When looking at a realistic fish drawing, there is a sense of beauty and calmness because the marine subjects are a common theme that invites the audience to relax. This guide will help you create a beautiful and believable drawing of a fish to help achieve this feel.
Using that calm and cool feeling, artists will then use fishes at a motif to introduce a plethora of many different and vibrant colors to bring a sense of wonder and mystic, in a sea of blue, to life.
As there are many types of fishes in the ocean, some wild, some friendly, and some just as mysterious, it is a good idea to study up on the types of fishes that you want to draw.
The hardest part would be detailing the small scales. However, it can be done with a little bit of practice and guidance from a well balanced gesture sketch.
The first step in learning how to draw a fish is to sketch out the type of fish that will resonate with an idea or theme. For example, I like goldfishes because I find them relaxing and beautiful.
On the gesture sketch, I make sure that the anatomy is correct. Most fishes will have two pectoral fins, two pelvic fins, one anal fin, an upper caudal fin, a lower caudal fin, one dorsal fin, and one optional secondary dorsal fin (depending on species).
For your fish sketches, the first layer should have the gesture sketch. Then, create a second layer to fill in the shape of your gesture sketch. The key here is to gesture a dynamic grid that matches with the contours of the body. This is where the scales will go.
From there, block in some simple shading to highlight areas such as the stomach and body curves. Lastly, merge the gestured fish drawing layers together to keep it simple and to get it ready for the next step.
Your gesture lines will become key textures in your fish drawings. The best method is to smudge your gesture lines together so all the colors merge with one another.
Before you smudge anything though, I recommend locking the fish object layer down so you don't smudge outside of its boundaries. From there, using a chalk brush, flare out the fins on the fish and gill areas.
At the same time, start refining the grid along the side of the body to where the scales will be located with basic shading before working on each individual scale. The scales are primarily found behind the gills.
I also suggest painting in some of the fins that are in the background to help you separate it from the fins showing closest to the viewer.
The details are done in two ways: using the regular paintbrush while switching to the smudge brush for more fine details. First, block in some of the shine of the gills with a paint brush.
For the scales, paint in rounded semi circles using your grid as a reference. From there, glaze over the entire body with a unifying value to blend the scales and body together.
For the fins, switch to the smudge brush with 100% pressure. Set the brush type to a very small size and start flaring out the smaller details in the fins to give an impression of tiny folds in the fins.
Again, switch over to a round brush and glaze in a unifying value to blend the colors together. Now would also be a good time to use the dodge and burn tools to bring out more light or dark values.
The final steps in drawing a fish involves bringing out the shine in the scales, the reflections of the water above, and the cloudiness of the water below.
I suggest painting these effects on a separate layer so you can correct it without damaging your fish object underneath. With Photoshop, you can change the layer above the fish object to a clipping mask so it conforms to the fish object's shape underneath.
Otherwise, you can just paint the lights and shadows manually on the different layer and then merge it to the original fish layer. Just make sure to erase any lines that don't conform to the fish object before you merge it.
Using your small brush, switch the type to a splatter head. The splatter effect will create the small shiny parts of the scales. Use it sparingly on the head as well as parts of the round body.
Then, randomly create light squiggles running down the back of the fish to simulate light above caused by ripples in the water's surface.
Lastly, use your dodge and burn tools to finish off your fish drawing by highlighting or darkening colors to meet where your light source is located at. Use these tools to also bring out additional shine found on the scales.