Photographing Crystal

mercphoto

This seems a bit hard for the AF to deal with. I built a white box for these shots, and I'm wondering if the auto-focus is not the way to go. Seems a bit soft on me (not that the edges in the glass are super-sharp to begin with).

I have a session on Thursday shooting blown glass. Most of it will have color, which should make things easier.

Comments? Suggestions? Thanks.
Bill

pathfinder

mercphoto wrote:

This seems a bit hard for the AF to deal with. I built a white box for these shots, and I'm wondering if the auto-focus is not the way to go. Seems a bit soft on me (not that the edges in the glass are super-sharp to begin with).

Comments? Suggestions? Thanks.
Bill

Try shooting it both ways - with AF and with manual focusing. Let the image tell you which is best . This is being shot from a tripod is it not?

mercphoto

Shooting crystal

pathfinder wrote:

Try shooting it both ways - with AF and with manual focusing. Let the image tell you which is best . This is being shot from a tripod is it not?

No, handheld. Was outside, so tons of light. That shot was ISO 100, f/8 and 1/1000. I shot again at f/16 and 1/250 to much better results (in terms of focus, sharpness). Didn't see much difference between auto and manual focus when I stepped down the opening. Might try even smaller A, using both IS and tripod.

Lens used was the Canon 28-135 IS/USM. IS was off.

cmr164

mercphoto wrote:

No, handheld. Was outside, so tons of light. That shot was ISO 100, f/8 and 1/1000. I shot again at f/16 and 1/250 to much better results (in terms of focus, sharpness). Didn't see much difference between auto and manual focus when I stepped down the opening. Might try even smaller A, using both IS and tripod.

Lens used was the Canon 28-135 IS/USM. IS was off.

Try a blue velvet surface and background with direct but off axis white light. I have had good luck with crystal and AF but manual focus seems to be the way to go. (just my suggestion...)

Shay Stephens

mercphoto wrote:

Comments? Suggestions? Thanks.
Bill

The photo is overexposed and lacks contrast. Lowering the exposure would help a lot here to bring back some contrast as well as adjusting the levels. You could sharpen it too with unsharp mask in Photoshop. Here is a simulation of what it could look like:



This of course is not the only way to display the piece, but I think it is a good start.

fish

cmr164 wrote:

Try a blue velvet surface and background with direct but off axis white light. I have had good luck with crystal and AF but manual focus seems to be the way to go. (just my suggestion...)

Actually, there are lots of different colors you can use...but stay away from metalics (gold, silver) and white. Crystals (including diamonds) are mostly white, except for what they reflect of the visible spectrum. What you want to do is take the background out of the equation and focus on putting light on it that reflects out. I took some diamond shots awhile back (film) but can't find them to scan

Velvet is a pain in the ass...it shows every little bit of lint and cat fur. Use a polyester knit that doesn't "velcro" crap to it.

So. No fluorescent lights...only incandescent. If you really want it to sparkle, use direct sunlight. No kidding. It's amazing, but it also presents it's own exposure challenges.

as you were.

lynnma

fish wrote:

Actually, there are lots of different colors you can use...but stay away from metalics (gold, silver) and white. Crystals (including diamonds) are mostly white, except for what they reflect of the visible spectrum. What you want to do is take the background out of the equation and focus on putting light on it that reflects out. I took some diamond shots awhile back (film) but can't find them to scan

Velvet is a pain in the ass...it shows every little bit of lint and cat fur. Use a polyester knit that doesn't "velcro" crap to it.

So. No fluorescent lights...only incandescent. If you really want it to sparkle, use direct sunlight. No kidding. It's amazing, but it also presents it's own exposure challenges.

as you were.

Fish!!! Ive missed you.. where the hell have you been???

pathfinder

Shay Stephens wrote:

The photo is overexposed and lacks contrast. Lowering the exposure would help a lot here to bring back some contrast as well as adjusting the levels. You could sharpen it too with unsharp mask in Photoshop. Here is a simulation of what it could look like:



This of course is not the only way to display the piece, but I think it is a good start.

Some glassware looks very nice if the illumination comes from beneath the glass also.....

Shay Stephens

pathfinder wrote:

Some glassware looks very nice if the illumination comes from beneath the glass also.....

Yes I agree:



That is a mix between top and bottom lighting.

mercphoto

Thanks

Shay Stephens wrote:

The photo is overexposed and lacks contrast. Lowering the exposure would help a lot here to bring back some contrast as well as adjusting the levels. You could sharpen it too with unsharp mask in Photoshop.

