Optimized Media & Render Cache Resolution

Hi all,

My current workflow is to use Optimized Media (OM) for my larger projects. I prefer to use 10-bit files at 1/2 resolution, so I can do a bit of basic grading while I work, while retaining a 10-bit image. I have my OM settings set to DNxHR HQX / Half Resolution. I also like using Render cache on clips with TNR. I have my Render Cache Format also set to DNxHR HQX. There is no option to change the resolution for Render Cache.

My question is, I've been checking the box "use render cache" in my export settings to speed up exports because I figured that Resolve would be pulling from high quality preview files, since I chose a high quality codec setting for my Render Cache Format. Can I assume that the render cache files are the original media, or at least at my timeline resolution? I often work with 4k and 6k in a 4k timeline.

The thing that makes me think that my process is okay, is that when I toggle "Use Optimized Media if Available" off after creating render cache, Resolve doesn't need to re-create render cache. This makes me believe that it is using the original media to create the cache files. I cannot find this in the manual and am just wondering if anyone can confirm that I am correct. I obviously do not want to be using half resolution render cache files for my final export.

Thanks!

Very curious to know if anyone can answer the above question. There's no setting for cache render resolution, and seems to be no information about this in the manual.

My source footage is 4K ProRes 4444 XQ, and I'm using optimized ProRes 422 HQ 1920x1080 media in a 1920x1080 timeline. When exporting ProRes 422 HQ files, I would like to save times by checking "use render cache" when exporting. Can I assume that my render cache is 1920x1080?

I'm using Resolve 17.2.2 on an M1 Mac Mini...

I believe Cache operates at the timeline resolution.

I honestly don't know of Cache will pull from the Proxy, Optimized, or Original.

My expectation would be it pulls from the Proxy or OM. Kinda the point of having those is to speed things up. If Cache is pulling from the Original, that seems to defeat the point of having the Proxy or OM.

I would suggest reading the User Manual to understand how the Optimized Media and Render Cache work.
Optimized media has codec and quality settings in the project preferences.
Render cache frame size is always the timeline size and it's quality is dependent upon the codec choice.

When using the Deliver page the Use Optimized Media and/or the Use Render Cache will use those for final render instead of the original media. This can be a problem if using low quality settings for better playback.
I always do my final renders using original media only as it guarantees the best quality output.

I always do my final renders using original media only as it guarantees the best quality output.

My philosophy as well.

In some cases I find it useful to set optimized media at a better codec e.g. Dnxhr with a high bitrate instead of h.264, in order to perform demanding color effects and than use said OM for the final render.
This has become more difficult as a work flow since I can't see which clips have optimized media and at what resolution. Now, I am obliged to render at the higher bitrate codec, re import, perform whatever changes and render the final version.
I would definitely like being able to see the optimized media column as before.

I always do my final renders using original media only as it guarantees the best quality output.

My philosophy as well.

Thanks for the replies!

I just discovered another reason not to use the render cache when exporting files. Two days ago I exported a timeline with lots of Open FX filters along with color grades. Render cache was set to "smart mode," and basically every clip was in the render cache. I exported with "Use render cached images" turned on. To my surprise, in the exported file three or four shots (out of a few hundred in the timeline) looked wonky because they were missing a color node - and yes, I double-checked that all the nodes were turned on. What's particularly weird is that the rendered clips when viewed in the timeline all looked and played fine, so that the render cache itself presumably contained all of the corrections. Anyway, I've learned my lesson...