Topic: Taking uranium glass photos - help please!

[KevinH]

As Juli has said, it is possible to "Flood Fill" a background as long as the main object has an outline that does not contain the same colour as the original background. Even a pixel or two identical to the background will result in a "flood fill" causing "flea bites" at best and complete disaster at worst. Also that method only works if there is only one background colour or there are are clear blocks of differing colour.

I rarely obtain a picture with a single colour background - even when using a seemingly white surface! Too much dust and stuff around, not to mention all the subtle colour differences in paper and materials.

So the answer is (again as Juli has suggested) to use editing software that has a "Marquee" or "Lasso" or "Magic Wand" type of tool. This allows you to select the outline of the subject and then use "copy & paste" to crop it and place it in a new image layer, which has its backround colour preset or "flood filled" prior to the pasting.

Personally, I have never found "Lasso" or "Magic Wand" (both semi-automated processes) to be good for anything with varied detail in the subject edges. I tend to rely on free-hand use of the tool often known as "Polygon" or "Polygon Lasso", which is a bit like sewing an edge around the subject ... click for start point, move cursor a few pixels along the edge, click for position, move cursor , click, etc., then a last click to join up at the beginning. The process is either relaxing or irritating, depending on personal mood of the day. But it can be very annoying when you get almost to the end and then click in the wrong place or make a double-click, especially having already made several failed attempts.

[mrvaselineglass]

The best background you can use for blacklight UV photos is black velvet.  I learned this from the photographer that did the photos for my book on vaseline glass.  Yes, for decent pictures, you have to have a tripod and be able to set your camera on a manual setting.  TURN OFF THE FLASH! 

When you do a manual setting, the camera will continue to take in light until it reaches the manual setting you have put on the controls.  This will keep the shutter open for several seconds.  That is why the tripod is essential.  (they are not that expensive....find a used one?)

If you are not using a long fluorescent bulb, and are using a torch instead ("flashlight for the USA readers!  LOL), try wobbling the light around a little bit, it spreads the glow and gives a more 'even' result so you don't have hot spots.  This will not work if you don't have a tripod, because moving the torch with one hand and trying to hold the camera absolutely still on a timed exposure with the other hand is impossible.

Buyers on ebay are only concerned that it does glow a bright neon green.  They don't care if it is in focus.  It is best to put the 'normal daylight' photo as your main thumbnail photo on your ebay auction, then have a blacklight photo as one of the other photos available for viewing.  One of my absolute pet peeves is when a seller takes only one photo and it is a UV  blacklight photo.  If I am going to bid, I have to know that the glass I am buying is yellow in normal room light.  Green uranium glass, yellow uranium glass, burmese glass, custard glass....all contain uranium, and all look a bright green if only one photo is shown.

The black velvet also works very well for taking the 'non-UV' photo.  Here are some photos I have taken using these methods:
(click on any little picture to see the UV photo next to the regular photo)

http://www.vaselineglass.org/blacklight.html

When you are doing the manual setting, try different settings that let the light in faster and slower.  I usually take a range of 3 or 4 photos until I get just the right combination.  There are a lot of times I will take upwards of 20 photos, just to get the perfect exposure.  Even with a tripod, the slightest movement when depressing the shutter (or releasing the finger after pushing the shutter) can cause a slight blur. 

Regards
Mr. Vaseline Glass