I am going on a trip to the Yucatan in May and want to take good pictures inside some of the Cenotes (sinkoles that expose groundwater underneath). Some of these cenotes are underground with not much light (Beams of light from the sun come through from the holes at the top of the cave, and some stationary artificial lighting is provided from the people who work at these caves as well).

So my plan is to use my Rokinon 12mm f2.0 with my Sony A6000 on a tripod and set it to max aperture and long exposure, with maybe ISO of about 400 to 800. Do those settings sound about right to get some good low-lit cave pictures? Would there be any reason to lower the aperture? Keep in mind, I do not plan on going any further and setting up external light sources, etc. The cave should be lit enough to be able to grab a decent picture with long exposure.

Anyway, the more important question or concern I have comes into play when I want to get some action shots. Long exposures and people moving don't mesh, so I have to take a short exposure frame with flash from the same angle with the person, and then insert that person into the long exposure photo. For example, freeze the person when jumping into the water (in the air mid-jump). I think the only way to do that is with a computer program using layers or masks, correct? I don’t want to purchase anything, and I think this can be accomplished with GIMP on my Macbook pro.

Last night, I tried masking myself out of a picture (or whatever the term is), but it was very hard to do in terms of being precise. I tried to fiddle around with the lasso and the different detections (color/shape/contrast), to no avail. Maybe part of that was because I was on a small laptop without using a mouse. But I think most of it was because I am an extreme beginner and this is my first time playing around with photo editing tools.

Can someone please point me to some detailed Gimp tutorial videos either showing how to accomplish exactly what I want from start to finish (Add the frozen person from the short exposure frame to the long exposure frame), or if you don’t know of a video that explains all of that, then maybe some tutorials on something similar, like how to precisely mask out people.

UPDATE: I have included a picture of what I am trying to accomplish. The cave in question is pretty dark, so I am almost positive he used the method of layer masking to insert his self into a long exposure shot of that cave, from a short exposure flash induced shot with the same angle

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I have an image with a white background.
How do I make it a transparent background?

   
I'm trying to make a new decal from my vintage outboard. I'm using Gimp 2.8.
It's almost good enough (for me) but I'm having trouble getting the bottom border
radius' looking natural like the top corners, but otherwise, I have it shaped like
the original. Help or suggestions appreciated, Thanks!

P.S.- My off white "background" make it hard to even distinguish the
border on this forum. ..... not sure what I can do so you can see
the problem better.

Hello

I do hope someone can help me with this problem that is really frustrating:

GIMP works great in most instances and I have been using it for a few years without any real glitches.

However this past few weeks, the LASSOO TOOL has been plagued with glitches: straight lines are usually fine, but anything using a curve usually sees the lassoo tool closing far too quickly, making undesired shapes I have to close and 'fix' later,

Up until very recently, the lassoo tool worked like a charm, even with rapid use.

I done a clean reinstall of WINDOWS last week [nothing to do with this problem] and the oversensitive closing/ bad lassoo drag is still there .

So I dont think its my computer which seems to work fine otherwise.

I also reinstalled GIMP 2.8 and even went back to 2'6 to see if that worked better, but alas it is still the same.

Is there a recent setting or something I can adjust, or any other steps I can take to get the lassoo tool working well like it used to? I can still work, but I am slowed down a lot compaed to what used to be standard work practise.Will check for responses later.

Attached is the sort of images I create with the help of GIMP:

Kind Regards, Rob
This post has been edited by Rab Smith: Today, 10:50 AM

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Hello,

does anybody know about an accessible systematic comparison between Krita and GIMP?

I know about the general differences like photo editing - GIMP and painting-Krita and the raster graphics editor comparison on wikipedia, I know some differences from my personal use, but maybe somebody has a more systematic argument list with ad- and disadvantages?

Or what could be arguments for GIMP and against Krita? (Personally I'm using both of them but in case of less experienced users and less flexible workspace I need to decide and argue)

Thanks and regards,

Adriana

Hello. I am trying to do an ImageMap . I am using polygon selection. Do you know if there is a way that can select an area (maybe by color or by magic wand) to find the coordinates? Polygon selection is not the best solution.

Hello there,

I am using Gimp 2.9.3 downloaded from http://www.partha.com/ and I am looking for a script to change the Color Temp of a layer. I have founded this script "colortemp" and installed it but unfortunately it's not working with my version of Gimp.

Error Messages are:

Error: eval: unbound variable: RED-LUT

Plug-In 'Convert Color Temperature' left image undo in inconsistent state, closing open undo groups.

The window of this script is:

Script URL: http://registry.gimp.org/node/73


My goal is to get this result which is a photo of my screen :

(Left with Color Temperature changed - Right side: Original colors)

I have noticed that some of my artworks are more beautiful with the soft SunsetScreen which change the colour temperature of my screen on night :


I have noticed the new option Color Temperature of Gimp 2.9.3 but the result is all the time too dark.

Thanks,
Vincent.

Hi, I'm using GIMP 2.8.16 and have just downloaded three brush packs from Texture Mate and have no idea how to add them to my GIMP.

I downloaded a pack some time ago and when I unzipped the file there was a folder called brushes which contained a dozen or so brushes. All I did was copy & paste them over to the brushes folder in my GIMP folder and everything worked great.

This time, though, when I unzip each of the files I downloaded from Texture Mate, all that's in there is a jpeg of the brush pack preview, and an ABR file (whatever that is) with the brush pack's title, i.e texturemate-treebranches1.abr

What am I doing wrong please?

Editing GIF is possible, but... the GIF is an indexed-color format, pixel colors are coded on one byte (256 values) that are really indexes into a "color map". So you have a maximum of 256 colors across all frames(*). When you are in indexed-color format, there are several restrictions:

• Many filters and tools won't work (and will be grayed out in the menus)
  
• Layer opacity is binary (fully opaque, fully transparent, there is no partial opacity)
  
• All the colors you add are mapped to the closest existing color in the color map, so your blue may well turn red if there is no blue in the initial GIF... and for the same reason, the colors of whatever you paste in are also mapped to colors in the color map.
  

Hi all, I'm new to the forum and new to Gimp.

I'm a blacksmith and fabricator, and what I want to do is print life size drawings of objects from images so that I can use them as templates for cutting steel etc..

So lets say I wanted to make a replica of a knife from a picture. I import the image, cut round the knife, re-orientate it and correct perspective(if necessary), re-scale it to real life dimensions, create a line drawing version and print it out. I also need to be able to print things which cover more than one page for large objects, even things which could be a metre long or more.

I had a bit of a go but quickly started to come unstuck. I was able to draw round the knife, but I couldn't make it a new layer of it's own. Also when I rotated it, the top and bottom were outside of the layer boundry and I couldn't figure out how to stop it cropping the image.

I can probably do the line drawing bit ok. Unless I need specific angles and symmetry. But I'll figure that out when it comes up.

If anyone can point me in the right direction that'll be awsome!

Cheers