Your HP 6L appears to be printing halftones using the Floyd-Steinberg dithering algorithm (https://en.wikipedia.org/wiki/Floyd–Steinberg_dithering), which is arguably the best one for the job. HP M28w, however, uses a generic dotted halftones pattern. The difference is causes by the printer drivers, actually, not the printers themselves.

It is worth noting that both printers are capable of printing the images identically, if you do the pre-processing yourself in Photoshop by following these steps:

1) Convert the image to grayscale
2) Resample the image to use the target image size and native printer resolution (such as 600 dpi)
3) Convert the image to black-and-white, using the appropriate dithering algorithm
4) Print without scaling, at 100%

This is amazing information. Thank you. Is it possible to add a dithering algorithm to photoshop or do I need to work the with the options available?

 

[Printguy]

This is amazing information. Thank you. Is it possible to add a dithering algorithm to photoshop or do I need to work the with the options available?

Yes, it is possible. "Diffusion Dither" is the Floyd-Steinberg one. There are 3 other built-in methods, or you can create a custom one:

 

[SkedAddled]

I'll agree with the halftone assessment, as well as dithering.

In the infancy of printers becoming common in businesses, then consumer-grade,
it was common for printers to use halftoning and dithering heavily.
This put a more realistic image to the paper as desired by most users.
It made for a better film-photographic representation than a digital graphic.

A good example was my old HP LaserJet 6.
A monochrome printer, it produced very good quality B+W images on plain paper.
Later monochrome printers began printing less of the dithering and grayscaling,
with dots of old newsprint becoming apparent.

As time has gone on and digital images have become more detailed,
so has the printer industry been moving away from the smoothing
technologies they used to so heavily feature.

Nowadays, I wouldn't expect to find halftone and/or ditering options available for
most laser printers or ink printers, although I'd suspect they have been rolled into
similar functions which have been renamed. More likely, I'd expect such options
to be coming from a program/app generating a print, and not from a printer
driver itself.

I use an ancient version of Paint Shop Pro(7.x) and Photoshop CS6.
The differences in print output from each are very different on modern printers,
which seems to support an app-level driver as opposed to device-level drivers
beginning from about the era of Windows 98.

 

[Smile]

Well the answer can be many started to print money so to make it hard manufacturers of laser printers are now making printers with crap quality when printing images. Do not believe me? Then explain bad ratings in graphics/photo for the best laser color printers on rtings website.

 

[smeelah]

I'll agree with the halftone assessment, as well as dithering.

In the infancy of printers becoming common in businesses, then consumer-grade,
it was common for printers to use halftoning and dithering heavily.
This put a more realistic image to the paper as desired by most users.
It made for a better film-photographic representation than a digital graphic.

A good example was my old HP LaserJet 6.
A monochrome printer, it produced very good quality B+W images on plain paper.
Later monochrome printers began printing less of the dithering and grayscaling,
with dots of old newsprint becoming apparent.

As time has gone on and digital images have become more detailed,
so has the printer industry been moving away from the smoothing
technologies they used to so heavily feature.

Nowadays, I wouldn't expect to find halftone and/or ditering options available for
most laser printers or ink printers, although I'd suspect they have been rolled into
similar functions which have been renamed. More likely, I'd expect such options
to be coming from a program/app generating a print, and not from a printer
driver itself.

I use an ancient version of Paint Shop Pro(7.x) and Photoshop CS6.
The differences in print output from each are very different on modern printers,
which seems to support an app-level driver as opposed to device-level drivers
beginning from about the era of Windows 98.

Interesting! I am beginning to understand that it's not so much about capability but what the manufacturer choses to include...based on the main category of consumers. For instance, I tried to find an inkjet that ticked all my boxes but some of the attributes were only on 'home business' printers and some were only included in the 'home artist' printers.

I am also using and old Photoshop (CS5).

 

[smeelah]

I picked up an HP 2100. Amazing prints on a macro level. Lots of output options. Unfortunately, I need a printer that will not only print sharp macro graphics but also uses toner with a high iron oxide level. Surprisingly my HP MFP M28w has iron levels (or some other metal oxide?) equal or higher than my HP 6L but the 2100 does not - I even tried two different micr toners.