Is this banding?

[Avraham Monina]

I got some macbook pro tops, I etched some random vector art on it (RGB black) and where there is alot (I mean not just line, like a solid circle like the photo) I see this banding looking effect which is no good, I am using 100 speed and 40 power( which is what epilog has for the iphone they etched on the website), is 40 too strong?
Thank you!!

[Scott Shepherd]

Yes, that's banding.

[Avraham Monina]

I was under the impression that banding only happens in images and not in vectors art? I know with photos you need to match the DPI for it not to band, what about vector art?

Yes, that's banding.

[Scott Shepherd]

Nope, not the case at all. It'll happen to anything, bitmap or vector based.

[Chuck Stone]

Color fill is considered raster, correct?

[Dee Gallo]

I have written in my book: MacBook 100sp/35p/1000dpi. I collect settings even if I haven't tried them, so take it for what it's worth. Anyway, it has been shown previously that some banding can be caused by resizing an image after treating it in PhotoShop, but yours does not look like a photo. Is it a bitmap image? Others have changed a filled shape from 100% black to 80-90% black to eliminate banding. Please post your successful settings for future reference!

cheers, dee

[Avraham Monina]

Thanks Dee and Scott, I will post results.
But heres another question, if I try ti use 80-90% black, isent lowering the power or speeding up the speed will cause the same results?

I have written in my book: MacBook 100sp/35p/1000dpi. I collect settings even if I haven't tried them, so take it for what it's worth. Anyway, it has been shown previously that some banding can be caused by resizing an image after treating it in PhotoShop, but yours does not look like a photo. Is it a bitmap image? Others have changed a filled shape from 100% black to 80-90% black to eliminate banding. Please post your successful settings for future reference!

cheers, dee

[Scott Shepherd]

Thanks Dee and Scott, I will post results.
But heres another question, if I try ti use 80-90% black, isent lowering the power or speeding up the speed will cause the same results?

No, not at all. By changing the color to 90% black (which is not what I'd suggest in this case), it'll create dots further apart on your graphic. So the edges will be a little jagged, instead of pretty smooth. If you reduce the power or speed up the speed at 100% black, you still have full coverage of the dots. Two totally different things.

I can't speak for your machine but banding can be a bear to get rid of. Sometimes going very slow works, taking it out of focus some helps too. Maybe focus .030" above the work, run it at 40% speed (don't know what power to recommend for you). All these things can help.

[Avraham Monina]

I understand, thank you!

[Yuriy Karpov]

I've found that some coated materials have banding effect, sometimes it helps to lower the power for about 20-30%. It might be just uneven coating.

[Avraham Monina]

So, after much trial and error I finally got decent etching with very very minimal banding, Check out the first photo, I intentionally made it darker in photoshop so you can see the banding better, I tried different speed and power settings, then I changed the color from totally black to grayish and got better results BUT I started to notice that there are spaces between the dots (see 2nd photo), 2nd photo is a super close up (like 300%) but I can see the difference with the naked eye and I imagine that once you do etching that you dont have the other to compare to you would not notice the difference.
I used the RGB gray #666666 Power - 40 Speed - 100, autofocus ( I did try to lower the bed a bit but did not see a difference as banding was still very visible)
Thank you all for your help, I am open to other suggestions from anyone.

[Scott Shepherd]

I think 100 power is WAYYYYYYYY too much power. Try 40 speed, 15-20 power and work from there. 40 speed with 100 power is very hot, way more than you need for this, I think.

[Avraham Monina]

Scott, I might have wrote it wrong, but I used 100speed not power, I used 40 power

I think 100 power is WAYYYYYYYY too much power. Try 40 speed, 15-20 power and work from there. 40 speed with 100 power is very hot, way more than you need for this, I think.

[Kees Soeters]

Hi Avraham
Can you make the first picture so that you write your settings in each part so we have an overview where some setting lead to?
I also did some tests on glass and noticed quite a difference in powersettings and speed.. Every matarial will have his own settings however..
I also noticed that vertical banding has to do something with power.... could this be a instability in the HV-supply?? Can we tune the HV-supplies with a larger capacitor for instance? or take a supply that's intended for a tube with more power (60W tube with a 80w supply for instance)???
who??

Kees

[Avraham Monina]

IMG_0662EDITED.jpg

Im sorry I dont remember all of them, but I wrote down as much as I can.

Hi Avraham
Can you make the first picture so that you write your settings in each part so we have an overview where some setting lead to?
I also did some tests on glass and noticed quite a difference in powersettings and speed.. Every matarial will have his own settings however..
I also noticed that vertical banding has to do something with power.... could this be a instability in the HV-supply?? Can we tune the HV-supplies with a larger capacitor for instance? or take a supply that's intended for a tube with more power (60W tube with a 80w supply for instance)???
who??

Kees