Stacking with CS4 - Jerusalem Cricket

Images taken in a controlled environment or with a posed subject. All subject types.

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Bob
Posts: 17
Joined: Tue Feb 26, 2008 6:30 pm
Location: The Sea Ranch, Ca.

Stacking with CS4 - Jerusalem Cricket

Post by Bob »

Image


I just received my Adobe CS4 software today and I had to try the new stacking feature.

Last week I found this Jerusalem Cricket in my garage. I knew the new software was on its way so I put the cricket aside and then took a series of images about 4 days later when I had time (unfortunately it has started to dry out in the meantime). Then tonight I loaded the program and combined the images. This is a stack of 13 images with a focus range of about 1½ inches with no other Photoshop work other than very slight cropping and sizing for the web.

This is the first time I have ever tried to use a stacking program so I have no basis for comparison. But my general impression is that this program has potential but it didn’t quite make it on this try. The upper antenna is sharp but it has an out of focus halo around it. If one looks closely one can see this problem in several other areas as well (but not as pronounced). I assume it would be a very simple matter to go into the individual layer masks and do a little selective painting to cure this problem but I have not tried this as of this time.

I can clearly see that I have found a new way to spend some my time in the future.

Canon 40D, 100 mm macro, available light, 1/13 sec, f/13 and one good looking bug.

Bob

augusthouse
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Location: New South Wales Australia

Post by augusthouse »

Bob,

This is enlightening! If this is the type of result that PS CS4 is helping you to achieve then I for one am impressed!

The glass is more than 1/2 full.

Could you do a pixel-crop (view>actual pixels) of a few areas of the image and upload them, particularly the "halo" you mentioned?

When uploading feel free to use the full 200KB allocation.

I like the way the cricket is positioned over the layers of leaves.

Craig
To use a classic quote from 'Antz' - "I almost know exactly what I'm doing!"

Bob
Posts: 17
Joined: Tue Feb 26, 2008 6:30 pm
Location: The Sea Ranch, Ca.

Full size crops

Post by Bob »

Image
Image
Image


Craig,

Thanks for your comment. I agree that this is very promising. I was going to go back and try playing with he masks but found I had flattened the image before saving which is something I “never” do :roll: . So I will therefore have to go back and regenerate the composite again. It will be interesting to see how the two results compare.

The three images above were cropped from a full size image without any resizing. The only thing I have done was to convert to 8 bits and then save as a jpg. I hope this helps.

Bob

rjlittlefield
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Post by rjlittlefield »

These are interesting defects. Many stacking programs have trouble with halo, so that's not surprising at all. What is a bit odd can be seen in the first blowup. There is no visible halo where the antenna overlaps the leg, but there is significant halo around the rest of the antenna. Oh...wait...this is an unmounted dead cricket...so probably the antennae actually collapsed down until they are touching the legs...in which case the lack of halo there is not surprising at all.

I think you would find that the specialized stacking programs have less trouble with these problems than Photoshop does. The drawback is that they have unfamiliar interfaces, and some of them cost money to license. It definitely looks like Photoshop CS4 provides a good way to get started in the game!

--Rik

augusthouse
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Post by augusthouse »

However, with PS CS4 we still have all the original pixels available if required (non-destructive), and a host of other Photoshop tools such as layer blending modes to work with in addition to its stacking abilities.

Also, it does not appear that there are other processes being forced upon the image such as program generated noise reduction, contrast and vibrancy shifts and detail smudging.

We can move around and between the layers rather than being restricted to a merged composite.

Thankyou for the pixel crops Bob.

Craig
To use a classic quote from 'Antz' - "I almost know exactly what I'm doing!"

P_T
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Location: Sydney, Australia

Post by P_T »

If it's true, that's amazing!! It'll be a lot easier to fix and with better result than just cloning out the artifacts.

One more thing I notice, PS usually does a better job at aligning images than focus stacking software... but maybe that's just me.

