Practicing The Craft And Finding The Beauty: 17 Shot Stack Orb Weaver And Web

[JBW]

This young Orb Weaver is two and one half inches leg tip to leg tip. If she reaches her full potential she will reach about nine inches tip to tip and her web will be strong enough to snare small birds. Nine times out of ten the web is in front and the view is of the belly. I'm extremely happy to get this colorful shot of the upper body.

As always this shot comes from our garden/temple somewhere in the Philippines.

Sony Alpha a68 ~ Tamron 90mm 272E Macro Lens ~ ISO 100 ~ Shutter Speed 1/3s ~ F/9 ~ Exposure Compensation From 0.0 to -1.7 ~ Natural Light ~ Stacked In Fiji

[Round Tuit]

Hi Brian,
I don't understand the technique that you use to get this shot. I would expect a focus stack of 17 shots at f/9 to have the whole spider in focus. As it is, the tips of a couple of legs is quite soft. What is the purpose of varying the exposure between shots?
Would you mind explaining?
BTW nice picture.

André

[DanK]

My reaction is the same as Andre's. Perhaps you didn't change focus enough between shots. When you look at the stack, before creating the composite, a photo at one and should have in focus the nearest point you want in focus, and the one at the other end should have the farthest. 17 shots at f/9 should be able to cover quite a distance.

[JBW]

Look at the marvelously deep and rich colors in this shot. Or even better check out this cropped image of the same shot.

Exposure stacking with long exposures allows me to get this depth of color and softness.

I did not use filters and I stayed with natural light and while my shutter speed was not minutes long it was long for live bug work.

It would be possible to combine exposure stacking with focus stacking but I'll wait for my focus rail before i try it.

[DanK]

I assumed you meant focus stacking. I assume Andre did too.

Exposure stacking is a good way of removing noise, if you need to. As far as I know, it has no impact on either color or softness. It is simply a way of averaging pixels that are the same place, which is what removes the noise. It takes advantage of the fact that much of the noise is random, appearing in different locations in different ones of the images you blend. Median blending in photoshop is much the same principle: something that shows up in only one or two of a series of photos won't be the median pixel value and isn't included in the composite.

This doesn't affect color, and if the camera isn't moved between shots, it should not lessen sharpness (or increase softness). Note that the article you linked mentions neither improving color or generating softness.

If you use really long exposures, far longer than you used, you can get what are essentially hot pixels. AFAIK, exposure blending won't help with that, despite what the linked article says, because it has no impact on noise that is in the same location in each shot. That can be taken care of by what is called, at least in the Canon world, long-exposure noise reduction, which takes a black frame of the same length and, since the bad pixels appear in the same place, subtracts those from the original issue. You wouldn't need this for exposures of the length you had here.

[JBW]

I assumed you meant focus stacking. I assume Andre did too.

Exposure stacking is a good way of removing noise, if you need to. As far as I know, it has no impact on either color or softness. It is simply a way of averaging pixels that are the same place, which is what removes the noise. It takes advantage of the fact that much of the noise is random, appearing in different locations in different ones of the images you blend. Median blending in photoshop is much the same principle: something that shows up in only one or two of a series of photos won't be the median pixel value and isn't included in the composite.

This doesn't affect color, and if the camera isn't moved between shots, it should not lessen sharpness (or increase softness). Note that the article you linked mentions neither improving color or generating softness.

If you use really long exposures, far longer than you used, you can get what are essentially hot pixels. AFAIK, exposure blending won't help with that, despite what the linked article says, because it has no impact on noise that is in the same location in each shot. That can be taken care of by what is called, at least in the Canon world, long-exposure noise reduction, which takes a black frame of the same length and, since the bad pixels appear in the same place, subtracts those from the original issue. You wouldn't need this for exposures of the length you had here.

Assumptions are always dangerous.
From astrophotography I'm familiar with long exposure and black frame shots.
I did not move the camera.
I'm quite willing to listen to any explanation you care to offer for what caused the effect.
Brian

[Round Tuit]

Assumptions are always dangerous.
From astrophotography I'm familiar with long exposure and black frame shots.
I did not move the camera.
I'm quite willing to listen to any explanation you care to offer for what caused the effect.
Brian

I think that your stack is giving you the average exposure of your 17 shots. If your EV steps were equal then the middle shot should look like the stacking result. If you still have the middle shot, it would be helpful to do the comparison.

[JBW]

I think that your stack is giving you the average exposure of your 17 shots. If your EV steps were equal then the middle shot should look like the stacking result. If you still have the middle shot, it would be helpful to do the comparison.

I do have it and have compared it. Admitted one is pre processing and the other is post but they are certainly not the same shot.

[JBW]

Would it make sense to think of this as an HDR shot? Different exposures with their different contrasts but equal sharpness combining to create a deeper richer shot?

[Stagecoach]

Would it make sense to think of this as an HDR shot? Different exposures with their different contrasts but equal sharpness combining to create a deeper richer shot?

Brian, I think you have to clearly differentiate between any 'change' with respect to sharpness/DOF AND 'merging' different exposures.

I'm thinking your analogy of the procedure as HDR similar is along the right lines.

[FootLoose]

Regardless of the technical discussion, the bit in the middle does look good.

[JBW]

Regardless of the technical discussion, the bit in the middle does look good.

Absolutely