Midjourney AI – Tweaking Text Prompts to Change Size etc With Parameters

The featured image of ‘parameters‘ was created in Midjourney using the –uplight parameter.

You’ve created your first images in Midjourney – however, they’ve all be square and the same size. How do you go about editing your prompts in Midjourney to create images which closes match your specifications?

Happily, there are a number of parameters you can use to tweak your prompts to give you a range of different options.

This is done by appending certain instructions as parameters to your prompt. These parameters start with two dashes — and must go at the very end of your prompt.

Pay attention to how this is structured as Midjourney will not recognise the command if it is not typed correctly.

You will find a whole host of different parameters listed on the Midjourney document page HERE. However, below I’ve listed some of the ones I use the most with examples of how I use them.

Change the Dimensions of Your Image in Midjourney

You can change the proportions of your image by using the Aspect Ration command. This command is structured –ar x:y. Therefore if you wanted to create an image which had a radio of 3:4 (which would create an image which is taller than wider) you would type –ar 3:4

In the image below you will see I changed the aspect ration to 16:9 using the parameter –ar 16:9

You can type in specific heights and widths too by using –h and –w. If you put in either just –h or just –w it will keep the side that you haven’t specified at the current dimension. Note that this is works best when it is a multiple of 64.

This would be structured as follows:

–h 512 or –w 384

In the example below I set the width to –w 512 which has the affect of making the image twice as wide as it is tall.

The Midjourney documentation recommends we keep this to under 512 to avoid any unusual behaviour.

Image Weight

While Midjourney doesn’t use starter images (init images) to create artwork, we can use images to tell Midjourney what we are trying to create. To do this we use the –iw command.

In my experience this is relatively hit and miss, but it’s fun to experiment with.

To use an image prompt, first you need a url of where the image is hosted. Add this to the front of your prompt.

At the end of the prompt add the image weight parameter which tells Midjourney how much weight you want the image to have.

‘Normal’ is 1, therefore if you ask the image weight to be 2, that is double the normal amount and 0.25 would be quarter.

An example of this might be –iw 0.5 which says you want.

In the example below I set the image weight to –iw 2

For reference, the image I used to start was from Pixabay which I pasted below. The fourth image in the grid is getting close!

Source: Pixabay

Stop Render Early

Sometimes you may want to create a more soft and less developed image than that is created at the end of the full render cycle. We can instruct Midjourney to stop the render early.

The full cycle is 100, therefore if you wanted to stop the render when it is 50% complete, you would use the stop command –stop 50

This is a rerun of the landscape above which I stopped at 50 to create a soft out of focus image

Uplight Upscales

This is a command I use sparingly but I do use it. There will be some types of image I know will need a light upscale as the first upscale will be too harsh and introduce too much detail.

While I do a lot of post-processing and I normally do both the standard and light upscale to blend together, there will be some images this is just not suitable for. I therefore use the –uplight parameter at the end of the prompt which means when this image is upscaled, it will be done so as a light upscale.

As you can see in the example below I used the uplight parameter.

And as you can see below, when the image is upscaled, the uplight upscale option is used automatically.

How often and when you use this will be very much a personal matter.


Another parameter I have mixed success with is the –no parameter. This instructs Midjourney to try to not include the features you request.

The –no command is particularly useful if you are using a prompt that has multiple meanings. The –no can be used to help clarify the prompt.

In the image below, Midjourney did a pretty good job of not including a moon.

However it didn’t do quite such a good job with the prompt below. Here my prompt was ‘a busy city street –no people’. And you will see there are people in a couple of images. I think this is because I was giving Midjourney conflicting messages as most city streets include people so perhaps I was asking too much. If I was doing this again, I might try changing and tweaking the prompt further.


Although these are the parameters I use most often, you may find you favour completely different parameters. The best thing to do is to jump in and experiment.

Try running the same prompt multiple times with different parameters and see the finished effects.

The full list of parameters is on the Midjourney website here – jump in and have fun experimenting 🙂

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