08amczb

Here is a reference from the past:

https://www.dpreview...party-batteries

The EN-EL15 series batteries has data contacts, it communicats with the body (I assume for measuring the charge and health of the battery). So it is possible to brake compatibility in theory.

Sony does this with the III-rd generation a7 cameras:

https://alikgriffin....7iii-a7riii-a9/

It starts, but then the battery indicator shows only an error instead of the remaining charge.

Did you tried to install older firmware or you just assume it's not possible?

I was thinking of a long weekend round trip in Spring, Ben, just
to explore and take some pictures. Any recommendations?

Budapest is huge. For a really short visit I would recommend to start with the Buda castle. The sides of the Danube and the site from the bridges is also an unmissable part of the trip. At Kossuth square the Parliament is an emblematic building and from Batthiány sqare there is a very good view to it.
From Kossuth square there is the city center within walking distace with the most important parts of the city.

For a longer visit there are many more places and thermal bathes in Budapest.

Here are some of my photos:

Parliament:

IMG171104_0015 by Benjámin Czétényi, on Flickr

IMG160120_0055 by Benjámin Czétényi, on Flickr

IMG160814_0037 by Benjámin Czétényi, on Flickr

Building abstract near to the Parliament characterizing Classical buildings of Budapest:

IMG160820_0027 by Benjámin Czétényi, on Flickr

Abstract of a Modern hotel on the side of the Danube:

IMG160820_0018 by Benjámin Czétényi, on Flickr

Piarista köz near to the Danube and Elizabeth bridge:

IMG160820_0011 by Benjámin Czétényi, on Flickr

Széll Kálmán tér:

IMG160625_0001 by Benjámin Czétényi, on Flickr

Chain bridge:

IMG160120_0053 by Benjámin Czétényi, on Flickr

Chain bridge From the castle:

IMG0866_141102 by Benjámin Czétényi, on Flickr

View from Gellért hill with the Castle on the left:

panorama1 by Benjámin Czétényi, on Flickr

View from the castle:

IMG160120_0023 by Benjámin Czétényi, on Flickr

The castle bazaar:

IMG160120_0005 by Benjámin Czétényi, on Flickr

The main church in the castle (Mathias church):

IMG151219_0014 by Benjámin Czétényi, on Flickr

Fhiserman's bastion in the castle:

IMG150704_0054 by Benjámin Czétényi, on Flickr

The castle:

IMG160120_0028 by Benjámin Czétényi, on Flickr

IMG160120_0007 by Benjámin Czétényi, on Flickr

The basilica:

IMG151219_0020 by Benjámin Czétényi, on Flickr

Elizabeth bridge from Gellért hill:

IMG150511_0015 by Benjámin Czétényi, on Flickr

In challenging lighting conditions you can measure the white balance (and exposure) in camera to the gray card. It ensures the card will be "gray", there will be no color cast on it. If the lighting changes in the scene, then you can choose a point to be "natural", but it won't solve the problem coming from the lighting differences.

If you shot in raw and have a photo about the gray card you can adjust the white balance in post production also.

For exposure metering the card can give you a similar reference as a light meter, it's independent from your subjects color. Your palm is also a pretty good target for exposure testing, just good to know.

I rarely use gray cards, I'am adjusting the white balance in post production in general, but it can save time from post if you shoot a whole session in the same lighting with preset white balance.

The new Sigma 70-200 F2.8 S is weather sealed also.

I'am from Budapest, from the sides of the hills.

IMG170616_0001 by Benjámin Czétényi, on Flickr