I was just wondering about the edge case, literally. If you have a rounded brushed metal part (eg a valve-stem), that surface will appear very white and appear to fade smoothly into the white background. That would cause jaggy and ill-defined boundaries when attempting the cutout. Of course one could/should use the pen tool to define the path, but the CS5 "refine edge" tool is just so incredibly nice for that.
On Tue, Jan 24, 2012 at 8:55 PM, David Parsons <parsons.da...@gmail.com> wrote: > If he's doing cutouts, there's no point in using green. White will > work fine, and it won't introduce any color casts that need to be > fixed later. > > On Tue, Jan 24, 2012 at 7:27 PM, Bruce Walker <bruce.wal...@gmail.com> wrote: >> You could do all that fiddling and tweaking, or, since this is a >> budgeted project, you could spring for an incident light meter. >> (Sekonic L-308S: $199 at B&H) >> >> 1. place lightmeter on table and arm it. >> 2. fire flash(es). >> 3. read meter and set camera accordingly. >> 4. take one perfectly exposed shot. >> 5. swap subject part for another part ... go to step 4. >> >> If you alter the lighting, go to step 1. >> >> Now with all the time you've saved, take more shots of more subjects, >> or savour a coffee. >> >> >> Since you are doing cutouts, you might consider using green screen >> techniques. Either paint your background with green chroma-key paint >> (eg Rosco 5711) or just get a roll of green screen background. >> >> You'd have to make sure that none of the green reflects back onto your >> subjects, so this idea may not work well for you. >> >> >> On Tue, Jan 24, 2012 at 5:58 PM, Larry Colen <l...@red4est.com> wrote: >>> >>> >>> On 1/24/2012 1:48 PM, Collin Brendemuehl wrote: >>>>> >>>>> Believe me, as someone who has magic-wanded out more backgrounds that >>>>> I care to admit... it works really well SOME of the time. Other times >>>>> you a messing around with the magic wand sensitivity setting to keep >>>>> it from grabbing portions of your object. >>>>> >>>>> Bruce is correct. Your images are seriously underexposed. The light >>>>> table should be white. It's the same principle as shooting something >>>>> on a snow bank. The meter will make the snowbank 18% grey and >>>>> underexpose the subject. That's what you've got here. You'll save a >>>>> lot of work in post if you expose correctly. Either get off automatic >>>>> to manual or use exposure compensation. >>>>> >>>>> Also, if you have photoshop you may find that working with levels or >>>>> curves (to define your "white") will save you a lot of time with the >>>>> magic wand. Trust me, you don't want to rely on the magic wand. >>>>> >>>>> Darren Addy >>>>> Kearney, Nebraska >>>> >>>> >>>> >>>> I am shooting in Manual mode. >>>> Yes, the Magic Wand has been useful. So many circular objects are more >>>> easily cut with the oval selection tool. >>>> >>>> As to the exposure, I only saw that on a couple of shots, obvious on the >>>> #3 with the PL. I took it off and have not put it back on. >>>> >>>> Shots #1& #2, once separated from the background (about 10 seconds of >>>> work) displays the detail perfectly for the customer's application. The >>>> sense of being underexposed went away with the image on a different >>>> background -- pure white. >>>> >>>> >>>> The paper should not be all white, but perhaps white-er than it is. I >>>> will be adding some reflectors in the next day. Still, the boss is more >>>> than happy with the results achieved. >>>> >>>> Tomorrow I will put up one of the better, later pics with improved >>>> exposure. >>> >>> >>> Since you are shooting in manual mode (and I presume RAW), until you get the >>> system dialed in, why not try some shots where you keep cranking up the >>> exposure? >>> >>> I would suggest two variations on "expose to the right": >>> >>> 1) simply looking at the histogram, this will probably put the table just >>> under clipping. >>> >>> 2) Expose to the right based on the object and let the table clip. >>> The histogram should be bi-modal. There should be a peak for the table, and >>> one for the object. When you expose to the right, ignore the the bump for >>> the table and just keep increasing your exposure until the object itself is >>> exposed to the right. >>> >>> This, of course, has issues if there are sections of your object that are >>> close in albedo to that of the table. The alternative would be to put your >>> subject on a dark background, do your test shots to expose to the right and >>> set your exposure, then remove the dark background, and let the exposure of >>> the table fall where it may. >>> >>> I do hope that you are keeping a notebook with good notes on your different >>> lighting setups. Once you get things dialed in, you should have some base >>> settings that are very close to perfect, and will probably be good enough >>> for most of your subjects. >> >> -- >> -bmw >> >> -- >> PDML Pentax-Discuss Mail List >> PDML@pdml.net >> http://pdml.net/mailman/listinfo/pdml_pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and >> follow the directions. > > > > -- > David Parsons Photography > http://www.davidparsonsphoto.com > > Aloha Photographer Photoblog > http://alohaphotog.blogspot.com/ > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- -bmw -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
