Probing and scoping MegOhm circuits?

[cupoftea]

Hi,
We have circuits with multiple MegOhm resistors in them. Rails are mostly 3V3 and 5V.
Resistors are as high as 22MEGs in places.

If probing the attached with say a scope probe, would you recommend a 100:1 probe?

Also , please confirm that the "22MEG" circuit is useless?......i cant see any property of a photodiode that could ever help the collector of the NPN to ever go high?
Must admit that 22MEG resistor does look like an "elephant in the room" to me though?
(LTspice of "22MEG" circuit also attached)

 

[FvM]

Thanks, i am not aware of too many 10Meg probes...the common ones i know of all have 1MEG shunt and 9 MEG series if 10:1, or 1MEG shunt and 99MEG series if 100:1?

Many 10 Mohm probes available on the market:

https://www.pmk.de/files/downloads/PML%20Series%20Datasheet.pdf

In earlier years, most 10:1 probes had 10 Mohm input R, increased bandwidth of modern passive probes often resulted in 1 Mohm.

Base node has 200 nA bias, 1 Mohm probe turns transistor off.