Thanks! Actually your version of the image has more detail than it did in real life. In other words, in the bright sun, looking through the view finder at the object itself, it was rather washed out and in too much light. I might purposefully under-expose the images as I take them.

Practice, practice.

mercphoto

Second try
Second attempt. This time on black velvet, under-exposed 1/3 stop, Av at f/16, auto-focus, ISO 100, 1/2 second, 100mm, tri-pod mounted with remote shutter release.

Illumination was two natual light incandescants, 40W, custom white balance via grey card.

I noticed when shooting figurines how hard it is to keep reflections of the light bulbs off the glass!

cmr164

mercphoto wrote:

Second attempt. This time on black velvet, under-exposed 1/3 stop, Av at f/16, auto-focus, ISO 100, 1/2 second, 100mm, tri-pod mounted with remote shutter release.

Illumination was two natual light incandescants, 40W, custom white balance via grey card.

I noticed when shooting figurines how hard it is to keep reflections of the light bulbs off the glass!

Marked improvement. You might want to play with the angle.

pathfinder

cmr164 wrote:

Marked improvement.

I agree whole heartedly.

But why did you underexpose? - doesnt' that cause the glass to look more like grey than white? Expose so your histogram is to the right is the rule to follow I thought. Have you tried shots without under exposing?

mercphoto

Crystal

cmr164 wrote:

Marked improvement. You might want to play with the angle.

Thanks. Wondering at what shutter speeds is mirror-lock-up a help. That was 1/2 second with remote release. Kinda hard to tell if camera shook any. Someone had mentioned sharpening it in Photoshop, and while I appreciate the advice, the object itself has soft edges, not sharp edges. The negative to that, hard to tell if the mirror had any reasonable shake in the image, because you can't look for a sharp edge in the image.

The image I posted came straight out of the camera.

mercphoto

-1/3

pathfinder wrote:

But why did you underexpose? - doesnt' that cause the glass to look more like grey than white? Expose so your histogram is to the right is the rule to follow I thought. Have you tried shots without under exposing?

Yes I have, and they don't look quite right. I think what is really happening is the camera is over-exposing, so I'm just correcting it. I've noticed the D300 will do this sometimes. Not by much, just a bit.

I need to put in that D300 firmware hack so I can get histograms, MLU, RAW+JPG...

mercphoto

Zero bias
This is the image at zero exposure bias. Not the exact image but darn close. I shot this, this changed the camera setting and shot again.

cmr164

mercphoto wrote:

Yes I have, and they don't look quite right. I think what is really happening is the camera is over-exposing, so I'm just correcting it. I've noticed the D300 will do this sometimes. Not by much, just a bit.

I need to put in that D300 firmware hack so I can get histograms, MLU, RAW+JPG...

With the dark background the camera will choose to everexpose the glass in trying to calculate an exposure that attempts an overall 18% grey. You are right to correct for that. I don't think mirror lock would make a noticeable difference and since you don't have it at the moment... don't worry about it

pathfinder

cmr164 wrote:

With the dark background the camera will choose to everexpose the glass in trying to calculate an exposure that attempts an overall 18% grey. You are right to correct for that. I don't think mirror lock would make a noticeable difference and since you don't have it at the moment... don't worry about it

If the exposure is via the camera's lightmeter, AND uses an averaging type setting you are correct about overexposing the highlights due to the black velvet, but I thought he used a gray card for exposure since he said he used a gray card for white blaance eg: "Illumination was two natual light incandescants, 40W, custom white balance via grey card. --

Mirror lock is most important for 1/15 or 1/30 of a sec down to about 1 second - depends on focal length to a certain extent. Longer or shorter exposures usually do not need Mirror Lock UP if a tripod is used. Shooting studio shots hand held just does not let you examine the viewfinder nearly as carefully as using a tripod would.

mercphoto

Exposure

pathfinder wrote:

If the exposure is via the camera's lightmeter, AND uses an averaging type setting you are correct about overexposing the highlights due to the black velvet, but I thought he used a gray card for exposure since he said he used a gray card for white blaance eg: "Illumination was two natual light incandescants, 40W, custom white balance via grey card.

I used the grey card only for white balance. I don't know why I didn't think to use it for exposure setting as well. If I'm not mistaken, I would have put it on the aperature I wanted, then seen what shutter speed the camera selected on the gray card. Then resort to full-manual using that very same combination for future shots.

Thanks for the shutter speed and mirror lock up advice.