Photoshop (and other image processing) Tips.

[Tandum (Robin)]

Wouldn't it be nice if there was a section on Photoshop Tips. It appears to be the tool of choice. I have no idea on how to keep the chit chat out but things like : holding down the ALT key when moving the white point in levels shows clipping in the colour that you are clipping with the movement : are not common knowledge and are not documented.

[iceman (Mike)]

That is a nice tip!
More and more tips can be added and then converted into an article (minus the chit chat).

[Ric]

A good idea Tandum, even though I use Paintshop Pro I find a lot of these tips and ideas can be easily converted for use.

Cheers

[dugnsuz (Doug)]

Great idea.
Mike, tie jase down to a chair and apply the thumbscrews to get every last bit of processing know-how out of the man!!

[jase (Jason)]

Originally Posted by dugnsuz

Great idea.
Mike, tie jase down to a chair and apply the thumbscrews to get every last bit of processing know-how out of the man!!

Not the medieval torture...

Here is a couple to make a start (basic ones first).

Double clicking the grey background in PS is a quick way of bringing up the open file dialog box.

Use spacebar to activate the "grabber" to move around the image (everyone knows that surely)

When using masks (either hide - black mask or reveal all white mask), use the X key to switch the white/black palette. If you've used a colour select function and the white/black palette has changed, use the D key to change it back to the default.

Talking masks. If you want a closer look at your mask, present the Alt key while you click on the mask in the layers panel. It will open and allow you to make finer adjustments.

When working with selections, use the Control+H key to hide the selection edge/lines. Push it again to bring it back. This is great when selecting stars to work on as the selection can sometime be distracting. Just remember that you've still got the selection active.... it is still active even if its hidden. I think its Control+D to deselect.

On the topic of selection - star selection (an alternate way to using the colour range tool)

Make a grayscale copy of the image. I'll call this image #2.
High-pass filter image #2 with a radius of one pixel.
Apply a Gaussian blur to image #2 with a radius of one pixel.
Invoke Image->Adjust->Threshold.
Adjust the Threshold Level one click at a time until just the stars are white and everything else is black.
In the original image, in the Channels Palette, create a new channel. Name it "Stars." Choose "color indicates masked areas."
Paste image #2 into this channel.
Make just the RGB channels visible (i.e. make the Stars channel invisible).
Discard image #2.
In the original image, invoke Select->Load Selection. Choose the Stars channel you just created.
Invoke Select->Expand and expand the selection by a few pixels (e.g., three). Done. I'm not sure of the source of this, I think it could have been Russ Croman.

Tip...of the iceberg perhaps, but its a start.

[iceman (Mike)]

Nice work! I hope others continue to contribute tips here.

To make sub-pixel alignments when aligning your RGB channels, increase the image size by 400%, giving you 1/4 pixel alignment ability. When it's aligned to your satisfaction, reduce the image to 25% (back to original size).

[sheeny (Al)]

Here's another one I'm sure everyone knows (well I know someone won't, that's the point of posting...)

When using the brush tool (even when masking - which is what I use it for most) use the [ key to reduce brush size, and use the ] key to increase brush size.

[mdgodf (Mark)]

Pick up one of Scott Kelby's books...or visit his web site at http://www.scottkelby.com/ for lots of photoshop tips.

[jase (Jason)]

ok, here are a few others I use. Geez I feel like I'm coming clean on some of the tricks.

Capslock key will change your pointer into accuracy mode (target cross hairs). Great for highlight masks and other features. Push it again to change it back.

When you are working with layers that aren't aligned and you want to align them, press and hold the control key... it will change the current too into the move too until released.

Control +/- will resize the image. Control 0 or any other key will active fit to screen function

Control+J duplicates the currently selected layer.

When using the a select tool - say the elliptical marquee tool, hold down the space bar to move the selection around. This makes it easier to frame aspects of the image i.e. a halo/reflection of a star you wish to remove.

A request for a CS2/CS3 user... can you create an adjustment layer on a layer mask (say reveal all mask for instance)?

[leon]

Gees guys I'm lost already.

Leon

[Bassnut (Fred)]

Top idea, a single no chat source of PS tips. Like Jase, ive picked up so many crackers over a long period of time (not that it did me any good ) . To be able to see tricks in one place them without stumbling over them by accident over a lifetime would make a nifty seperate catagory.

[iceman (Mike)]

For sure. Once we've got a sufficient supply of tips in here i'll put them into an article that will be added to over time.

