Help with laser and image

So I’ve been working on getting better results from my Jtech 2.8W laser and PicEngraver Pro5. I have tried a couple images and I think I need a better method of accessing how the laser burns grey scale on my surface.

Here is an example of a Fallout 4 image that I tried to burn, the dark values are good, but there was a lot of high lights that seem to be left off. I have included the image I used (I did lighten it a bit to try and get the lighter values to pop, not seen here) plus the result.

I used 90ipm, min 0, max 255, pixel size .006, 45 deg processing

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A big issue is burning on to MDF. I found that when you are trying to do a grey scale image MDF sucks. It burns too easy. I started using poplar as a test wood. The other thing I am seeing is the lines in the MDF. Are you using the lens that came with the laser? Have you had good results burning grey scale on anything else? I never could get the stock J Tech lens to focus to my satisfaction. I ended up replacing the lens with one that focuses in to a circle rather than an oval and now it works fantastically.

Default JTech lens focused as per instructions at 3". I have not tried other wood, but did notice that the MDF did burn rather fast and wondered if that was the issue. I’ll try just some plain grey scales tonight to see what I get on different woods.

Where did you get your replacement lens?

MDF is probably your biggest issue. I can see from the images that it tried to burn in grey scale. Basically with MDF you get untouched or black as coal, with little in between. If you still aren’t happy with the results on other wood I got the lens off ebay. It’s cheap but coming from China it took 25 days to get stateside for me so you may wait a while. This is the one I got and the credit for this gem goes to @picengravertoo

http://www.ebay.com/itm/445nm-Glass-Collimating-Lens-M9P0-5-Metal-Frame/261157555202?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D38530%26meid%3D82869cdc60364dcba0b6004c8d168579%26pid%3D100005%26rk%3D3%26rkt%3D6%26sd%3D262123899104

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Will this lens just screw in where the existing lens attaches? Drop in replacement?

Sure is. It just doesn’t have the fancy silver thumbscrew piece and the focal point is different. It must be focused at 3 inches and you will want to use hot glue or something similar to hold it in as when focused correctly it has little thread contact.

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Tried some 1/8" ply form the hobby shop that I had laying around also got some poplar form the HD.

I ran a couple of the 60 grey square images at different speeds to see how it did. I ran one at 75 in/m and one at 55 in/m the later seemed to do better. So I ran the new Fallout T60 image:

Getting better!!! I’m thinking maybe I could have gone a bit faster and still held the detail. Will try again tomorrow and on Poplar this time.

I placed the order for that lens as well, can’t hurt.

Thanks - Jer

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I usually run about 70 ipm on poplar with a 25% feed rate change.

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