Michael,
You might also look at Fast Raw Viewer- it will render .tif files, although if you're using your Z7 and/or D850 and obtaining .tifs of a bit over 260MB each you're well over the published recommendation -
The following is from the Fast Raw Viewer Manual (libraw.com or fastrawviewer.com)
• RAW files 60-150 Mpix (RAW files are larger than 120MB):
o SSD/NVME (M.2) storage
o 8+ core processor
o 32 GB RAM.
o Discrete video card with a price tag around $200.
"I have a pretty fast computer" can easily mean different things to folks with differing needs. The computer that I currently use for photographic post processing has 2 10 core/20 thread (each) processors running at a nominal 3.6 GHz, 256 GB ECC registered RAM, storage on this "box" is about 1.5 GB of SSD (this is RAID 1- I'm willing to pay the performance penalty in exchange for data integrity- this has saved my work more than once!) with a further 12 GB (RAID 5) on hard discs, the video card is an NVIDIA Quadro M4000 (8 GB SDRAM). Offline I have both backup and archives. This computer runs Windows 10 Enterprise 64 though my (offline) backup & archive computers run Free BSD 12.1.
In addition to photographic activity prior to my retirement I worked as a mechanical engineer. This computer was purchased to aid in analyzing basic structural and thermal characteristics of models of real world parts and assemblies.
When I start Fast Raw Viewer and point it to a directory that contains many "oversize" .tif files a warning?! appears "Dimensions Too Large" appears, but at least on my computer the program works very well. How well? In the automatic slideshow mode I view each .tif image at an interval of 1 second- I've found that this particularly useful to cull any image from a potential stack that has been affected by vibration. Though I do not live particularly close to railroad tracks I've found that when the ground is frozen vibration of either the camera or the subject or both can become an issue before I can hear an oncoming train.
Calling each image from it's thumbnail takes a bit longer: I can manually go through a stack as fast as 1.5 seconds per image (if I can "see" that quickly) while looking for other problems such as inconstant light on a subject (perhaps the reduction in speed is due to my age and arthritis).
I can't guarantee that Fast Raw Viewer will work for you as well as it does for me; that will depend on the hardware that is available to you. I believe that there is a thirty day trial period for Fast Raw Viewer, cost of the program (should it work out for you) is U.S.D. 19.99.
I don't know if the software that you use to generate the .tif files could potentially cause an issue. I normally use Photo Ninja (v 1.38b), occasionally Capture 1 (v 13.1.2.35) and very rarely Affinity (v 1.8.5) to create .tifs for Zerene Stacker. All .tifs gererated by the above programs (including the ZS output files) are viewable in Fast Raw Viewer.
Best Wishes,
Bob
