Blink mode and printing in Value Study

Value Study got two new features this week. One I have wanted to add since day one but thought no one would need it. The other I have been resisting for ages. Both are in users' hands now.

Blink mode

Blink mode alternates between the original photo and the value study on a short timer. It is a classic technique for comparing two images: your eye is bad at holding a mental picture of the first while it looks at the second, but very good at noticing what moves when the image swaps out from under it. Differences in shape, value and proportion jump out that you would otherwise miss.

I came up with the idea on literally the first day I started building Value Study. I prototyped it and it did not work. The app processes images in real time and the hardware I was testing on could not keep up with the swap. The flicker was janky, the lag between tap and swap was noticeable, and the whole thing felt broken rather than helpful. I moved on and built the rest of the app instead.

It sat in the back of my mind for years. What pushed me over the edge was a user who wanted it so badly they had wired up a hardware auto-clicker to their iPad so they could project the app onto a wall and have the image flip back and forth automatically while they painted. That is the kind of determination that makes you stop and think. If someone has engineered their way around the lack of a feature with physical hardware, the feature should probably exist.

So I built it. Performance is no longer a problem. The swap is instant, the timing is adjustable, and the auto-clicker rig is no longer needed.

Printing

Printing is the feature I have been putting off the longest. It is also the one users ask for the most.

I kept putting it off because the workaround was already there: save the image to your photo library, open Photos, print from there. That is two extra taps. My reasoning was that the iOS print sheet was one tap away either way, so the feature was not really adding anything. I was wrong about that. The number of people who mentioned it in reviews and emails made it obvious that "two extra taps and a context switch" is a real friction, not a theoretical one.

Once I sat down to build proper print support it turned out to be more than just wiring up the system print sheet. The new export path can include the grid overlay, which the save-to-library path never could. Grid overlay is one of the most useful features for people actually painting from the reference, so having it end up on the printed page is a real improvement over the workaround I had been defending.

What I took from this

Two features, two different lessons. Blink mode was worth revisiting because the constraint that killed it originally was gone and people were finding alternative ways to handle it. Printing was worth building because "there is already a workaround" is a weak reason when users keep asking.

Both ship in the next update.