Pentax-Z-1P AND Z-70 camera meters

While fine tuning my camera meters as explained in John Shaw's book-"Nature Photographer's Complete Guide To Professional Field Techniques", I find that 400 ASA film has to be set at 800 ASA and the film thus rated gives proper exposures. Is something wrong with both the camera meters ?

I have a PZ-1 that I usually only shoot with color film. With color the factory specs work on my camera. The times I do shoot B/W with this camera I find that the meter under exposes the film. I lower the film speed by about 1/3 the rated speed.

Are you shooting color or B/W?

I shoot both. Have you tried to check, on the basis of sunny 16 rule, (i.e.taking a reading of grey card in bright sun as explained in Shaw's book)whether the camera meter gives correct values as per film asa set on the camera ?

I haven't read Shaw's book so I don't know how my test will apply to his. Today is our first sunny day since you posted and I just tested my PZ-1.
ISO 100 indicated shutterspeed 90
ISO 200 indicated shutterspeed 180
ISO 400 indicated shutterspeed 350
When I read the greycard with my Zone VI modified Pentax spotmeter my exposures showed I would need to increase the film speed by 1 stop, 100 goes to 200 etc.

Hope this helps you. All I've done is confuse myself

Dear Ron, There should be no confusion. Your spot meter reading appears to be correct since my pentax spot meter gives the same reading. You can fine tune your camera meter by reading a grey card in sun. If you are using 100 asa film, proper bright sunlight exposure should be 1/125 sec at f16. Keep your camera in hyp.manual mode and set this exposure value (by setting shutter speed and aperture values manually)and then adjust film asa setting on your camera to find which asa matches with this expoure.Regards,Hansraj.