Unhandled Exception: Converting object to an encodable object failed: Photography

my cloud_firestore looks like this:

all_images:{imageUrl:[]}, couplePhoto:String, female:String, image_url:String, info:String, male:String

my model class:

import 'package:json_annotation/json_annotation.dart';
part 'Model.g.dart';

@JsonSerializable()
class Photography {
  final List<AllImages> all_images;
  final String couplePhoto;
  final String female;
  final String image_url;
  final String info;
  final String male;

  Photography(this.all_images, this.couplePhoto, this.female, this.image_url,
      this.info, this.male);

  factory Photography.fromJson(Map<String, dynamic> json) =>
      _$PhotographyFromJson(json);

  Map<String, dynamic> toJson() => _$PhotographyToJson(this);
}

@JsonSerializable()
class AllImages {
  final List<String> imageUrl;

  AllImages(this.imageUrl);

  factory AllImages.fromJson(Map<String, dynamic> json) =>
      _$AllImagesFromJson(json);

  Map<String, dynamic> toJson() => _$AllImagesToJson(this);
}

Currently, I haven't adminPanel to data insert. so, now I need to read data. When running this database, the error is coming in here.

    Future<Photography> postsMap = Firestore.instance
        .collection('photography')
        .document("0yUc5QBGHNNq6WK9CyyF")
        .setData(jsonDecode(jsonEncode(Photography)));