You are reading Neal Stephenson upside down!
Definitely a finer grind on the right, though.
Neil
You are reading Neal Stephenson upside down!
Definitely a finer grind on the right, though.
Neil
And if you use Alum Oxide, it would look even better. I have a post somewhere that where I learned to just start with the .0002 Alum Oxide, and that's all you need. It makes a finer screen, with no divots.
Garrett
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I agree with Garrett.
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
Okay. I still have not found .0002 aluminum oxide. Is this what I am looking for? https://www.willbell.com/ShoppingCar...M_Supplies.htm
It should be fine. I use this: #591-021 at http://www.lortone.com/abrasives_polish.html
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
I have heard that finer grinds reduce graininess, but also decrease brightness and increase apparent fall-off, but I haven't seen any disadvantage to the finer abrasives yet.
If I can find them I will try installing the cheap page magnifier fresnels I bought too.
Science is what we understand well enough to explain to a computer. Art is everything else we do.
--A=B by Petkovšek et. al.
Ok, I eat Crow again! Tasty.
I made an 11x14 GG last night using Garrett's way and used 3 micron aluminum oxide that Peter gave me. One step on Home Depot framing glass. Then I held it up next to my 2 year old 11x14 DIY GG on the same glass, but made with 2 steps of 320 then 500. !!!! I need a way to test this. I don't 'see' a huge difference, but I was tired late last night with bad light.
Both methods took about the same time, One movie. So Garrett is correct that one step with the finest, which is darn fine, like soft mud, is all that is needed.
This chart is handy. http://stellafane.org/tm/atm/mirror-...20Size%20Table
So I propose using 51 USAF target under good light in a dark room, interchange the GG, take a look see and take spot meter readings.
Any better suggestions for testing and comparing GG?
Scratching my fingernail across both felt very similar. Too similar!
Tin Can
Did you use a loupe, and, if so, what power?
“You often feel tired, not because you've done too much, but because you've done too little of what sparks a light in you.”
― Alexander Den Heijer, Nothing You Don't Already Know
First is 2 step 320-500 grit. Second is one step 3 Micron. Second is one stop brighter as measured by Sekonic spot meter.
Ipod shots of 11X14 GG of USAF '51 at 1 to 1 with 10X loupe focus of Nikkor 610mm at f22. Unfortunately the flash fired and made both exposures the same. I am not redoing it. Check exif and notice flash off glass.
I prefer the new finer 3 micron grind.
GG by moe.randy, on Flickr Untitled by moe.randy, on Flickr
Tin Can
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