Bob
Posts: 17
Joined: Tue Feb 26, 2008 6:30 pm
Location: The Sea Ranch, Ca.

Post by Bob »

I reprocessed the individual images that I had previously used in my original post and got the same halo effects. I also tried another set of images and again got the same effects as seen below.


Image


I then decided to have a go at cleaning up these problem areas. After several false starts I realized the one should just make a selection of the problem areas (in this case I selected the outline of the total cricket and inverted the selection) and then paint on the individual layer masks.

Viewing a single layer at a time, I activated its mask and painted out any of the areas that were out of focus on that layer with a black brush. This process left a lot of small voids in the composite image. After cycling through all of the layers and reworking the individual masks, I went back through the masks again one at a time. This time when I located a layer that had a correct focus corresponding to a void area I activated its mask and just painted the void area with a white paint brush.


Image


Some thoughts on this process: You have total control of the process and you can make the end image as good as you want. You just have to take a lot of care in selecting the focus vs non-focus interface. Care is also needed in selecting which areas to paint back into the void areas. I also think it would help to feather the initial selection slightly to help blend the interface - something I did not do this time.

I am happy with this attempt to date but plan to revisit this stack when I have more time to do a better job. Below is the final image.


Image

I have some more testing to do but I think the halo is caused by the lack of detail and/or contrast in the background. If you look at the antennas, you will note that they are not close to the legs or the leaf. They do not have a halo in that area of the legs but they did have a halo where they are silhouetted against the leaf.

Comments and thoughts please.

Bob

augusthouse
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Location: New South Wales Australia

Post by augusthouse »

Bob,

Thanks for uploading your results and the detailed outline of the process.

When working with the individual masks have you been utilising the 'Refine Mask' option?

Radius Determines the size of the region around the selection boundary in which edge refinement occurs. Increase the radius to create a more exact selection boundary in areas with soft transitions or fine detail, such as those in short hair or fur, or blurred boundaries.

Contrast Sharpens selection edges and removes fuzzy artifacts. Increasing contrast can remove excessive noise near selection edges caused by a high Radius setting.

Smooth Reduces irregular areas (“hills and valleys”) in the selection boundary to create a smoother outline. Enter a value or move the slider from 0 to 100.

Feather Creates a soft-edged transition between the selection and its surrounding pixels. Enter a value or move the slider to define the width of the feathered edge from 0 to 250 pixels.

Contract/Expand Shrinks or enlarges the selection boundary. Enter a value or move the slider to set the amount from 0 to 100% to expand, 0 to ‑100% to contract. Most useful for making subtle adjustments to soft-edged selections. Shrinking the selection can help remove unwanted background colors from selection edges.


Craig
To use a classic quote from 'Antz' - "I almost know exactly what I'm doing!"

Bob
Posts: 17
Joined: Tue Feb 26, 2008 6:30 pm
Location: The Sea Ranch, Ca.

Post by Bob »

Craig,

Generally I use this function and have found it to be very useful. For some reason I did not use it on this stack correction.

I am looking forward to trying to do a very careful job of masking the cricket in the near future. I think the macro hairs on the antenna will be a problem but that an opportunity to learn.

Thanks for your interest and comments.

Bob

P_T
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Joined: Sat Jul 19, 2008 1:13 am
Location: Sydney, Australia

Post by P_T »

One more thing I noticed about PS is that it tends to tweak the colours in your images to blend them in together. That happened to me when I was doing panorama stitch, as I play around with the mask, i noticed some jagged area where the colours/saturation/contrast/etc has been changed. Is it like that with stacking in CS4?

Bob
Posts: 17
Joined: Tue Feb 26, 2008 6:30 pm
Location: The Sea Ranch, Ca.

Post by Bob »

Have not noticed this but I have not spent that much time with Photoshop stacking to date. I will look to see if this is a noticeable effect.

Bob

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