wdross Loc: Castle Rock, Colorado

Gene51, an UHH member. He shoots professional and he does his researching of camera information very well. And, yes, he has found the Sony RX10 mkIV to be one of the best bridge cameras.

But the OP did not specifically state he want to move from a system camera to a bridge camera. The suggestion has been put forth if that is the direction the OP wants to go (and possible equipment wise, it's still a good suggestion). The assumption I made about the OP's possible needs is he would like just a smaller and lighter system without too much changes in quality and function. The Sony RX10 mkIV does have an even smaller sensor than the 4/3rds and will move the smaller sensor characteristics even further (even more DOF and an even lower limit to ISO noise). We do not know if the Sony RX10 mkIV will meet the OP's DOF and/or ISO needs. It actually could end up that APS-C will be the format to meet his needs.

Gspeed Loc: Rhinebeck, NY

Check out the Lumix-10

https://m.dpreview.com/reviews/panasonic-lumix-dmc-lx10-lx15

Delderby Loc: Derby UK

It is not asking a lot. I use Panasonic M4/3 retro rangefinder style with a 14-42 PZ and a 45-175 PZ which is 28-350 equiv FOV. There are, of course, wider lenses. There is a great 14-140 - you could ask Linda from Maine.
The Panasonic G9 DSLR style and GX9 retro rangefinder style are both top of range, superb cameras.

Ched49 Loc: Pittsburgh, Pa.

You want to give up all your Nikon DSLR's and your asking suggestions on what to buy...isn't that putting the cart before the horse?

wdross Loc: Castle Rock, Colorado

He probably is looking at UHH to help "whittle down" what to start looking for and what to be looking at. The OP has probably had his Nikon system a fair amount of time without questioning much. I suspect that the system is older and heavier than what they want to shoot with now. Everyone has a different idea as to how to start looking. For the OP, this is not "the cart before the horse"; just a good starting point of opinions. Based off the answers, I do not think the OP will be looking at Hasselblad.

analogman

To all of you who replied with polite useful answers, Thank You!. I am carefully considering all that you have given me. I am turning in my Nikon gear because my health is failing me rather quickly and I tire of lugging all my gear around. Learning to do more with less has been a huge challenge that I preferer to for go. Thank you again for your time. Analogman

mwsilvers Loc: Central New Jersey

Deleted

wdross Loc: Castle Rock, Colorado

I am sorry to hear about your failing health. We all hope our suggestions will help lighten the load and help you to keep what health you have left for a long time.

For a recap, if you no longer want to spend time changing lenses, Gene51's and others suggestions of the Sony RX10 mkIV or similar quality camera is a good one. If you would still like the option of being able to change out your lens for a specialized macro, ultra wide angle, or telephoto lens, and want to minimize the weight and size the most, I suggest a 4/3rds camera. Your want for an 18-200 angle of view is very nearly met with the Olympus 12-100 on a Panasonic or Olympus body. The 12-100 is capable of half lifesize too. If you are finding yourself shaking more while handholding, I suggest the Olympus E-M1 mkIII for its superior image stabilization (I just purchased one 2 weeks ago and the increased stabilization is very discernible at a handheld 840mm angle of view; 7 to 8 stops of stabilization).

I personally think if you spend the time at the camera store with the numerous suggested equipment in your hands, you will not have to learn to do more with less and will have to forego almost nothing.

Ched49 Loc: Pittsburgh, Pa.

Since you have to be familiar with Nikon's feature set, i would suggest look at Nikon's mirrorless cameras.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

I shoot all Nikon full frame and have a collection of lenses to go with them. In 2017 I was going on a trip and didn't necessarily want to bring all that gear with me, so I picked up a Sony RX10m4. It was, and in my opinion still is the best bridge camera in production. However, it is not a replacement for my full frame gear.

Thomas902 Loc: Washington DC

"...health is failing me rather quickly..."

analogman possibly you may be having some emotional issues in regard to your current health status (which is indeed very common). And actually could be related to "depression" which is indeed treatable...
If you have been feeling down for an extended period it may be a symptom of Chronic Depressing.

From the DSM 4 Criteria for Clinical Major Depression
Source: https://www.ncbi.nlm.nih.gov/books/NBK36406/table/ch1.t1/

Depressive Diagnoses
Major Depressive Episode:
- 5 or more depressive symptoms for ≥ 2 weeks
- Must have either depressed mood or loss of interest/pleasure
- Symptoms must cause significant distress or impairment
- No manic or hypomanic behavior

Minor Depressive Episode:*
- 2–4 depressive symptoms for ≥2 weeks
- Must have either depressed mood or loss of interest or pleasure
- Symptoms must cause significant distress or impairment
- No manic or hypomanic behavior

analogman if you are experiencing the following symptoms you should likely seek medical help
Depressed Mood
Markedly diminished interest or pleasure in most or all activities
Significant weight loss (or poor appetite) or weight gain
Insomnia or hypersomnia
Psychomotor retardation
Fatigue or loss of energy
Feelings of worthlessness or excessive or inappropriate guilt
Diminished ability to think or concentrate, or indecisiveness
Recurrent thoughts of death (not just fear of dying), or suicidal ideation, plan, or attempt

The good news is your General Practitioner can start you on a medication like SSRI's which are a class of anti-depressants that are very effective and have the least side effects.

That said... Please do not self medicate with alcohol which may only make matters worse.

I trust you'll be able to again find joy in your golden years that lay ahead.
We all must deal with death in a rational manner...

"Neither the sun nor death can be looked at with a steady eye." Francois de La Rochefoucauld

All the best on your wonderful journey analogman.
Always remember when one door closes another likely will open :)