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I've tried the solution in this post but haven't been able to resolve so hoping that someone here might be able to help.

I'm attempting to create a buffer layer of 5km radius around a collection of pinpoints that I have in a separate layer.

The layer that has the pinpoints I want to buffer is in CRS EPSG:4326 - WGS 84, but my overall project map is EPSG:3857 WGS 84 / Pseudo Mercator.

If I change the layer with my pin points to 3857, all the pinpoints relocate to one pinpoint on a completely different continent. If I change the overall project to 4326, my base map (Open Street Map) distorts and stretches horribly.

Based on previous answers on older versions of QGIS I've also looked for On-The-Fly projections settings but they don't appear to be here - I've tried both Project > Properties > CRS and also Settings > Options > CRS as suggested in a duplicate thread, but it's not in either spot.

How can I get circular buffers from my pinpoints that doesn't horribly distort my base map, or make my pinpoints disappear into the sea?

I've found a workaround which is to make a radius circle using symbology, but this obviously isn't ideal because it means I can't use the added benefits of a buffer, like being able to count the number of pinpoints from another layer that fall within the buffer.

QGIS 3.12.3 Bucaresti Mac 10.15.5 Catalina

Vince
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Junta
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    don't use setCrs to change the projection of your map and don't use 3857 to do analysis in as it distorts the further north or south you go. – Ian Turton Dec 11 '20 at 16:27
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    try https://gis.stackexchange.com/questions/77332/set-projection-crs-in-map-and-shapefile-to-produce-buffer and see if it helps – Ian Turton Dec 11 '20 at 16:30
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    "my base map (Open Street Map) distorts and stretches horribly": all maps are distorted (horribly or not...) - get an understanding what projection is best for your project "On-The-Fly projections settings don't appear": QGIS does this automatically today, that was something you had to set in older versions "I change the layer with my pin points to 3857": You set the CRS, but you should reproject it (rightclick on layer, save as, select CRS) "circular buffers from my pinpoints": circular on the map canvas? Or circular on the globe/real world (geodesic circles)? – Babel Dec 11 '20 at 16:30
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    See: https://en.wikipedia.org/wiki/Tissot%27s_indicatrix - I guess you want something like picture 2. Be aware that those circles are NOT geodesic circles. So depending on what you use them for, a non-circular form on your map canvas is better suited. Read: https://www.esri.com/news/arcuser/0111/geodesic.html – Babel Dec 11 '20 at 16:30
  • Check out https://gis.stackexchange.com/questions/378174/making-a-rectangular-vector-shapefile-that-is-a-perfect-square-in-qgis/378176#378176 its about squares, but the same goes for circles – MrXsquared Dec 11 '20 at 16:48
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    The proper shape of a buffer circle in many projections isn't a circle. If is isn't ovoid in decimal degrees (plat carré), then the buffer has been deformed and contains incorrect coordinates. If you insist on perfect circles in every projection, then it will be wrong in most of them. – Vince Dec 12 '20 at 14:19
  • @babel Thank you for your answer. I've re-projected the layer as you described and am now seeing circular buffers as I'd hoped for. Much appreciated! – Junta Dec 16 '20 at 15:12
  • @IanTurton and Vince Thank you both for your comments also. I take your point ovals being more accurate based on the way map projections work. However I am working on the level of 1km and 3km radii, and wasn't anticipating the ovals being so severe, especially at this local level. All the examples provided talk about '000s km scale for e.g. However I'll look at both oval and circle buffers and see what comes out. Very grateful for your answers. – Junta Dec 16 '20 at 15:17
  • OK so Ive used babel's method to create the circle buffers, but they're coming out much larger than the circles created using symbology. The buffers are set using Distance > 1.000 > Kilometers, while the symbology is set using Simple Marker > Size: 1000 > Metres at scale. The buffers are almost twice as large as the symbology circles I've created - why is this the case, and which is more accurate? Thanks again for your help. – Junta Dec 16 '20 at 15:30

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