Fix the input interval
Load an available instrument and keep one chart. Record the symbol, timeframe and dates of two selected bars. Point at them and read their prices in the footer so you can check the same values after switching.
Keep the selected history and time zoom unchanged. Otherwise you would be comparing both a different interval and a different scale. Do not enter the fictional numbers from this article as replacement market data.
A linear scale compares differences
First turn off logarithmic price in the appearance panel. Equal price differences occupy equal vertical distances within the same linear scale.
In the exercise, 100→110 is a change of 10 units, while 200→220 is 20. The second segment is twice as tall on one linear scale. Yet both changes are 10% of their respective starting prices.
A log scale compares ratios
Enable logarithmic price without changing the instrument or interval. Equal ratios of positive prices now occupy equal vertical distances: 110/100 and 220/200 both equal 1.1.
The two fictional 10% rises therefore have equal height on one log scale. Do not compare pixel distances across separately fitted windows as though their bounds were identical; the visible range also affects the picture’s size.
Check values and the limitation
Return the pointer to your recorded dates and read the source prices. The scale switch itself does not recalculate quotes or indicator rules. Labels can move with the price, while the numerical outputs still refer to the same data.
A logarithmic transform requires positive prices. If bars used to fit the scale include non-positive prices, the current implementation uses a linear transform. Do not expect a mandatory warning or an automatically cleared checkbox.
Separate three view controls
Logarithmic scale, vertical price stretching and time zoom have different jobs. The first changes how values are placed, the second stretches the view vertically and the third changes the horizontal interval.
Choose a useful view and follow the separate saved-layout guide. Record which scale you used for an observation. A changed view does not prove a stronger trend, change a trade’s cash result or determine a trading decision.
Primary sources
Sources explain the mechanics and limitations; the editorial examples use invented numbers rather than market quotations.
Your next practical step
Use the workspace guide to open a chart and compare both scales over the same dated interval. Then follow the separate guide for saving its appearance.
Open the first-chart instructions ↗