@php
    $render_number = $render ? $render : 1;
    $renders = [
        'f1_k1_t1',
        'f1_k1_t2',
        'f1_k2_t1',
        'f1_k2_t2',
        'f2_k1_t1',
        'f2_k1_t2',
        'f2_k2_t1',
        'f2_k2_t2',
    ];

    foreach($renders as $render) {
        $images [$render] = get_field($render . '_render_' . $render_number);
    }
@endphp

<figure class="renders">
    @foreach($images as $key => $image)
        <img data-render-index="{!! $key !!}"
             src="{!! $image['url'] !!}"/>
    @endforeach
</figure>