It would be perfect for the Wiki idea, in the future

[Bassnut (Fred)]

No Mike, please not a Wiki format, that sucks .

[dugnsuz (Doug)]

Make this a Sticky Mike???

[Glenn Dawes]

Hi guys,
I think a photoshop tip thread is a great idea! So here's my 2c worth. Some may think it is basic but I'm hoping someone might appreciate it. Many of the lunar images in the yearbook, over the years, have been done this way.

Regards

Glenn

CREATING MOSAICS IN PHOTOSHOP

1 Open the first image and expand the canvas to a size to cover the whole Mosaic
IMAGE > CANVAS SIZE. Move the image to its correct position (drag the square) before resizing (width and Height)

2. Open second image SELECT > ALL

3. SELECT > MODIFY (specify border between 5 – 10 pixels)

4. SELECT > FEATHER (enter same number of pixels as 3. above)

5. SELECT > INVERSE

6. EDIT > CUT

7. Close window and EDIT > PASTE into your first image you resized. A new layer will be automatically created on top of the original.

8. LAYER > LAYER OPTIONS. set opacity level to 50%.

9. Merge images to your satisfaction using the “Move Tool” and if necessary Rotate using LAYER > TRANSFORM > ROTATE.Then set opacity back to 100%

10. Repeat steps 2 to 9 for remaining images

11. Using IMAGE > ADJUST > CONTRAST/BRIGHTNESS or CURVES Match the appearance of the layers (remember to “click” the layer you wish to adjust).

12. Save document as a Photoshop document (to allow you to return to it if necessary)

13. Flatten Image LAYER > FLATTEN IMAGE. You can no longer modify individual layers, however you can now crop (using IMAGE > CROP) and process image (eg. IMAGE > ADJUST > Contrast/Brightness) as a whole and saved in whatever format you need ie. FILE > SAVE AS (then Tif).

[xstream (John)]

Originally Posted by dugnsuz

Make this a Sticky Mike???

Done!

[Garyh]

Boy I like this thread!
I`m learning a few new tricks here!
cheers Gary

[dugnsuz (Doug)]

Originally Posted by xstream

Done!

Thanks a lot - this is going to be a great resource.
Now, no more chit chat from me!!

[jase (Jason)]

Alternate method to performing HaR combinations - courtesy Don Goldman:

Create RGB and Ha Tiff files in Camera control software of choice i.e MaximDL, CCDSoft etc.
Process both in PS CS until about 80% finished
Split channels in the RGB
Layer Ha over R channel with normal mode and 30% opacity
Use HaR as red channel and combine RGB
Finish RGB processing
Finish Ha as Luminance
Saturate RGB by 30%
Paste in Luminance (Ha) using luminosity mode
Duplicate the RGB and use as top layer in soft light mode with 20% opacity

The above works quite well.

Noise invert mask "NIM" - courtesy ME

When close to the final steps of processing duplicate the flattened image
Create a layer mask on the duplicated image (reveal all)
Copy the original image
Click on the mask while holding the Alt key to fit the mask to screen
Paste the original image into the mask (it will turn grey - which is normal for masks)
Inverse the masked image ( the background turns white, while features grey or black)
Use levels on the mask to increase/decrease the mask size/impact.
Select the layer that has the mask applied
Apply a moderate to heavy noise reduction of your choice (X blur, dust&scratches, neat image, whatever)
If its too heavy, drop the opacity from 100% and/or duplicate the original layer again and use lighten mode to bring some stars back (if required).
NOTE: With the inverted mask anything that is black is not pushed through the noise reduction function. Use the levels slider wisely. You can also paint the mask to ensure certain areas i.e. details, stars, blah blah are masked as needed.
Flatten and enjoy. You don't have to wait until the end of the routine for this. It can be applied if you've got plenty of layers. Choice is yours.

That will be all for now. May provide more later.

[Tandum (Robin)]

Highlight Mask or Brighten DSO. This lets you brighten up a DSO without effecting the sky and stars.

Press Control-J. (Layer via Copy).

Select all of the original image and copy to clipboard.

Layer > Layer Mask > Reveal All. (Create a layer mask).

Alt Click on the new layer mask icon in the layers palette and paste, then invert that layer. Image Adjustments > Invert.

Increase the contrast of that mask with levels or curves. Move the black point to about 64 and the white point to about 220. Experiment with these points.

Apply a small gaussian blur to the mask.

Select the original image and drag the white point to the left in levels to brighten the DSO.

The opacity of the layer may also be adjusted.

Flatten the image when done.