Thank you all for your pros and cons. Marc, I will agree with you that I am 69 now and retired from Shooting weddings etc. I do them on a need to do to keep me going. Been shooting since 1972 and Cant give it up totally.
I do buy now and why wait for later like you said. Plus, I don't want to pay the high price of NEW arrivals.
I will keep the D810 and try out the Pentax 645D. I can always sell it. Thank you all again.
It sounds like you mirror my own experiences. I'm semi-retired from my advertising career and from owning a photo business on the side (Fotografz, LLC) … like you, I also still shoot a wedding, portrait or small commercial job from time-to-time for a few operating bucks. IMO, at this stage of life, the more important thing is to keep the mind active and the juices flowing so you NEVER stop growing.
IF you keep the Nikon, then you may want to consider something even more different from a Pentax MFD. (Not dissing Pentax in any way, just saying that in the aggregate it may not offer a different enough experience/results to grow/challenge you).
I've pretty much kept to three different and
distinct types of camera systems that I've been slimming down to necessary "retirement" items: A B&W Leica MM Rangefinder, some sort of 35mm focal-plane shutter kit, and a MFD with Leaf-Shutter lenses. Each does what it was designed to do better than the other two. So, it is easy to select which one to use for each creative challenge or idea, (although, I'll admit to considering the MFD first because I'm biased to the results I've gotten compared to a FF DSLR or Mirrorless 35mm including my current Sony A7R-II). The obvious exception to this is when I select the Leica MM for exploring decisive moment street and candid humanistic B&W work, (which doesn't fit into your listed scenarios).
A couple of used choices could be: A Hasselblad H4D/40 or 50 with just a few key lenses. Or a Leica S2. The H4 is the first H model featuring True Focus APL which is an unsung stroke of genius IMHO and experience. The S system is a dual shutter type camera so offers the best of both worlds, although the CS lenses may be to pricey even used.
I exclusively use MFD for portraits and group shots (Environmental portraiture, bridals and formals at a wedding, business portraits, etc.). I also use it for ALL commercial work in studio and out. I don't fret about high ISO since I don't shoot any of this work in crappy light … ever.
I use 35mm for travel by air, vacation walkabouts, long lens work, fast moving subjects, the convenience of a zoom lens, and low light scenarios … and the truth be told, for stuff that I just need to get but don't all juiced up about (like wedding processionals and cake cutting must haves, or family shots destined for Facebook
. I honestly do not give a rats bottom for standard 35mm gear, but it is a necessary evil for some type of work.
Enjoy your retirement and get on with it now … tick-tock!
- Marc